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-   -   wiring smoking! (https://67-72chevytrucks.com/vboard/showthread.php?t=376060)

alden 12-12-2009 10:28 AM

wiring smoking!
 
I thought I had the wiring figured out so I decided to hook up the battery and test lights etc, but when I did that all of a sudden my wiring started smoking and crackling.

I don't have the headlight switch or the lights hooked up but didn't think that would be a problem. I didn't even get around to turning the key, it just started crackling immediately so I unhooked it before I started a fire. What could I have possibly done so wrong?

truckdude239 12-12-2009 10:34 AM

Re: wiring smoking!
 
you have a sort somewhere

alden 12-12-2009 10:42 AM

Re: wiring smoking!
 
but it's all brand new wiring. Is that normal? I seriously mean everything was crackling and smoking. The wiring to the starter was smoking and the wiring to the cluster was smoking.

Twisted Elegance 12-12-2009 11:20 AM

Re: wiring smoking!
 
there is a direct short some where in you wiring. you need to go over every wire and make sure that you don't have a power wire hooked to a groung source. more than likely you did cause some damage to your wiring, so go over all the wires to look for bare spots.

dwcsr 12-12-2009 12:16 PM

Re: wiring smoking!
 
Your question is sort of like asking what raindrop got my car wet. Without actually seeing how it was rewired only you can answer that questions.

Give us some basic information

12 volt or 6 volt chevy or GMC? Generator or Alternator?

You say its all new wiring, Is it a kit or did someone replace wires?

You have a dead short somewhere.
Possibilities are
1. Reverse a ground somewhere
2. Positive wire bare and touching ground.
3. Wrong polarity on the battery.

A word of caution... its never a good idea to test electrical wiring until you have all the components connected or isolated.

Chances are that your wiring needs to be redone now that you let the smoke out of it.

alden 12-12-2009 12:35 PM

Re: wiring smoking!
 
Chances are that your wiring needs to be redone now that you let the smoke out of it.

I was afraid of that.

I swapped the wires on the starter (Starter motor resistor terminal to ballast resistor/Coil "BAT" terminal to starter motor resistor terminal swapped with the Starter motor "switch" terminal to neutral safety switch) and now if I hook the battery up there is no smoking, no crackling etc. I'm hoping all that was damaged was the outer wrap on the wires but I don't know for sure.\

oh, it's a 59 chevy 235, generator and the wiring is a kit from brothers (factory replacement).

JML55 12-12-2009 02:15 PM

Re: wiring smoking!
 
Before your final hook up to the battery place your test light between the battery negative terminal and ground wire if the test light comes on there is a short somewhere.

alden 12-12-2009 02:24 PM

Re: wiring smoking!
 
Quote:

Originally Posted by JML55 (Post 3671047)
Before your final hook up to the battery place your test light between the battery negative terminal and ground wire if the test light comes on there is a short somewhere.


I have a multimeter, can I just use that? If so what should I be touching it to?

dwcsr 12-12-2009 03:25 PM

Re: wiring smoking!
 
Your going to have to inspect the wiring carefully. If the outer wrap is melted then it has affected the integrity of the insulation. If its only the wires to the starter and balast you could just replace them. The balast will make a crackle noise when shorted out.
Did you get smoke in the cab?

63 & 64 Bowties 12-12-2009 03:29 PM

Re: wiring smoking!
 
Quote:

Originally Posted by alden (Post 3671055)
I have a multimeter, can I just use that? If so what should I be touching it to?

That would work even better. Set it to DC volts (low range) and if you've get a negative voltage somewhere, you've found your problem.
Good luck. Let us know how it turns out.

alden 12-12-2009 04:08 PM

Re: wiring smoking!
 
Quote:

Originally Posted by dwcsr (Post 3671136)
Your going to have to inspect the wiring carefully. If the outer wrap is melted then it has affected the integrity of the insulation. If its only the wires to the starter and balast you could just replace them. The balast will make a crackle noise when shorted out.
Did you get smoke in the cab?

