The Stovebolt Site Forums The Shop Area The Electrical Bay starts...doesn't stop

My '58 Apache w/ 235 started unexpectedly the other day. I was cranking to find TDC after it had been off for several years and it just kicked over even though the ignition was off. Fortunately my hands were clear of any moving parts...

I have replaced the engine and wiring harnesses up front while the truck was out of commission, so I'm guessing I got some wiring wrong. Original ignition switch. If anyone can tell me where to start with trouble shooting, I'd be mighty obliged.

Jerry

hey Jerry! first thing to know is when ya don't want it to start, pull the main coil wire before cranking, saves accidents

sounds like you got the coil wired wrong - there's 2 wires, one from the side of the starter actuator that energizes the coil direct when the starter is engaged, one that goes thru the ignition resistor, both should go thru the key switch ... if you've got a shop manual, check the wiring diagram in it, shows all the details

Bill

Hey Jerry, I'm a New Guy with a '58 Apache as well.Maybe we can assist each other down the road ? I am going to be posting some pix as soon as my 25 year old son can do it ! Good luck with it all. RAK

Did it keep running, or just hit a time or two and then stop? Some ignition systems have a resistor bypass wire built into the starter switch that supplies full battery voltage to the coil + terminal anytime the starter is cranking over. Disconnecting the coil wire at the center tower of the distributor cap and grounding it is a surefire way to keep it from starting unexpectedly.
Jerry

Thanks for the replies. I just wasn't thinking that it would kick over. It was stupid. The coil wire is now disengaged when appropriate for safety.

It kept running until I choked it out at the carbs. The starter had disengaged long before. I'll check out the coil wiring with the manual.

Hey RAK, glad to swap stories and information. My truck is not quite stock, but I do run taller gears, two carbs and dual exhaust. After the mechanical bugs are worked out, I'll start with body work....

OK, the coil appears to be wired correctly. long dk. green from + terminal into harness, - terminal black wire to distributor terminal.

I took out the ignition switch and found a red (battery?) wire on one of the accessory terminals(with the pink wires to turn signals and horn). I moved it to the other terminal set. Could this have been the issue?

Carbs are out of the truck for work so I can't actually try it

I did find continuity to both sides of the coil from the battery with the ignition switch both on and off, but don't know if that is good or bad.

bad, very bad, you'll wind up with a fried coil in no time and a dead battery, there should only be power to the coil when you turn the switch .... see the switch connection diagrams at the end of this page - power to the coil should only happen when the key is on and when the starter is depressed, if wired properly - if it starts when cranking with the key off [shouldn't] it should shut down as soon as you let off the start pedal

Bill

Continuity only means an unbroken path for current, it doesn't mean a circuit is energized. Was there voltage present when measured with a voltmeter? Isn't this correct?

Stuart

the switch is there to break that continuity, just like the foot stomp makes and breaks continuity when depressed - if there's unbroken continuity 'tween battery and coil with the key off, what's to keep it from being "energized" with a battery connected?

Bill

Bill,

It sounded like the circuit was being tested with a meter on 'OHM' function. The meter has a onboard battery it uses for this function to find a complete path from probe to probe. This doesn't mean a circuit is powered. If the points were closed, a Ohmmeter would indicate 'continuity' between the coil and any other grounded spot on the truck. I don't think this is the same as showing voltage, which would indicate the circuit was energized.

I haven't read the full thread so I'm not sure what was being driven at...my comment was just to clarify that a circuit that shows continuity doesn't meant a circuit that is powered. Sorry if I have confused the issue.

Stuart

Hey Jerry check it out ! RAK

when i ran a whole new harness i made i needed to place a diode on the alternator output wire as it was feeding 12v to my coil after the key was turned off.
the diode stopped that

OK, I imagine I caused any confusion. The coil is new. The wiring harness is new. The installer is new....

First, the battery is disconnected until I figure this out unless I am trying to fix it.

I am using a Sperry SP6A with the switch turned to 50 in the black "V...." section.

I put one probe on the non-grounded side of the battery and the other on either terminal on the coil and get the same reading as when I put a probe on each terminal of the battery.

Bill, following the diagram on image 58 for the push button 6cyl. I moved the red "lite sw." wire from an accessory terminal to the proper terminal but still get the same readings at the coil terminals if the ignition switch is on or off.

I have to confess that the diagram in my manual looks more like the V8 diagram in image 59, though. It's 2 AM, or I would check, but I think I have two green wires and I definitely have a three way plug on my harness. Maybe I have a V8 harness on an I6.

The pink accessory wires are on two different terminals. Would that matter as long as they are on two of those four (five?) in that group?

As I recall, the starter always cranked when the pedal was depressed, but the engine would not start (before I did any work on this truck). There was always a battery drain, also.

Thanks for all your help this far.

Just saw your post Caroline or Jim. This is a bought harness and I still have a generator, so I think that is not my problem, but you have got me thinking about looking into harness issues.

Good lookin' truck RAK! I bet mine was that color long ago. You've really updated the electricals, too. How do those headers sound?

I broke my camera, so no photos for you all yet, but Mine is a long bed, 3 on the tree. Also has dual offy intake with bad-a$$ original singles on it. Dual Fenton exhaust.

All my wires are as per the diagram in my manual. The ignition switch turns the instrument cluster on and off, but leaves the coil on.

Could the resistor be bad? How do I check?

Could there be a short causing this? How do I check?

Kwangtzu,

I haven't been following this thread closely. I'm going to make some assumptions which might be wrong. Your truck is a 12 volt system with a stomp starter. If you don't have a internally resisted coil then there should be a ballast resistor on the firewall and a terminal on the starter switch which acts as a bypass terminal.

