Update on electrical short - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**Yukon Jack** · 10-26-2002, 09:17 PM

Wasn't able to make it out the last few nights to try to figure out what the short was but did have a few minutes this afternoon to take a look under the hood. First thing I noticed was the battery cable from the remote selenoid to the starter was resting on the frame. Moved it and saw that the frame had worn into the covering to the wires. Sweet, easy fix. As the engine is coming out in a couple days I just get a plastic wire cover and slip it over the wire then replace the fusibile link. Hit the light switch and they light right up. Crank the truck over a few times (takes a few times in the cold with no choke) and get it going. About 20-30 seconds later, I see tons of smoke coming from near the battery. Pull the keys out, jump out and see the fusible link and some other wires bright red and smoking big time. Then I see the wires on the alternator smoking. Great. Start wondering why I've never been smart enough to get the fire extensgisher in the barn.

Thankfully, the smoldering stops, barn stinks to high heavean. Start to look to see what happened and see that the wire the fusible link is hooked to is wasted to the black block on the fender. Then the red wire going in front of the radiator is toasted all the way to the altenator. Where it connects to the alternator the bolt is very loose as if something inside burned or melted.

I have no idea what went wrong, but I guess I will be doing some re-wiring.

Is it likely that the altenator is toast. Doesn't matter as it is being replaced. But what I'm worried about is what cause this to happen. Don't want it to happen when the other engine is in.

Talk about feeling proud of yourself and then scratching your head in disgust in a matter of seconds. Bummer

Blue_71 · 10-27-2002, 12:45 AM

same thign happened to me when i first wired my 4x4, never did figure out whathappened to that stupid thing.. put a different harness on it and havent had any trouble sinse except my lights dont work (never have, no wiring in the back and no bulbs in the front markers, and the tabs are broke off the headlights

)

barn9 · 10-27-2002, 10:25 AM

Hey Mark, sounds like you're changing engines at the right time, hehe! Are you still running through the voltage regulator? If so, I would say this is the time to change to the internally regulated alternator. Give me a call if I can help, LB.

**Yukon Jack** · 10-27-2002, 12:53 PM

I will be using the altenator on the 454 - just don't want to fry it if this problem is still around!

**68 Stepside** · 10-27-2002, 01:12 PM

Man...

I'll tell you what, since your beast is being such a pain, why don't you just load it, and the 454 up, and just bring them to me? I'll take them off your hands, so you don't have to hassle with them anymore.

Now, on to helping you out:

If it were me, and I was changing engines anyway, I'd talk to a member, and just buy a good used, uncut engine compartment harness. It would be cake to change, with the engine out. Then you could start fresh, it's better than having a butchered wiring harness. Been there, done that, too many times....

Best of luck!

TJ

chewed 71'er · 10-27-2002, 02:05 PM

Yukon, make sure the wiring you install is compatable with the amperage output of the 454 alternator. The 454 alt. may produce more amps than the trucks original, and you'll need heavier wiring. Don't want to toast anymore harnesses, or a fresh engine. I'm sure there are plenty of guys on the board that can give more details.

10-26-2002, 09:17 PM	#1
Yukon Jack Post Whore Join Date: Feb 2000 Location: Rose Hill, KS, USA Posts: 12,686	Update on electrical short Wasn't able to make it out the last few nights to try to figure out what the short was but did have a few minutes this afternoon to take a look under the hood. First thing I noticed was the battery cable from the remote selenoid to the starter was resting on the frame. Moved it and saw that the frame had worn into the covering to the wires. Sweet, easy fix. As the engine is coming out in a couple days I just get a plastic wire cover and slip it over the wire then replace the fusibile link. Hit the light switch and they light right up. Crank the truck over a few times (takes a few times in the cold with no choke) and get it going. About 20-30 seconds later, I see tons of smoke coming from near the battery. Pull the keys out, jump out and see the fusible link and some other wires bright red and smoking big time. Then I see the wires on the alternator smoking. Great. Start wondering why I've never been smart enough to get the fire extensgisher in the barn. Thankfully, the smoldering stops, barn stinks to high heavean. Start to look to see what happened and see that the wire the fusible link is hooked to is wasted to the black block on the fender. Then the red wire going in front of the radiator is toasted all the way to the altenator. Where it connects to the alternator the bolt is very loose as if something inside burned or melted. I have no idea what went wrong, but I guess I will be doing some re-wiring. Is it likely that the altenator is toast. Doesn't matter as it is being replaced. But what I'm worried about is what cause this to happen. Don't want it to happen when the other engine is in. Talk about feeling proud of yourself and then scratching your head in disgust in a matter of seconds. Bummer __________________ 1970 Blazer with a 400 sbc and 4" lift 1980 Pontiac Trans Am, 455 Oldsmobile 2012 Kawasaki Concours 14

10-27-2002, 10:25 AM	#3
barn9 Half a bubble off! Join Date: Jun 2000 Location: Winfield, Ks, USA Posts: 5,588	Hey Mark, sounds like you're changing engines at the right time, hehe! Are you still running through the voltage regulator? If so, I would say this is the time to change to the internally regulated alternator. Give me a call if I can help, LB. __________________ Just call me LB. '71 Cheyenne, 402BB, hauls blondes, brunettes, or redheads.

10-27-2002, 12:53 PM	#4
Yukon Jack Post Whore Join Date: Feb 2000 Location: Rose Hill, KS, USA Posts: 12,686	I will be using the altenator on the 454 - just don't want to fry it if this problem is still around! __________________ 1970 Blazer with a 400 sbc and 4" lift 1980 Pontiac Trans Am, 455 Oldsmobile 2012 Kawasaki Concours 14

10-27-2002, 01:12 PM	#5
68 Stepside huh? Join Date: May 2000 Location: Washington, Illinois Posts: 5,690	Man... I'll tell you what, since your beast is being such a pain, why don't you just load it, and the 454 up, and just bring them to me? I'll take them off your hands, so you don't have to hassle with them anymore. Now, on to helping you out: If it were me, and I was changing engines anyway, I'd talk to a member, and just buy a good used, uncut engine compartment harness. It would be cake to change, with the engine out. Then you could start fresh, it's better than having a butchered wiring harness. Been there, done that, too many times.... Best of luck! TJ __________________ Someday when I'm lonely, Wishing you weren't so far away, Then I will remember Things we said today. RIP El Jay

10-27-2002, 02:05 PM	#6
chewed 71'er Registered User Join Date: Mar 2002 Location: KC, NW Missouri Posts: 144	Yukon, make sure the wiring you install is compatable with the amperage output of the 454 alternator. The 454 alt. may produce more amps than the trucks original, and you'll need heavier wiring. Don't want to toast anymore harnesses, or a fresh engine. I'm sure there are plenty of guys on the board that can give more details.



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