Electrical - where to begin

[rockola1971]

you can pretty much test it yourself by starting it up turn everything on lights, hazard switch, heater full blast, radio, windshield wipers on full speed, defroster. and anything else
then take your meter and see how many volts are at the battery terminals, then also check at the alternator output, it should match what is being sent to the battery or be very close to the same should have no more than 1-2% difference

Yes. A true check Requires the alternator to be loaded down. You should see roughly between 13.8-15.0 vdc at the battery with engine running at idle and alternator loaded.

 

[Moosemoon]

Easy to remove alternator and take it to get bench tested. I believe most retail auto parts stores can do this for free. Not suggesting to get a replacement, yet. Hopefully the tester puts it on a scope or other device rather than just looking at voltage.

I take to one parts place today. They said they can test voltage and diodes while in the vehicle. Couldn’t get there today. Hoping tomorrow

 

[Moosemoon]

I take to one parts place today. They said they can test voltage and diodes while in the vehicle. Couldn’t get there today. Hoping tomorrow

Talked not ‘take’

 

[Moosemoon]

This has been a great thread so far. Lots of good info. What was/is the overall condition of your truck as far as corrosion goes? I can't think it would be too bad in ID, unless they do use salt out there.

My speculations are as follows:
1. Corrosion from elements over time. Also, corrosion from natural moisture, especially if it sat for 2 years outside, or on grass or gravel. Vehicles parked on non-solid surfaces are more prone to moisture related corrosion issues from my experience. I'd go over Chassis ground points with a wire brush, coat area with dielectric grease, and reassemble. Use a star washer if provided. Also check the main cables for discoloration and tightness of crimped areas.
2. Modules that died slowly from sitting so long. The steady decline can mess them up
. Or, a jump start from stone-cold dead as well. Have the battery load tested.
3. The alternator idea was something I didn't think of, but I would put down as a relevant idea. You could make sure the battery is fully charged, them remove the power wire from the alternator (tape it up, or put it in a non-conductive covering. Run the vehicle for a short time and see if anything changes. If you have a weak battery, this test won't work well.
4. Do a general inspection of wiring harnesses for pinched areas, worn areas, etc. Being that the trans and motor were gone through, it's a possibility something didn't get put together correctly. Look for proper routing near heat shields, mounting points, etc. Also look at connections to make sure they are in fact "clipped" together properly.

I absolutely HATE electrical gremlins. My hat is off to you for having the gumption to learn and tackle this yourself. Best of luck! Hopefully this brain trust (meant in sincerity) of a group can help you get it figured out. LOL

Thank you so much. I am learning tons. You have put alot of what is scattered in my various notes and brain in a good summary.

is there anyway to print this thread?

The Yukon has always been parked on firm ground but not garaged. Idaho has been using some sort of ’salt’ solution for the past 5 years or so. New DOT guy rumored to be getting rid of it! YAY. Give me crushed lava any day.

When I look under the Yukon, it looks reasonable to me. I used to wash the under carriage regularly in winter. But the last 2 winters it’s been in the guy’s shop. So I would say exposure to the salt experiment here has been minimal. That said it IS 22 years old. And from what I understand this generation is notorious for corrosion at critical points.

I would think the guy who did the work would have checked all that but based on all the other details that he didn’t address, I am pretty sure he did not do much.

Thanks again.

 

[Moosemoon]

you can pretty much test it yourself by starting it up turn everything on lights, hazard switch, heater full blast, radio, windshield wipers on full speed, defroster. and anything else
then take your meter and see how many volts are at the battery terminals, then also check at the alternator output, it should match what is being sent to the battery or be very close to the same should have no more than 1-2% difference

 

[Moosemoon]

In my opinion, if it were only a ground issue, there would be some consistency to the issues you are facing. There doesn't seem to be any. This leads me to believe it is a positive issue. Also, I have seen similar issues in four other vehicles, one of which was a Crown Victoria (the other three were a 2003 Sierra Denali, a 2004 Silverado 2500, and a 2005 Suburban 2500).

The idea of a ‘positive issue’ is interesting. Not sure I know how to go about testing that? Please forgive me, but I give new meaning to the word novice.
Thanks

 

[Moosemoon]

Ok I have a question.

would any of you allow the original guy to work on this again?

 

[B-train]

Probably not based on what I've read. It seems as though he's more of a body guy, not whole car guy. If he let it go out the door in a condition electrically worse than it arrived, he's not good enough at his job

 

[Doubeleive]

Ok I have a question.

would any of you allow the original guy to work on this again?

