first_truck
Newbie
I bought a 1990 GMC Sierra 1500 that almost immediately started having issues it didn't have on my test drive. First I notced some transmission fluid leaking. It was coming from somewhere on the driver's side above the pan and dripping onto the drive shaft and getting flung everywhere. I still have not pinpointed the leak, which only seems to happen when the truck revs up to where it should shift into second gear. It does not seem to be coming from the overflow vent tube. I still have reverse (although it seems hesitant) and first gears. The fluid got burnt very quickly the first time it wouldn't shift into second because I got on it pretty hard thinking that would make it go, but all it did was leak more fluid. I have not dropped the pan or tried to flush the trans yet. Is there possibly an electrical component in there that went bad? The other problem is intermittent. I first noticed it the same day I noticed the trans fluid leak (2 days after buying the truck). While parked and while driving slowly around the parking lot trying to figure out the trans leak the engine would almost die and the gauges on the dash would all drop for a split second every 20 seconds or so. The engine did die once when the drop coincided with me slamming the driver's door which takes some effort to shut because it sags. I have moved the truck a few hundred feet several times in order to mow grass and it had not done the engine faulter/gauge drop again until recently. This time, even with the key out I noticed a ticking coming from the fuse box. A 30 amp circuit breaker (the lower of the 2 "POWER" breakers labeled "BAT") was clicking with the same frequency interval as the gauge drop and was hot enough to burn me. I tried a new circuit breaker, which sparked when I installed it and got hot as soon as I started the truck (or possibly before that). The next time I moved the truck it ran okay. The issue seems to only happen when the engine warms up, and even then only some of the time. Most of the wire loom under the hood has disintegrated and there have been several 'upgrades' in electronics (autostart, backup camera, touchscreen display that syncs with your phone in place of the stock radio - the wiring down by the fuse box seems creative...). The backup camera stopped working when the other issues started, then randonly worked once the other day (and then didn't work after shifting again). The spray for the wiper fluid doesn't work, and the wipers didn't work on my test drive until after I hit a few bumps. The guy I bought it from said he had just replaced the battery and alternator, which now makes me think he was having issues. The negative battery connection was loose and a little corroded, but I cleaned that up, tightened it, and cleaned up a couple ground connections from the battery to the side wall and engine which seemed okay to begin with. I thought that fixed the gauge drop/engine faulter issue, but apparently not. I have been pulling that circuit breaker out when I park the truck so it can't get hot or cause other problems. I accidentally started the truck without putting it back in once. I assumed it had something to do with the battery and that the truck wouldn't start without it, but apparently I was wrong. Probably a short somewhere I need to track down? Possibly in the trans? I've worked on cars a bit, but wasn't prepared for trans and electrical problems immediately after a smooth test drive. Any help and suggestions would be appreciated. Thank you for taking the time if you made it this far.
