The Stovebolt Site Forums The Shop Area The Electrical Bay Starting difficulties - 1966 Suburban

I have a 1966 Carryall. Included with it were a Motors 1969 Manual (for 63-69) and a Fix Your Chevy book. Both seem to indicate that 2 or more wires connect to one of the starter posts. I have one wire going to each post. One yellow, one black. The ammeter in the dash appears to work so it appears it's wired right. Were there just 2 wires, one for the positive and one for the negative terminal?

How about a little more information, like which engine it has, and whether it appears there has been any modification to the wiring system? The wire colors don't sound right for a factory wiring harness. Normally, there will be a #4 gauge battery cable attached at the top of the solenoid, along with two red-insulated fusible links in #10 gauge. One fuse link feeds the ammeter, and the other will power the constant-hot part of the fuse block and maybe the headlight switch. The "S" terminal on the solenoid will have a purple-insulated #12 wire, and the "I" terminal will have a #16 or #18 wire going to the + terminal of the coil. Not sure about the insulation color on that one.

Can you describe the starting problems a little better? Is it a "no crank" situation where the engine doesn't turn over, or a "no start" problem where the engine turns but refuses to run?
Jerry

In looking at my post, I see I made a typo. I do not know what was wrong with my fingers. I just replaced a coil. Tests showed a bad primary in the thing and since it was 45 years old, it was replaced. It's the 2 posts on top of the coil I was referring to. I hope to work on the vehicle some this afternoon. It cranks but does not even try to start. I just replaced the battery as well. The last time my f-in-l tried to start the truck, he failed.

I've still got the distributor to check and the plug wires. I hope to do a spark test this afternoon. I just needed to know if these vehicles used a resistor wire, ballast resistor or something along that line.

BTW, the engine is a 283 ci v8. No majjor changes to the wiring. My f-in-l, the privious owner, did add things like radios, lights, alarms and horns.
Mike

I'm pretty sure that by 1966 they had gone to a resistor wire from the ignition switch to the coil. It's a fabric-insulated nickel/chrome wire that drops the voltage to about 9.5 volts with the engine running. To test primary voltage at the coil, be sure the points are closed, turn the ignition switch to the "run" position, and check the voltage at the coil (+) terminal. It should be about 9 volts. Voltage at the coil (-) terminal with the points closed and the switch on should be almost zero. With the points open, the reading will go up to the same voltage as the battery at both coil terminals. There should be a bypass wire from the I terminal at the starter solenoid to the coil + terminal. During cranking, this applies full battery voltage to the coil and bypasses the resistance wire. Be sure you've got clean, properly-adjusted points. The most common cause of a no-start condition is dirty or burned points, or insufficient point gap.
Jerry

I just checked for spark...none. Now I have to wait until I can afford to get the other parts, distributor cap, rotor, points and condenser.

Here's a photo that shows how the coil was wired. This was the original 1966 coil.

https://picasaweb.google.com/108235...Gv1sRgCOKa1L7i2OHfXQ#5668998755058922018

Mike

I used to fire mechanics in my shop for using the "shotgun" approach for fixing a problem. Invest in a $5.00 digital multi-meter from the local parts store and figure out where the voltage loss is happening. You've got the manuals that will give you a basic idea of the ignition circuit, so start at a logical place like the ignition switch, and do some circuit tracing. I've gotten some of these old rigs running with nothing more than my girlfriend's fingernail emery board to clean up a set of oxidized points. The problem is probably very simple- - - -just don't get discouraged and start throwing parts at it by the bushel basketful.
Jerry

I did test the coil and found it had a bad primary coil. I had my findings double checked by a mechanic I've dealt with for 20+ years who now works at Autozone. So I don't just use the shotgun approach. I figured that with a truck that sat for at least 10 years without running, that has no spark and had to have squirrel nest material cleaned out of it that I would begin with the basics.

First, clean things up. Then get a battery so I would be able to test it. After the battery, I tested the coil. It was bad, so I replaced it.

BTW, I already did by a cheap VOM and that's how I checked the coil. I checked the values against those listed in the Motors Manual. I also just got back in from testing the coil as you suggested. I may not be doing this right. I get the same value at the positive and negative posts. 12 volts in 'on' and 9 volts when cranking. I put the red (positive) lead on the post and the negative to the valve cover for ground. Did I do this wrong?

