I'm creating more problems than I'm fixing.

[tc197]

87 GMC V2500 TBI 5.7 SM465 NP208

I'm beyond frustrated with my truck right now. I've blown more hours than I want to count trying to fix a problem that didn't exist until I caused it.

Everything started a month ago. My trans was leaking so I decided to replace it. Truck ran great otherwise, no issues, just didn't want to leave puddles everywhere I went. Dropped the trans and tcase, replaced the pilot bearing, clutch, flywheel, throwout bearing, and swapped the new trans in. Took me an entire labor day weekend by myself as I've never done anything like this before. Got everything in and went to roll the truck off the ramps in my driveway and I didn't have brakes. No big deal, quickly saw I had crushed a brake vacuum line, a few hours later I had brakes again.

Everything was going fantastic. I had actually swapped the trans in successfully. It shifted and drove great, it started right up, life was good. Before going to leave for the night I decided to do a walk around and make sure I hadn't forgotten anything. Truck was running, I pulled the headlight switch on and bam - instant dead. Truck lost all power to everything. I shut the headlight off, tried to restart the truck, and it fired up and immediately died. From here on out I've had nothing but problems.

First I checked all my fuses near the e-brake, nothing was blown.

Checked the fusible links after reading about them here, saw one was cracked open so i replaced it, still nothing.

Pulled all the grounds I could find, resanded the contact points, and rebolted them all down. Still nothing.

Replaced the headlight switch. Nothing.

I had a spare steering column because mine was busted up and decided I'll just swap that in and see if that helps anything. Got everything apart, had rust holes breaking open in the firewall because it had clearly never been taken out before, got the new column in, now I can't even get it to crank.

Played around for a few hours trying to see if I did something wrong, gave up, and put the old steering column back in. Cranks again - still no start - headlight kills all.

Saw I hadn't cleaned the ground from the alternator to the alternator bracket so I pulled it and cleaned it. Went to start the truck and now I don't even get a click. Battery reads 12.7 on the charger with no load, I have power to the starter. I have power to the alternator. I'm at a complete loss.

Some how in cleaning that ground I moved backwards in progress and now I can't even get my truck to crank. The wiring harness has been hacked to shoot, I have disconnected plugs all over (all were disconnected pre-trans swap as well by previous owner) and I don't know what to do or where to start. When I turn the key I get blinkers, heat/ac blower, hazards, wipers but nothing else. I don't here the fuel pump click, I don't get radio, when I try to start it I don't get anything at all. Headlights still don't work. All I wanted to do was stop my transmission from leaking and now I have a truck in pieces that I can't drive and I can't figure out what the problem(s) are. Any advice?

[hatzie]

Something blew out that fusible link. 
I didn't see mention of finding the culprit.  Find the reason the fusible link blew out before you go any further.

Since this happened after a transmission swap I'd check the 10ga wires down the bellhousing to the starter and make sure you didn't pinch them. 

[tc197]

Thank you I'll check into that. Also the fusible link still had continuity across it, just the plastic box itself was cracked open. Not sure if that meant the link was toast or not so I replaced it anyways.

[80Chevy4x4]

Welcome to our wonderful world of Truck Modifications......LOL    you are passing the test 

[VileZambonie]

I agree with Hatzie, you probably pinched a wire. Check carefully between the back of the engine and the trans. Repair and then replace your fusible links.

[tc197]

Unfortunately I'm away from the truck during the week so I won't get a chance to try this stuff until the weekend. I was reading another thread that mentioned making sure the alternator hadn't seized so I'll check that too.

My plan so far:
1. Make sure alternator isn't frozen
2. Pull starter and check fusible link/for pinched wires (I could see/feel the wires running down to the starter and didn't notice any still pinched but it's possible something got squished and didn't stay squished)
3. I was reading about a ground that's supposed go to the back of the motor? I definitely haven't found that ground yet - so far I've cleaned up the battery to the frame, the battery to the front sheet metal, the alternator bracket, the left headlight to the front sheet metal, and I have continuity between all of these grounds back to the negative terminal of the battery.

