guster900

So just when I thought I had the car fixed, my brother goes out and drives it, calls me an hour later and can't get it out of park. I went and did the shift lock override and got it home, and found out there was a 10 amp fuse that was blown. The one that does the A/T lock and turn signals among other things. I replaced it, all was good. Two days later. He calls me this morning and the car won't start, has power, but won't crank. So I pull the starter relay in the engine fuse box, and switch it out, sure enough it was blown. Car starts up fine, no problems for now.

My question is what would be causing these fuses/relays to blow? All I can think of is a short circuit, some bare wire rubbing, but where do I look? I have no idea how to go about diagnosing this problem or how to get to any appropriate wiring. Appreciate any help.

REDZMAN

Could be hundreds of things, others have had problems like this.

I had a 1997 manual that had a similar problem, and after a few years we found out the problem. The wiring harness from the ECU goes along the back of the pedals, up above them, and then out into the engine bay somewhere near the gas pedal ARM. The arm is the long part the pedal is attached to. In warm weather, and it's always warm here in NM, the arm would hit the ECU harness when shifting (same could happen with an auto when letting off or on the gas), and eventually damaged the wiring causing multiple shorts, and a NON running car. When it cooled off, the wiring would stiffen back up some, and the car would drive easily.

First place I would look is there. Follow all the wires that go to the fuse you blew, and check them for damage/shorts.

tanc

Multimeter is your friend.
Google is your friend.

I'd wait first and see if/when another relay/fuse goes. It could of been a fluke/old relay and fuse. If it happens again, start tracing the wires for shorts.

guster900

Well, I took off the panel under the steering wheel. Spent awhile searching all those wires, just visually inspecting them. They all look perfect, clean no rubbing from anything. All connections tight. I moved to the engine bay, took out the air filter assembly & battery. I unbolted the engine fuse/relay box, popped the bottom off, and all the wires were very clean & secure. So I kept following wires down & around, cleaning connections, making sure kinked wires were still ok and zip tied in place. I didn't want to spend to much time on it, but I did fine two things, and I don't know if either could cause the specific fuse or relay to blow.

One wire leading to the main radiator fan had a small cut with exposed wire. I don't know if or what it could of been contacting, but taped it up. Also, the drivers side lower little fog/marker light on the bumper was out. The connector was broken, bulb in it, but with metal from the connector exposed and could of easily been hitting a metal screw, although the screw only went through plastic. So I removed that until I get a new connector. I doubt either of those things would do it, but what do I know. What do you think? Are either of those even possibilities?

Then I remembered a big stupid mistake I did. At one point a week or so ago when I was mad about having to take apart the radiator fan assembly for a second time, I started working on it with the battery connected. My socket hit the positive terminal while attached to a bolt or touching some other metal, so a nice big shower of sparks came off it. Could that of sent any surge through into the fuses/relays, weakening them, allowing them to easily blow now? I don't know, maybe they are just old at 170,000 miles... oh well, I'll wait to see if another goes.