Do I just touch the positive to a wire and the negative to a ground to see what return I get?

I had some smoke near the gauge cluster as well. When I swapped the wires on the starter all the crackling/smoking ceased so I think that may have been my problem (basically it boils down to me knowing nothing about what I'm doing). I took a look at all the wires that had been smoking and none of the wire insulation seemed penetrated or burnt (the little electrical tape style wire wrap that was holding the bundles together was dried up though).

I had to call it a day, it's too cold and I'm too impatient to be working on it right now, I have the feeling I'd just screw things up more. As of right now the only things left to wire up are as follows:

Ignition ballast resistor
Headlight Switch
Gas Tank sending unit

On that note, does anyone have a diagram for the headlight switch? Mine has 6 connections, and I have 6 wires, but I know I also need to put a ground on it to ground it to the firewall.

Also, my truck had a fuse block in it already but it was only used for the radio. Since I don't have the heater hooked up or a radio in it, should there be anything connected to the fuse block?

Today was just one of those days that I managed to just screw up everything I touched. On a positive note I do have turn signals now, which is something that was not functioning before so I guess I'm 1 step forward, 5 steps back :lol:

63 & 64 Bowties 12-12-2009 04:15 PM

Re: wiring smoking!
 
does this help you at all?
http://i117.photobucket.com/albums/o...dcabwiring.jpg

alden 12-12-2009 04:39 PM

Re: wiring smoking!
 
thanks. Apparently the problem is that my switch was not original. Looking at the one sold by brothers and back at the assembly manual mine is not the same (and has fewer connections) so I'll just order one and get the right thing in.

mr48chev 12-12-2009 05:51 PM

Re: wiring smoking!
 
That may be it but I am with Twisted Elegance in that I believe you have either a direct short or that you have one of the wires hooked directly to ground instead of where it should go.

Find the wire that got hot and follow it to see where it goes and that it isn't shorted out somewhere. Since it appears that the problem started with the switch trace each wire from it to make sure that you don't have wires going to the wrong thing.
You can pick up a good quality test light at most parts houses or Sears and I'd suggest getting one as it is a lot easier to use when you are upside down and backwards under the dash. Just make sure that you do check to make sure it is working right every time you use it. Some times what looks like it should be a good ground isn't a good ground and I know that from experience.

alden 12-12-2009 05:58 PM

Re: wiring smoking!
 
Quote:

Originally Posted by mr48chev (Post 3671396)
That may be it but I am with Twisted Elegance in that I believe you have either a direct short or that you have one of the wires hooked directly to ground instead of where it should go.

Find the wire that got hot and follow it to see where it goes and that it isn't shorted out somewhere. Since it appears that the problem started with the switch trace each wire from it to make sure that you don't have wires going to the wrong thing.
You can pick up a good quality test light at most parts houses or Sears and I'd suggest getting one as it is a lot easier to use when you are upside down and backwards under the dash. Just make sure that you do check to make sure it is working right every time you use it. Some times what looks like it should be a good ground isn't a good ground and I know that from experience.

I guess i should have clarified earlier. My truck doesn't have a factory starter switch, it has the type of starter from the late 50's cars that either used a push button or just the key, so there was no switch that was miswired, just the starter itself.

OrrieG 12-14-2009 04:34 PM

Re: wiring smoking!
 
I sent you a couple of PM's

mylow53 12-15-2009 02:04 PM

Re: wiring smoking!
 
the safest way to check for a short is to connect a volt meter between the positive battery post and the disconnected positive battery cable it should read 12 volts. then begin disconnecting all the fuses see if one makes the voltage drop. (since this is smoking the wires this probably wont effect it) then begin disconnecting all of your major wires starting at the starter. then the amp meter then the gen/alt if that won't drop the voltage start wiggling your harness where ever it can be pinched, or passes thru metal. eventually you will find it. when you do just replace that wire and anything that has exposed copper from a burn. all of your other wires should be fine so long as they weren't over heated
GT

50adrod 12-15-2009 03:29 PM

Re: wiring smoking!
 
