The Stovebolt Site Forums The Shop Area The Electrical Bay 1965 C10 - alternator or battery...

1965 chevrolet c10 lwb

1992 5.7L/350 engine with 1992 doodads, but with a carb..

The low down...

So, I'm riding in big blue today on the way to school and I noticed that my blinkers are not flashing as fast as usual. I'm thinking,

"hmnn, ok blown bulb prolly, no biggie."

I check the flashing action all around and each one was flashing.... "hmmmn."

Went to class, came back out... fired up the truck...

Rolling down the highway to the house...

'hey my wipers are awful slow.... hey my blinkers are still slow.... hey when I turn my heater on the radio cuts off...'

I make it to the house, I don't shut the engine off... I put volt meter on the posts... 9.79 volts with it running.

That ain't good..!

So, I shut it off and check it again... same, 9.79 volts.

I went inside, rapped with my dad about it, we went out and checked it again... it went up to 10.0 volts or so.

Of course... wouldn't start....

battery is new from last year's starter fiasco(I think that was last year anyway).


I've never replaced the alternator since I bought it in 2003, so I'm guessing that is the issue.

Tho', I guess it could be the battery, but I'll stick it on the charger to see if it'll hold a charge.

Anyway, I'm open to anything else to double check... thought I'd run it by ya'll.

Take care,

-W

p.s. I'm asking everybody, everything:

thread on chevytalk

thread on 67-72 site / 60-66 section

Jump start it, put the volt meter on the battery and rev the motor. Even if your battery dropped a cell you should see a jump in voltage when you rev the motor. If not, your alt took a dump or you have a loose/broken wire.
Nice thing is either part can be double checked at a FLAPS to be sure. Good luck, hope it's just a loose wire.

Definitely something wrong with the charging system.

I agree. Should have had more voltage, around 13.5-14.5 running, regardless of the charge state of the battery. Good chance the battery has been damaged internally, it'll need recharged and you should have it tested once you take care of the alternator issue.

Charge the battery overnight at a 10 amp rate or so, and if possible, check the specific gravity of the acid in the morning. It should be between 1.265 and 1.300 or so on all cells, with no more than a 20 point variation or so. Open-circuit voltage on a fully-charged battery shouls be 12.6 volts or slightly more. If you don't have access to a high-load tester for checking cranking power, disable the ignition and crank the engine for 15 seconds. Battery terminal voltage at the end of the cranking session should be 10 volts or more, while the engine is still cranking. If the battery passes all these tests, replace the alternator, after checking to be sure the charging system wiring is in good shape, of course.

Jerry

Chances are it has an external regulator. If so pull the connector off the reg. & hook a hot wire to the blue/field wire at the connector. You should get a little blue spark when you touch it. Start it up & it should charge way over. If not the alt is bad. If it does then the problem is in the regulator. This is providing the wireing is good.

Well, I charged up the battery last night and I was checking the voltage with a meter...

... I don't think a alternator works so good with a burnt wire:

burnt wire


Now I'm wondering how this happened to start with.

I hope to get out there tomorrow and tear into it, but I thought I'd keep you guys in the loop.

Thanks for all of the replies folks.

-W

p.s. my alternator, power steering pump, water pump, etc.. are all similar to the 1992 engine accessories

There looks to be a bit of green corrosion on that wire, am I correct? That much doesn't build up so fast. Could have been a cut in the insulation and as the corrosion degraded the metal it got to the point the wire was too thin & finaly let go under load.
One possibility anyway. Usualy, other than a section of fusable link, if a wire gets hot enough to burn out more of the insulation is burned up than that one section shown there.