Mike

PS I am not a mechanic by trade and no one I work with knows how to work on cars. I have managed to rebuild a Quadrajet carburetor in a 79 Olds and restore it to running condition so I am willing to try to repair this myself if possible.

You haven't established whether or not there is a circuit from the coil (-) terminal to ground. The points do this. Take the wire off the - coil terminal and use the ohmmeter function of the meter to check the resistance of the points. Take the distributor cap off during this check so you can see whether they are open or closed. With the points OPEN there should be a very high resistance from the wire you just removed from the coil and ground, several thousand ohms. Tap the starter until you see the points close, and check resistance again. Now it should be VERY low, less than one ohm. The most likely cause of a "no spark" condition is dirty points. If the "points closed" resistance is over 1 ohm, take the point assembly out, and buff the contacts with extra-fine sandpaper, then clean them thoroughly with alcohol, lacquer thinner, or spray carburetor cleaner. For a rough guess point gap setting, use a piece of business card or something of similar thickness to set the gap with the rubbing block on one of the high spots of the cam lobe. I'll be surprised if it doesn't have a spark when everything is reconnected. In over 50 years of doing professional mechanic work, I have only seen about 10 failed ignition coils. It's not impossible, but it's VERY rare.
Jerry

Ok, let me see if I have this. The wire on the coils (-) post (a black wire) is to be disconnected from the coil. To ask a dumb question, where do I put the leads of the meter in order to get the resistance of the points? According to the Motors Manual, this wire should go to the distributor.

In the original coil, I got a good reading on the secondary coil but not the primary. I followed the examples in the book in order to test it. Autozone also tested it and declared it bad. I would not have replaced it without testing it first.

If I hear from you by the morning, I will run the resistance tests before I have to run out of town errands.

The purpose for checking the wire from the negative coil terminal to the distributor is to see if the points are providing a ground to the coil primary winding. Attach the ohmmeter leads to the wire going fron the - terminal to the distributor, and to an engine ground like a valve cover bolt, carburetor linkage, etc. If the points are conducting, you will see a very low resistance. This MUST be done with the wire disconnected from the coil or you'll get a false reading. Points closed- - - - -low resistance. Points open- - - -very high resistance. Unless this is happening, you'll never get any spark, no matter how many parts you change. The points are the switch that turns the coil on and off, creating the spark.

If the primary winding is actualy open-circuited, you've got a bad coil- - - -a very rare failure. The normal resistance of a primary coil winding (+ to -) is about 2 to 3 ohms. If the ohmmeter is connected between the + terminal and the high-voltage tower that produces the spark, the resistance should be around 10,000 ohms. Good luck!
Jerry

I'm sorry, I'm still trying to figure this out. Once I disconnect the wire, do I put one lead on the now open end of the wire and the other connector to ground?

I'll try this once it gets light here. I work in my driveway so I'm stuck to daylight hours.

BTW, is there a good book on auto electronics? One that would apply to these older vehicles with simpler electronics. I know there are books out there but I'm not sure which would be best for an electrical novice.
Mike

I set the multimeter to Ohms. I put the black (COM) lead to the intake manifold for ground. I put the red lead at the end of the wire that had been connected to the coils (-) post. The readout was 0.L. This was whether the key was on or off and the same if points were open or closed.

So one lead was touching the disconnected wire and the other the manifold. I did it wrong, didn't I?

I'm using an Innova 3320 meter.
Mike

You did it exactly right. Did you REMOVE THE DISTRIBUTOR CAP? it's absolutely necessary to observe the position of the points, open or closed. If the points are open, that's a normal reading. It's not necessary to turn the ignition switch on; you're just checking for continuity and the meter has its own power source. With the points CLOSED, the resistance should read less than one ohm.

Since the meter reads "overload" (O.L.) with the points closed, my suspicion was correct- - - - -the points are dirty or burned. Either clean or replace them, and the spark will be there. That window-type distributor uses a set of points that should come pre-adjusted so the engine will start when they're installed. If you're cleaning the old ones, and you don't disturb the screw adjustment for point gap, it should not be necessary to do much, if any gap adjustment. The standard point gap for that distributor is .019", which is slightly over the thickness of a business card, but thinner than a credit card. Be sure the rubbing block that contacts the distributor cam is at the highest possible point on the cam when you set the gap. A 1/8" Allen wrench is used to set the gap on the points. Turning the screw clockwise decreases the gap, CCW increases it.