Quote:

Originally Posted by alden (Post 3671213)
Do I just touch the positive to a wire and the negative to a ground to see what return I get?

I had some smoke near the gauge cluster as well. When I swapped the wires on the starter all the crackling/smoking ceased so I think that may have been my problem (basically it boils down to me knowing nothing about what I'm doing). I took a look at all the wires that had been smoking and none of the wire insulation seemed penetrated or burnt (the little electrical tape style wire wrap that was holding the bundles together was dried up though).

I had to call it a day, it's too cold and I'm too impatient to be working on it right now, I have the feeling I'd just screw things up more. As of right now the only things left to wire up are as follows:

being impatient and not knowing what you are doing is not a combination you want when wiring a truck. step back and study the wiring diagrams then proceed, if you are confused get help or have somone qualified wire it. It would suck to see your finshed truck go up in smoke. hope you get it figured out soon.

iroc12valve 08-12-2010 02:56 PM

Re: wiring smoking!
 
It might sound funny but when i got my crew cab i was tired and when i went to hook up the battery i looked at the terminals, saw a black one and a nother one thought nothing of it put black to ground on the battery and other to positive, well it instantly sparked so i pulled it, and went to bed. next morning i see that the ground is mounted to the motor mount and that the black was the positive i hooked them up as such and never had a problem since. long story short check the odvios first

start with the battery and then check the cables/wires starting with the larger ones first. the larger the wire the more damage it does when it hits ground

alden 08-12-2010 03:13 PM

Re: wiring smoking!
 
sorry I think I followed this up in a new thread later on. The company that made the harness repaired it for me and it's in and working fine now. I'm still not 100% sure what I did wrong but the assumption is that I had something backwards on the regulator.

stsalvage 08-12-2010 03:38 PM

Re: wiring smoking!
 
I have a 1965 3/4 ton truck with a 350 and a 2 speed power glide i'm in the junking business I was come home from hauling a load and i was almost at my exit and the truck started smoking in side.I don't smoke and the truck never smoked before i was doing 70 in the fast lane and it got very foggy in side that cab my Gand father told me once if that ever happens tun off the key switch and leave it in drive that will stop the fire and just pray it will fire up again when you turn the key It did but one hell of a back fire i got it home and when i turned it off in the drive way it did not start again So that next week went to the classic truck shop Bought the all new Repo factory harness for 395.00 that's with the fuse panel and all the wiring harness From M&H and it had all the factory plugs had it in in 2 hours and that truck has never had a problem sence and that was 7 years ago One hell of a investment

alden 08-12-2010 04:20 PM

Re: wiring smoking!
 
yeah M&H really took care of me. Repaired the wiring at no cost to me, only asked for me to pay for it to be shipped - great group of people.

bobinbc 08-13-2010 03:24 AM

Re: wiring smoking!
 
Pardon my ignorance but who is M&H ? Do they have a website?

Also a tip I heard when testing wiring is to use a 2 amp trickle charger or a flashlight battery for power. Same voltage but low current.

alden 08-13-2010 04:25 AM

Re: wiring smoking!
 
Quote:

Originally Posted by bobinbc (Post 4136733)
Pardon my ignorance but who is M&H ? Do they have a website?

Also a tip I heard when testing wiring is to use a 2 amp trickle charger or a flashlight battery for power. Same voltage but low current.

No problem - http://www.wiringharness.com/

Brotherstrucks.com sells their harnesses (the factory reproduction ones they sell), that's how I found out about them.

dewey777 08-13-2010 03:27 PM

Re: wiring smoking!
 
Should always hook up to a low current battery charger first to check everything as well. That way if there is an issue you don't smoke something (or everything!). The analogue meter on the charger will pin if there is a large draw or a short without smoking anything.


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