It looks like there's been some shade-tree splicing done right there. Resistance at a splice is a heat source, and the higher the current flow. the higher the heat becomes. Eventually, the insulation melts, the wires corrode, and the joint burns in two. On any main charge lead connections, I'd reccomend either using a single wire without splices, or doing a soldered joint if it's absolutely necessary to connect wires together. I'm partial to the "Western Union splice" that was used on telegraph wires for decades. Strip about 2 inches of insulation off each wire, criscross them at the midpoint of the bare spots, and do a tight wrap in both directions with pliers so there is a very wide point of contact. This makes a splice with virtually no resistance, plus it's so strong the wires will break somewhere other than the splice if subjected to a hard pull. Then solder the joint together with rosin-core solder and cover it with a piece of heat-shrink tubing for a neat-looking, permanent repair.
Jerry

Jerry gave a good description of the "Western Union splice" that I thought only old telephone and teletype techs knew how to make. Like he says, it is actually stronger than the original wire once soldered and the finished splice is only slightly larger than the original wire diameter.

Waldo, when you've strung and repaired as many miles of barbed-wire fence as I have, learning to make quick, strong splices is an absolute necessity! Nothing like trying to get that last notch pulled on a ratcheting fence-wire stretcher and having a splice let go, that will remind you to do it better next time! Those splices aren't soldered, either!
Jerry

Update on my '65 electrical drama:


so, I finally got out there to pull the alternator off and of course, it started raining.

figures.

disconnected the battery, went to undo the other plugged in wires on the alt. and it broke off in my hand.

oops.

took bolts out, alternator off... all in record time!

So, then to the marathon parts search at the store...

first off, a alternator bench check... F A I L(big white letters in a red box on the screen). I figured it was toast, but it's best to be sure, right?


It's not a '92 alternator(tho' it is a '92 engine with a carb. in a '65 truck)... parts number cross check brought up an air filter!? hah! This is gonna be fun...


So, old crusty black dude at the O'Reilly's parts counter kept at it... not a '89, not an '85, not a '75, not a '72.... 'could it be for a 307?' we don't know....

He went back to '69 c10 with a 350 and brought up the picture.... perfect match. en heche mexico alternator... hmmn.

Of course tho', they don't have the snazzy now fried out snap in plug, so off to NAPA... their warehouse of course, has 9 of them... so, maybe they will have it Monday. I can make my own plug using connectors, of course. I will abstain from the redneck engineering for now tho', hopefully.

It's supposed to flood here the next 2-3 days anyway... so, the no plug situation works out for me.

Now, I still have to trace the wires back and see if there is further damage, etc..

Old trucks are fun!

Especially when they are broke in the cold and rain!

Ya'll have a good weekend!


Thanks again for all of the replies fellas. It is nice to have ya'll around.


-W

It seems NAPA has the voltage regulators in the system... at least one for a '65. American Classic has one in the catalog on their site.

Were there any big changes or differences in the voltage regulators, year to year? Things that I need to be aware of?

I'm guessing with all that has happened so far the regulator is smoked as well.

It's 37 degrees F and raining outside, so I haven't been motivated to go catch a cold yet.

-W

If you have a 63-72 alt. that uses the external reg. any one in that era will work. I would put the alt on & make sure the wireing is right. The reg. on it may be all right. If you put it on & it still doesn't charge you can check it like I described earlier. When it's all done & working you should put a voltmeter on it & make sure it charges between 13.8 & 14.5 volts.

Thank you for that information Wrenchbender Ret..

Thanks again to everyone else who has replied as well.

I will keep ya'll apprised.

-W

I wired everything up and installed the new alternator... checked continuity between the new wires and the voltage regulator / battery, etc..

It is still not charging.

Will not run without the battery.

So... my guess is that the voltage regulator is not right, the new alternator is no good... or there is still something off in my 44 year old wiring harness.

Bah.


-W

With the connector off the regulator energize the blue wire going to field on the alt. It should charge infinitly if every thing else is good. If it does then the reg. is bad.

Hi Wrenchbender,

I read your earlier post about that, but I was not sure I fully understood.

1) disconnect the plug/connector at the voltage regulator(black plug, 4 wires, plugs into the side)

2) run a positive hot wire to the blue wire going to the alternator.

3) start the truck

4) Check for over charging with a voltmeter.