Clean or replace the points, reassemble things, and the spark should be there. Good job so far!
Jerry

I spent the day at my in-laws helping remove old trash so they can move. My f-in-law gave me the 66 Burb. Well, when cleaning out his garage, I came across points, distributer cap, vacuum unit and condenser in the original boxes with a receipt from '95. No rotor, shucks. In addition, I found a Rochecter 2 jet carburetor with choke. It's pretty dirty and may not work with my setup but I'll hold on to it. There were also several starters and alternators. I have to figure out what they go to.

While in town, I gave this test some thought. The wire came from the negative post on the coil. The truck is wired with negative ground. So didn't I just test neg to neg?

I did remove the cap so that I could monitor the points. They are fairly worn with a dusty buildup. If I do not need the ignition on, I could rotate the engine by hand at the fan couldn't I? This would give me better control. The solenoid on my starter is a bit flaky.

I did not know it meant overload. This is a window type distributor cap.

My day off is Tuesday. I'll try again then.

Thank you for the help. Any good auto electrical books you might suggest?
Mike

Buy points, cap and rotor first, it's cheap,(you need that anyway)If you don't have spark after that, then post how you are checking spark. The Ohm stuff can be later, you are wasting time trying to find which of those cheap to buy, 50 yr old, parts is bad, if any. Lincoln will help you after that, you are getting a little confused and will blow it and we won't know what you did. you will have spark after replacing that stuff with good batt and coil now. Bad Plugs and plug wires would fire a little. We can check for proper hot and gnd after new parts. I don't believe in throwing a bunch of parts at it either, but that stuff needs replaced. Why screw around with point cleaning and gapping and all that, if the coil was bad maybe tha capacitor is bad (make sure you get that too)Total will be $30-40.

Sorry I was writting my post at the same time you were and also did not see Lincolns last part in his last post??????? Am I loosing it? Disregard if he or you are already doing some of what I said.

Of the parts you mention, I only lack the rotor. I can see if Autozone or O'Reilly's has that part.

In talking to my f-in-law today, he said that it worked when he last drove it and the next time it just would not start. He did not know if the distributor failed or what.
Of course that was maybe 20 years ago.
Mike

Make sure you are disconnecting the ground off the battery while doing all this parts install. Did you get a capacitor? Put it all back together, check all wires carefully and then see if it fires at all. Tell us what it does. No fire? no spark? spits thru carburetor? won't even turn over? starts right up? The best way to check spark while cranking is to use a spare plug. Pull off a plug wire and put it on the spare plug and hold the plug against a good ground and watch for spark. you can also just stick a bolt or nail in the plug wire end and watch. It is better to leave all plugs in the engine if you can.

I picked up a rotor after work. Thanks for the tip on the battery. I have points, condensor, rotor, distributor and plugs. I only bought the rotor, battery and coil. I'll start work as soon as it warms up in the morning. I'm not expecting to get it running well but I want to iron out the electrical problems first. One can of worms at a time.
Mike

I believe I have followed all the suggestions. I am still at square one. I cannot tell if I am getting spark because I cannot see the plug from the drivers seat as I crank the engine.

I cannot trust my electrical testing because I know nothing about automotive electrical. I have promptly traded in vehicles in the past once they displayed electronic glitches. I can set my multimeter to ohms and put both leads on the frame just 2 inches apart and the reading is 0.L. Touch the leads and resistance is 0.00.

Not sure what to do next. How do I test my meter?

BTW, the points were worn paper thin.
Mike

You need a helper or a remote starter. You can cross the field and batt posts at the solenoid to operate the starter. This can be done with a screwdriver, but it is much safer with a remote starter wire tool. You can make this tool with some wire, 6 to 8 feet should be plenty, and two alligator clips. Your starter solenoid should look like THIS ONE >CLICK< Cut the wire to two equal lengths and install an alligator clip on each one, click one wire to the batt. feed post, and the other to the "signal from ign. switch" post. Now turn the key to the run position, and make sure the truck is in park or neutral with the brake set. When you touch the two wires together the starter will engage, there might be sparks and that could alarm you at first, but don't panic. Now you can get where you can look for the spark of ignition and operate the starter from under the hood.

