Vehicle: 1993 S-10 Blazer 4X4 4-Door
Problem: Electrical Short(?) in the system controling the Power Door Locks, Power Drivers Seat, Remote Rear Window Latch, and 4X4 Transfer Case.

The breaker in the fuse box under the dash controling all of the above mentioned functions will get EXTREMLY HOT and all listed funtions will cease to work. I thought I had if fixed yesterday by replacing the driver doors power door lock actuator, but late today the problem came back. I've replaced the breaker twice, so that's not it. Funny, though, the new actuator is doing about the same thing the old one was doing. It sometimes locks the door and then it sometimes doesn't. Is there a relay or something that operates just that doors power lock that needs replacing?

A while back in the middle of the year the rear window release quit working, but then started back working later and has operated correctly since then. Of course, except for now.

Any help will be GREATLY appreciated! This is my sons vehicle he has to have in Auburn, AL at college. Right now he's borrowed a vehicle while I'm trying to diagnose this problem.

Dale

 

Check the wires under the drivers seat...

You'll have to trace all the wiring in the affected systems... But start with the wires under the seat, they sometimes get worn through.

 

To elimate components, start by unplugging them one at a time and check the power draw across the breaker. If one of the components in that circuit is bad, unplugging it will cue you in on it. After unplugging each of the components, unplug them all and check for current draw across the breaker. If there still is a draw, you'll have to dig into the wiring and trace each wire.

 

Taking drperry's advise, I looked under the drivers seat after moving the seat all of the way forward. What I found was the main two wire harness pinched between a the carpet/floor and the track that the seat moves on. I took the seat completely out and (luckily) found that the wires were not cut, just the insulation was stripped off. A good amount of electrical tape later and the re-installation of the seat proved that this possibly (probably) was the cause of the problems. At this writing, everything was working correctly.......................except for one thing. The BRAND NEW door lock activator/motor I purchased yesterday for the drivers door _will not_ lock either with the thumb switch or the key fob. It _does_ unlock automatically, but will not lock. This is the same thing that the one I took out was doing, and of course AutoZone will not take it back now that the new one is installed.

Will a bad relay be the cause of this particular problem? If so, why would it work in the "unlock" mode but not in the "lock" mode? And the main question, where in the hell is the durn thing. I've looked all over for the relay and cannot find it. The manual and the Haynes manual does not help either.

Dale

 

Could be a bad relay, or a bad connection on the actuator, or another borked wire...

 

*Moving to 1st Gen Tech*

Yeah, I would be looking for a broken wire in this case as well.

I have emailed a link to this post to myself so that I'll remember to look up the wiring diagram for this system on your truck tonight when I get home from work.

*EDIT*

Ok, here ya go.


*click for full res image*

I suspect that the gray wire is shorted to ground if all other doors work but this one. I would put a test light on the gray wire at the actuator and push the lock button. If you do not get +12V, you have a problem with the wire.