5) if overcharging, replace voltage regulator (see shop manual for details)


I just want to make sure I understand you before I fry what's left of my electrical system.

Thanks a bunch,

-W

You got it. There is a hot wire on the connector to the reg. You can jump it over to the field wire with a short jumper. When you touch it & break it you will get a little blue spark. That will indicate the field circuit in the alt is good. When you run it turn off the radio & any electronic devises. Don't let the voltage go over 15 volts.

So, I went to run the test that Wrenchbender prescribed and the truck wouldn't start!!!

*&^&!(!!!!

I had to sit quietly for awhile... and calm myself.

Then, I snatched out the engine module and had it tested... fail.

(which, another funny... a 1965 truck with a 1992 350 engine block with a 1969 alternator... and a 1974-1987 hei engine module... whew, it is good that I write this stuff down)

After all of that drama and reinstalling... truck runs, yay.

I did the test with the jumped wire on the connector... it was running about 14+ volts.

O.K., so... now, the alternator works... whew.

Then, off with the voltage regulator and dropping the nuts and washers down in the body... and strangely enough, shock of all shocks... NAPA had one on the shelf. Whoa!

I had run out of ambition for one day tho' and decided to call it dinner time.

I hope to install the voltage regulator, later today, weather permitting.

Another question... I currently do not have a specific ground wire running to the back of the alternator... the the ground wire post on the back there. I was thinking of running one from the ground wire post on the alternator to the negative battery cable terminal. Is this a good idea or is there a better location? Is the ground wire necessary? The last one didn't have one(it was like that when I bought it, I never noticed the post).

Thanks folks...

Special thanks to Wrenchbender for the testing method information!


-W

While a ground wire might not be absolutely necessary, it's still a good idea. The regulator base has rubber grommets for vibration isolation, not electrical insulation. I'd suggest running a moderate-sized ground wire (#14 or so) from the regulator housing to the engine block somewhere- - - -it doesn't necessarily have to go all the way to the alternator. That assures that rusty body mounts, missing engine-to-frame ground straps, etc. don't insert any resistance in the circuit between the alternator and the regulator. BTW- - - - -trying to keep the engine running with a battery cable disconnected does things to sensitive electronics- - - -like killing an ignition module. Just as the circuit is broken, voltage spikes can go as high as 100 volts or more, and solid state electronics really hate voltage spikes!
Jerry

Edit: If the negative battery cable is attached to the engine block, like it should be for a good starter circuit, another ground for the alternator/battery circuit isn't required. If the negative cable grounds to the frame, you need a BIG ground from the engine to the frame, a #4 cable or bigger.
Jerry

HotRod Lincoln,

my negative battery cable runs to the frame and I have a separate battery cable that runs from the engine block to the frame on the other side. I added block to frame cable after I bought it.

Thanks for the tips.

It is raining cats & dogs here, so maybe I can get to it tomorrow.

-W

victory is mine!!!

It starts, it charges, it runs!

YAY!

Thanks a bunch to everyone for all of the replies, advice and tips.

I got the voltage regulator in today, after much cussin' and talking bad with trying to put the nuts on those 3 bolts... that was the most aggravatin' part of the job.

I ran a ground from the ground post on the alt as well, to be sure.

After putting up the tools and so forth, I took a ride around the county in it and filled up with gas. The moment of truth was when it cranked after the fill up.

Yay!

It's so nice to drive my beat up old truck again.

Thanks everyone!

-W

pics of the fried wiring & the new stuff installed



-W

Well folks, I was checking my transmission fluid today and I noticed that the wires on the alternator side had fried again.

dad gummit.

I wired it all back up and checked it, seems everything is working again.

I am going to replace the harness part that runs from the voltage regulator to the alternator and a few other places as it seems rather toasted and brittle.

Any ideas on anything else I should check?

I'm not sure why it did this, again.

Hmnn...

-W

photos - new url

lots of great information in this thread folks.

thanks again.

I've pointed a lot of people in the past few years to this thread for troubleshooting tips.

Take care,

-W