That sounds like a handy tool to have. I remember the screwdriver method from years ago. Not too kind on the screwdriver if I remember correctly.

Some questions:
What gauge wire do you recommend? Something fairly heavy?
The alligator clips connect to the posts on the solenoid on one end and I hold the other ends. Won't there be a nasty jolt when I touch the wires together?
Mike

The wire gauge should be similar to the wire on the starter ign. post. They used to sell these pre-made with a push button to engage them. I did a search but could not find one. There will be a spark but nothing dangerous.

EDIT: Here it is.

Like these?
remote starters

Yeah, if you go for THAT ONE you won't have to worry with the key. The third wire will go to the other post bypassing the trucks ignition switch. You will obviously still need to make sure of the park or neutral thing.

I have sitting in front of me the cable that goes from the coil to the distributor. My meter shows 10K ohms or more of resistance. A continuity test fails because it requires a resistance less than 120 ohms. I do not know what the resistance of a normal spark plug wire is.
Mike

Take the longest plug wire still attached to distributor but taken off the plug and plug still in engine and run it thru the gap between hood and windshield cowling and make the bolt or nail snap spark against something you can see thru or around the windshield. Be creative. As to your meter: You touch the two leads together on your meter to check it, not to anything. It should then read 0.000 or very low. The OL means Open Loop. When you touch them or a frame you are check for continuity, that's all. Just that two things are electrically connected. Open Loop means they are not. If you touch the probes together and you get OL, you need a battery in meter or you have it set wrong. Read the instructions carefully. As far as checking circuits for whether they have current (amps)or voltage, that's a different setting on the meter. Do not check for continuity on anything that has power on it. Continuity would be used for example to see if the wire from the coil to the points is continuous, connected (continuity). You need to search the internet, use your computer more, and learn about the electrical system basics. It's not rocket surgery, we all had to learn it. We are happy to help but you can't be totally unwilling to check the web also so you have an idea of what you are doing and what we are saying. We can not do all the work and study. http://www.familycar.com/Classroom/ignition.htm (some basic ignition diagrams do not show the other wire from + side of coil to starter)

You don't need to check the ohms of a plug wire!!!!!!!!!!!!!!!!!!! Check the spark first, then report. Your remote starter is your wife, girlfriend, boyfriend or friend or neighbor or do what I said. Mike, everything is new, and if everything is hooked up right, you will have spark. Did you try to start it? What does it do????????????? now with everything new????????? Put a tiny bit of gas in the carb and start it! My humble suggestion is put the meter away. Check the wiring according to the diagram I provided and any other diagram from a basic ignition book and then try to start it.

It turns over the same as before. No change. Nada, zilch, nothing. No spark at the plug. I even took the cable from the coil to the distributor out of the distributor and held it next to the firewall to see if I got a spark. Nothing.

To test the plug, I put a new plug into a cable and grounded the body of the plug against the frame, nothing.
Mike

I do try to find info from a variety of sources. My internet is dialup due to where I live and there are no local schools that have shop courses. My income is limited and I cannot buy every book out there. If you know of a good one, I will check it out.

I do not know what kind of alterations may have been made to the electrical system. My f-in-law said it worked when he parked it but he never could start it again. Then he had a stroke and the truck sat for years.

I have a new battery, coil, distributor cap, rotor, points and condensor and no spark. I will see what I can find out.

Are you sure your points are opening and closing as they should and are gapped properly. If they are, then is electric power getting to the points and/or the coil. I've said the following a million times at least "A new part does not necessarily mean a good part" so my next logical suspicion is that the coil is no good.

First let's old-school hot wire that truck. Since I have typed most of this message, I can't go back and review all the prior posts so excuse me if I repeat or say something redundant.

Two, I am assuming that you are working with all functional parts.

Three, pull the distributor cap and observe the points while cranking the engine to make sure they are opening and closing. also observe the direction of the rotation of the rotor.

Four, run a wire from the positive side of the battery to the "+" terminal on the coil, this will be the side that does not go to the distributor points. While doing this make sure that the coil is not wired backwards. The two posts should be marked in some way indicating one of them as positive and the other as negative or distributor.

Five, replace the distributor cap and make one final check of the firing order. Are the wires in order and the same direction as the rotor was turning in step three?