The thing that started all of this (back when it still cranked over) was pulling the headlight switch and I've yet to solve that problem. I appreciate the help guys!

[tc197]

Update from today:

Started the day off by making sure the alternator spins, it does and is nice and tight so all seems good there. Next I pulled the starter and jumped with my battery. Starter is good. From here I knew something between the steering column and starter was an issue. I checked the fusible links and all of the wires around the starter. The fusible link looked good and had continuity, all of the wiring looked good. Nothing was crushed, nothing was stuck in the bellhousing, etc. I checked all my fuses and as a last ditch effort ran to the parts store and bought a new ignition switch. Installed the ignition switch and now it cranks over. Somehow in trying to fix my initial problem, I fried my ignition switch.

Now I'm back to the beginning. The truck cranks over but does not start. The blinkers, brake light, wipers, blower, all work fine. The headlights do not work and the check engine light is not coming on prior to trying to start it. I can visually see fuel spraying when it is cranking with the air filter removed. Everything started going downhill after swapping the transmission and then turning the headlights on. From this point forward the truck hasn't run the same. What am I missing that somehow links my headlights to the truck not starting/running properly?

[80Chevy4x4]

I can't remember the exact way your engine compartment looks,but a quick thing to check is to make sure the distributor cap did not get cracked or has been kicked sideways a hair...i know a lot of problems when replacing a transmission is the distributor hit the back firewall when the engine was lowered.....this might help...check for spark.

[tc197]

Thanks for the tip. I don't see any cracks and what makes all of this extremely confusing is that it will start and immediately die. I'm having trouble explaining what exactly is happening so let me try again.

Headlights don't work period.
Key on - no dash lights.
Crank for 2-3 seconds - check engine light appears -1 more second - truck starts.
Truck immediately dies - if I give it a lot of gas the truck will stay running - as soon as i stop giving it gas truck dies - loud squeal when giving it gas from belts

The reason I'm so confused is I can see fuel spraying and it will start so I must have some spark and fuel. I would figure if my fuel or spark was off a little it would still run but just real crappy. Plus, this all happened the 1 time I pulled the headlight switch so somehow that problem is related.

[VileZambonie]

Recheck your fusible links. Give a good tug on them to make sure they aren't fragile. (disconnect battery when you do this)

[tc197]

I've checked the fusible links many times now and I don't see any problems with them. One at the starter, one at the battery, one at the junction box on the firewall, and one at the alternator. As I am doing research on the site I see people saying that the junction box up by the firewall has multiple wires coming out of it and for me this is not the case. I only have 1 wire into the box and 1 wire out of the box with a fusible link on the wire leading in. Is this a problem?

[VileZambonie]

Either you missed something and need to re-recheck or you did not properly connect your grounds. Recheck the back of the pass cylinder head, my the T-stat housing and check your fuses at the fuse block.

[tc197]

So I never pulled any of the grounds off but it could be possible that I broke the ground on the back of the passenger cylinder head when the motor was tilted back for the trans swap. When you say back of the cylinder is it something I should be able to see? I can feel 2 wires going to that general area but I can't actually see them due to the limited space. What is that ground going between? Is it the cylinder head to the firewall? Can I test that ground by just adding a new ground next to it to wherever it needs to go?

I appreciate the help. I've checked every fuse multiple times and none of them are blown.

[VileZambonie]

Check the bulkhead connector and all of your wiring connections. Push the fuse box toward the firewall and make sure it is tight. Run an auxiliary ground from the battery to the engine block then perform the tests again in the chart.

[tc197]

I took the fuse box completely off already and made sure everything was clean and seated properly when I reinstalled it. I also do have continuity from the negative battery terminal to the block but I can run a second wire. Where did you find that chart? I need to find the A-1 chart because when I ignition on my check engine light does not come on. It only comes on once I start cranking the motor for about 3 seconds.