If you turn the key ON, the coil should be powered. If you turn the key OFF, there should be no power at the coil. The presence of voltage would be measured with a voltmeter from the key side (+) of the coil to a good ground.

If there is a ballast resistor in the primary circuit to the coil it will be bypassed when you push the stomp starter down. This powers the coil directly from the small terminal on the starter switch. There should be only one small terminal and only one wire on it. This wire would go to the coil OR the coil side of the ballast resistor.

I believe trucks of this year equipped with solenoid starters had a rather involved key switch that feed full voltage through to the coil on START. Your truck evidently has a stomp starter which would involve a ON-OFF-ACC key switch. The coil should not be powered in ACC either...only in ON.

I usually ground one probe of the voltmeter or ground the alligator clip of the tester and search for powered wires or connections with the other probe.

Stuart

Good assumptions, Stuart. 12V stomp. There is a resistor on the firewall.

The wire from the starter runs back up to the ignition switch.

I got two pointers from your information:

1) I haven't been testing correctly. I'll change that next time I'm working on it.

2) There should be three positions on the ignition switch. This makes me think the switch is bad because I can only find two positions.

So maybe I need a new ignition switch?

Thanks

Jerry,

A '58 is not a rig I'm familiar with..Bill (red58) knows these inside and out. My guess would be, if that is the stock switch, that it should have ON-OFF-ACC positions.

The starter switch will have a large lug with BATT positive connected to it. It should also have a #10 or #8 wire attached to the same lug which is output from the charging system. If you do have a ballast resistor that is functional and you do have a stomp starter then you have to have some type of bypass system to make that circuit work.

With a ON-OFF key switch and stomp starter, the only way to make the ballast resistor work is with a bypass terminal on the starter switch. This isn't connected to the large BATT lug but rather to a small terminal hanging off the side of that starter switch.

I don't know how it could happen but you need to make sure that small terminal has NO power when the truck is sitting dead in the driveway. I'm not sure if the wire you mention that runs back to the ignition switch is from this small terminal, but I would find that strange. The ultimate destination for a wire from that small bypass terminal is either coil + or the coil side of the ballast resistor.

Stuart

the foot start has a 2 position switch, on-off, no ACC [originally], so you have a 6cyl sw, but the terminals on the repro aren't necessarily as original [and different year diagrams show either the 6cyl or 8cyl switch, not both] .... the starter side terminal wire does go to the key sw - from the key sw it goes to the coil

when the foot is stomped, power goes from the starter to the sw ["violet" to "ign2"] then to the coil [dk grn from "ign1"] .... when starting the coil is actually getting power from both starter [full 12V] and the resistor [8V or so] - when the starter is released, the power to the coil then goes only from the key [heavy red wire on batt term from ammeter] to the resistor [via brown wire from acc term], then to the coil .... if things are hooked up wrong, you can easily have 12V to the coil at all times, key on or not [or if the sw is bad]

there should be no continuity [ohms] from ign1 to ign2 with the switch off - if there is continuity from the batt terminal to acc terminal with key off, there will be power there [accessories run with key off], I forget now but think there shouldn't be .... there should only be power at ign1/2 when the starter is engaged

if it started with key off you may have continuity from ign1->2 all the time or have wires wrong there, or the acc term is hot all the time or the resistor wire is on the batt term .... confused yet?

Bill

OK, now that I am testing things correctly, There is no power to the coil OR the resistor bypass with the ignition switch turned off.

I think I fixed the problem before when I moved the red 14 GA. wire from an accessory terminal to its proper "BAT" terminal. This wire (based on my manual) runs through the ammeter and the light switch to the "B" terminal on the regulator.

There are still only two positions for the switch...

FWIW, the wire from the resistor bypass terminal on the starter runs up to the "start" terminal on the ignition switch. This is directly adjacent to the "IGN2" terminal that has a wire running to the resistor and another to the coil+ The other side of the resistor runs back to the "IGN1" terminal which has a wire running to the "IGN" terminal on the gas gage. These five wires are on a triple plug that only fits one way onto the ignition switch.

Hopefully when I get my carbs reinstalled, everything will be as it should be.

Thanks for answering while I was testing and composing my brilliant reply, Bill. I could have saved some time by just waiting for your post.

So, based on your answer, I think the heavy red wire that belongs on the "BATT" terminal being connected to an accessory terminal was the problem.

The diagram I am looking at is in the _1958 Chevrolet Truck Shop Manual_ There is a totally different diagram for a V8.

cool, sounds like ya got 'er figured, yes that heavy red wire is what needs to be switched on and off, certainly best not to have power to any acessories when yer in bed

I don't have a 58 manual, just 55 and 57, and a different diagram I found on the net that I think was 58-60 car, but all are really the same

Bill

We'll see if I really got it in a day or two. I'll leave the ground off the battery until then, anyway.

Thanks for all the help on this. I'm really just learning electrical stuff. I can follow wires on a diagram, but I don't know what everything does. I couldn't have done it without you all.

I'll post again in a day or two.

Jerry,

I'm glad things seem resolved. Was it ever discovered how the coil got full battery voltage during START. This would have to show up as a second wire on coil + or a second wire on the coil side of the ballast resistor. For a full voltage START the ballast resistor would somehow have to be bypassed, right.

Stuart

Stu - on the TF harness, both ends of the resistor connect to the switch, and the coil wire also comes from the switch [same terminal as output end of resistor], that's why I said when cranking the coil gets power from both the resistor and starter circuits .... prolly the "quick fix" GM used for introducing the resistor to an existing setup and still keying power to the coil ... why Jerry got suprised was he had the main hot wire hooked to the same terminal on the switch as the coil wire so it was energized all the time - lucky to not fry the coil!

Bill