I know this is long winded but maybe I can provide you with a little laugh and maybe save someone some frustration along the way.
So I picked up an 87 Suburban 1/2 ton 4x4 to use as a hunting \ ranch truck. I replaced the power steering pump and the battery and she fired right up. I took it for a little drive and everything major seems to work fine. Runs and shifts smooth and the four wheel drive engages, with a bit of a clunk but it works, high and low range both. All and all I'm pretty happy and I'm thinking it was $750 well spent.
The PO had gutted the interior and in the process simply cut all of the wires for the power windows and locks. I figured this wouldn't be too hard to correct, just match the colors, right! NOT ! ! It seems that these wires had been cut more than once and several different wire colors and types had been spliced in. Again, not a big problem just a little more work. Thanks to some of the wiring diagrams I found on here I knew which wire color should do what so off I went connecting the windows. Low and behold, all 4 windows worked very well once properly wired. Again... everything is moving along quite nicely.
Now to my "lesson learned" part...
In my haste to get the windows tested and working I simply stripped and twisted the connections. No crimp connections or tape or anything. After several up and down cycles I figured I should start the truck to make sure I didn't run the battery down. As I reached in to start the truck I moved the master window control switch on the driver side. As I turned the key I hear snap crackle pop from the driver door. No, there was no milk or cereal anywhere around!! I quickly turned the key off and checked the wires to find a couple of them with burn marks. Ok, i separated the wires and tried to start the truck only to find the entire electrical system was dead. No check engine light, no power to the windows, no headlights, no brake lights... nothing. It was as if someone stole the battery when I wasn't looking. By now its dark out and I'm digging around under the dash with a flashlight trying to check for burnt fuses or anything else that looks burned. Nothing. All of the fuses look good. I dive under the hood and check the battery, 12+ volts. I check the terminal block on the firewall, still have voltage there. I did some quick searching on my phone and come across some info on "fusible links" from what I can tell they are still all intact. It's about 10pm on Sunday and I've got a 2 hour drive to get home and I've got to be up by 5am for work on Monday so I was forced to shut it down and regroup.
For the next couple of weeks I’m stuck working on weekends and such so no progress on the truck. In that time I’ve been pouring over everything I can find in the way of wiring diagrams and posts on several forums regarding electrical problems on suburbans and on GM vehicles from this time period. I’ve pretty much talked myself into the problem being a burned fusible link or something worse like a toasted wiring harness. Finally this past Saturday I had a chance to run down to my brothers house and work on the truck. I’m armed that a couple of Chiltons manuals and a whole stack of wiring diagrams found online I set forth to fix this thing.
The first thing I noticed was that when I put the key in the ignition the buzzer came on. I tried the headlights and they worked too. Strange… I turned the key to run and the check engine light came on. Even more strange… When I left the truck it was as dead as dead can be. I tried to start it and I got one click from the starter and everything went dead again. No headlights, no buzzer, no nothing. What the heck is going on?? So I set forth on a mission to figure this out and fix it for good. After a couple of hours of crawling all over the truck and checking everything I could think of I’d not made any progress. All of the fusible links were still good, none of the fuses were blown and I could find no burnt wires. The only thing I found was that the voltage was dropping the farther I away from the battery I went. Hmm??
My buddy and brother who were there only to rib me and make sure I didn’t shot something finally stopped making wise cracks and suggested cleaning the battery terminals. I dismissed this as I’d cleaned them when I installed the new battery the day before all this mess started. They insisted that we needed to clean them so I gave in. If nothing else it would shut them up for a little while. I unbolted the battery and showed them the nice shiny terminals and they said what about the wire? At that point I thought, “dang it he might be right”. Unbolting the terminal from the positive cable revealed a nice pasty green blob of copper that might have been stranded at one time, 25yrs ago. I stripped the cable back an inch and it was still green, another inch and still green but not as bad. At this point I couldn’t cut any more of I’d have to replace the whole thing and there just aren’t too many places to by a cable of that gauge in a town of 2500 people. We cleaned up the wire as best we could with a drill and wire brush then cleaned the terminals again and made up the connection. We repeated the cleaning on the ground wire and at all of the ground points we could find. Time to test it. Yep, you guessed it. She fired right up and ran like a top. All the lights work as do the windows and even the radio. Go figure, corroded copper had killed the whole thing.
So back to those lessons….
- Don’t leave a bunch of twisted exposed wires laying around. Something bad will happen
- Don’t talk yourself into a worst case scenario.
- Stick with the basics of troubleshooting. One thing at a time until you’ve provide it’s not the problem
- Don’t overlook the basics. These are old trucks and stuff breaks down with age and heat.
- Don’t bet on buying the beer when you’re buddies are around. Dang they can drink!!
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