ShelbysLex

Hi All, we just picked up a 92 LS400 for our daughter, and I have been nervous about possible problems ever since.. We were told that it needs an alternator, so I brought a good battery and drove the car without any problems. Drove the car the few miles home and my daughter even took a friend for a short drive, all without any problems and no battery indicator lights that I had noticed. We had to pull that battery out and put it back into the truck so she could get to school, but here's what I did next leading to the current problem...

I had a spare battery that I put in the car because I wanted to see if I could determine if the alternator was bad, or just a bad battery previously. This battery was completely dead, so I put the battery charger on it for a while, then got in the car and noticed there were some indicator lights illuminated without the key even in the ignition. I put the key in and turned to acc position and the wipers came on without the switch in the on position. The starter would spin in the start position, but there was no power to anything else on the car including the fuel pump.

I disconnected that battery overnight and tried the one out of my daily driver, but the same thing happened. A few lights lit up on the dash as long as the batt was connected and the wipers come on when I put the key in and turn it.

What'd I do??? I've been worried sick about this wondering if I can fix it myself or if it's gunna cost money that we don't have! I've been searching everywhere, but haven't found this same scenario.

91LS400vgb

Seems like you need to do some electrical detective work; the fact that the wipers came on without the switch in the on position indicates that there is a short somewhere. Most likely you also have one or more blown fuses. One common problem spot that causes weird problems is the electrical wiring by the trunk hinge, but that may not be your issue. I would check the fuses first and then go searching for a short - there are tools specifically for finding shorts or you can make your own using a resettable circuit breaker or flasher relay in place of a fuse.

ShelbysLex

Thanks for the help! While I was just looking through other threads, I realized that because I couldn't get the negative battery cable tightened, I may have fried something while the charger was hooked to it. Maybe shorted the alternator? The fuses under the hood looked fine, but I'll check the box under the dash when I get home as well. I'll try disconnecting the alternator and see if the short goes away.

Feel free to let me know if I'm on the right track, or off base! I got a D- in electronics in Jr High, only because the teacher didn't fail anyone.. I haven't gotten much shmarter in the past 25 years either...

91LS400vgb

Make sure you have a look at the 60 amp alternator fuse in that box. I wouldn't be surprised if it's toast. . The wipers running still leads me to believe there is a short somewhere. I'd recommend getting up to speed on automotive electrical with Tracy Martin's book: .
Good luck.

matchesLS

In my experience, a poor or bad ground can cause all sorts of electrical gremlins. You mentioned you couldn't get the ground tight and that might simply be your problem. The parts store makes a "spacer" for just such a problem. It fits over the battery post making it a tad larger enabling you to be able to tighten the clamp. That and a new battery might fix your problem. Sounds like you need both anyway so give it a try!

PureDrifter

iTrader: (10)

1st make sure the wiper stalk is in the correct position.
2nd check the trunk harness as broken/kinked wires cause all kinds of hell http://www.lexls.com/tutorials/lighting/bulbout.html
3rd check all fuses/fusible links in BOTH fuseboxes
4th make sure terminals are tight and you run a relatively fresh battery.

ShelbysLex

First of all, I'm 40 and have been tinkering with cars since I was 14. The latest build is what you see in my avatar, which started out as a rusty longbed that I've r&r'd every nut and bolt on, welded, straightened and painted... With that said, I humbly, er, stand before you fine folks and admit that, well, I can be a dumbarse at times... Thanks to my electrical savy, and master of the obvious neighbor, I came to realize that the positive batt cable is on the left and that other cable, the one on the right.. Is the negative... After replacing all those dang fuses, the car runs great! Now hopefully my next thread will be on a much more "positive" note! Thanks so much for the feedback I received on this one!

91LS400vgb

Glad to hear you got it resolved.

DonCorleone

iTrader: (6)

Hahaha glad to hear it was a simple fix. Happens to the best of us. Welcome!