Six, a shot of starting fluid down the throat of the carb and a crank should fire it up. If it don't start now we may have to take a look at the timing chain or timing gears.

Now for your internet connection, Wildblue.net is running a Gov't program for situations like you describe where no other than dial-up is available. I got a sweet deal for $40/month just recently. It would be worth looking into to see if you qualify.

I did not mean go to school, I meant read the internet. I realize dial up is slow. Use it at midnite or 4 in the morning. you are doing great. You have not said whether you have double checked all the ignition wiring using a diagram. If it does not spit thru carb it is probably OK timing gear wise. Obviously if you do not have spark at coil tower then problem is up stream from there. Do your diagnosis starting from there and working towards battery using the ignition diagram. I know you have not taken the distributor out so it almost has to be OK.......But if Father-in-Law did when troubleshooting it then who knows? If it is all wired properly, with new parts including resistor (ballast) if equipped, then it's bad parts or points not adjusted as been said or some wire shorted. If you need info on how to check if distrib is "clocked" correctly, let me know. Small block Chevy: No 1 is drivers side front Cylinder and Distrib rotates clockwise.

I have the wiring diagram I found on this site. I plan to get a light on Saturday that I can hang from the hood. Between that, degreaser and a lot of rags, I will trace those wires going to the pos and neg posts on the coil. Since everything else has power, these seem to be the most suspicious to me.

The points do open and close.

Thanks for the tip about WildBlue internet. It will have to be better than dialup. I qualified for the same $40 deal.

F-in-law did like to tweak. He has a pull knob for throttle installed. He used it on cold mornings to warm up the truck after he had released the choke. He also added emergency flashers, air horns w/ compressor and a siren type alarm. I have questioned him about an ignition kill switch and he says he did not install one.
Mike

hot wire it as described above. then you will know if it runs or not before you put too much money into it.

Now you are talking Mike. Go for it until your figure it out. BTW Some of those old Chevy logo flashers can be worth $100.

Ok, I tried to hot wire. Nothing. I used a 12ga wire and alligator clips.

I traced the two wires attached to the coil. The black wire runs from the bottom of the distributor to the negative post of the coil. The yellow wire goes from the positive post of the coil and down into the wiring harness.

One interesting point. The yellow wire has what appears to be a T type connector. It looks like the wire may have continued on elsewhere. The prongs on the connector are at a right angle to the wire. I can find no loose wire around the distributor.

The coil has printed on it that it requires a resistor. Could the store have given me the wrong coil?
Mike

If it doesn't spark and run by hot wire, the coil is no good or the points condenser is bad. Again this is assuming the points are installed correctly. Inside the distributer, there is a black wire that comes from the coil. You need to check that wire to make sure it is not broken anywhere. You can do this with your ohm meter. If that wire is good and hot wiring it did not work then the coil HAS to be bad.

Have you done a compression test on the engine? This would tell you if you have stuck valves or a timing chain problem. It would be a good idea to know this before trying to run the engine to avoid doing any further damage if it is out of time.

If that were my truck I would pull the intake, heads and timing chain and inspect everything before trying to get it to run. Those old 283 engines are getting hard to find and I wouldn't risk ruining it.

hmmm, new coil, points and condensor.

I'll sell it before I do the other work. I have neither the knowledge, time or financial means to do that kind of work. I really thought that I would at least get a spark to a plug. I can't even do that.

BTW, I also have no garage. I hate leaving a vehicle in pieces in the yard/driveway.

Mike

Calling all Texas stovebolters, MikeR needs some hands-on help.

Where in Tx. are you? Maybe there are some close-by Tx. stovebolters that could drop in and give you some support. That truck looks way too nice to not run.

Sorry about getting bummed out. I have gone over the wiring diagrams in the Motors manual and they show that a negative ground system the negative post of the coil goes to the distributor. That is how mine is wired. The wire goes in through the bottom of the distributor so I will have to open the distributor again to try to run a continuity test on it.

I do not quite understand the hotwire. I can see where I'm giving the positive feed straight to the coil and bypassing the ignition switch but how would the starter get juice?

I do not have a wiring diagram other than what was on this site. It shows the positive side of the coil going to the distributor. This contradicts the Motors manual. Would I kill the coil to reverse the wires? Put the distributor wire to positive and the harness wire to negative?

I'm out at Lake Tawakoni. That's 50 miles east of Dallas.