FOR 2 YEARS? absolutely not, shit for 2 years that thing better be like it just came off the show room floor

 

[Moosemoon]

Thanks that’s how I feel. Just needed confirmation.

BTW, he’s a horrible body guy. Granted it looks better than it did but it’s not even a decent paint job!

Thanks again!

 

[MassHoe04]

If I wasn't in a hurry, the most I would have waited might be a year at most...
And that would only have been if I had recommendations from other customers and had seen museum quality results.

Hindsight is 20/20, I know. But I am amazed you had the patience to hold on for 2 whole years.

At this point, I would not want the guy anywhere near the truck... That would be big "HELL NO!" vote for me.

 

[Moosemoon]

Probably not based on what I've read. It seems as though he's more of a body guy, not whole car guy. If he let it go out the door in a condition electrically worse than it arrived, he's not good enough at his job

If I wasn't in a hurry, the most I would have waited might be a year at most...
And that would only have been if I had recommendations from other customers and had seen museum quality results.

Hindsight is 20/20, I know. But I am amazed you had the patience to hold on for 2 whole years.

At this point, I would not want the guy anywhere near the truck... That would be big "HELL NO!" vote for me.

The first thing he did was take it TOTALLY apart. Nuts and bolts in little plastic container. I didn’t know how I could pick it up and even begin to hope I had all the pieces n parts.

 

[Moosemoon]

I tested all the fuses in box under the hood - 24 come up ‘short’. The big fuse for the A.I.R. system isn’t even there.

fuses that register as short have to do with everything lights, fuel, O2 sensors, instrument cluster and more. The PCM fuse tests normal.
The fuses are not blown. I did not test relays or do a ‘see-if-it-works‘ for the part corresponding to the shorted fuse. There was weather moving in.

i purchased an ECT3000 and i think i am using it correctly. i am supposed to be able to follow the short with it but didn’t try that yet. not really sure where to begin with that.

I hope tomorrow morning to take the fuse box off and check to make sure what’s plugged into the PCM is indeed plugged in.

Oh - I did find a - what appears to be - comprehensive chart of all the grounds. Should I check all of those?

Am I on the right track or should I be doing something else? Thanks to you all!

 

[Moosemoon]

Went back out after weather threat and did a check of the items that we could. The only things that really didn’t work were the R puddle lamp and the rear parking lamps.
Everything else we could test worked fine.

Going to test fuses in the other 2 boxes now.

 

[Moosemoon]

Couldn’t find third box under dash - until a couple weeks didn’t even know there was one. Getting cold so came back in.
Anyway, almost all tested short in the side box, 1 did not register at all - that was for the starting system. Only 8 were ok.
This is all making me very nervous.

 

[Doubeleive]

Couldn’t find third box under dash - until a couple weeks didn’t even know there was one. Getting cold so came back in.
Anyway, almost all tested short in the side box, 1 did not register at all - that was for the starting system. Only 8 were ok.
This is all making me very nervous.

what do you mean by tested "short"? some fuses have constant power and some only have power when the vehicle is on or when the particular option is being used.

 

[Moosemoon]

what do you mean by tested "short"? some fuses have constant power and some only have power when the vehicle is on or when the particular option is being used.

Yeah- I think that I didn’t do this right. So, will try again tomorrow. This is all new to me. Thanks for confirming my error.

 

[Baja_Bob]

When you refer to "short", are you testing each fuse with one of the test leads on each side of the fuse terminal and the other test lead to the battery ground terminal?

Fuses shouldn't have a direct path to ground, they're meant to protect circuits against overload and dead shorts.

What tester do you have and what setting are you using?

 

[Baja_Bob]

Did you say you had or could get a wiring diagram? This might be needed to identify what components have a body ground. I don't know how far the guy disassembled and what was painted, interior and exterior or just exterior, but he could have reattached a ground to a painted-over stud or threaded hole.

I'm just trying to get a better picture of what's going on.

 

[Moosemoon]

Did you say you had or could get a wiring diagram? This might be needed to identify what components have a body ground. I don't know how far the guy disassembled and what was painted, interior and exterior or just exterior, but he could have reattached a ground to a painted-over stud or threaded hole.

I'm just trying to get a better picture of what's going on.

Thanks. I am using Power Probe ECT 3000. I have a DMM as well.
However - the ‘shorts’ are totally my user error
Going to try again later today.