Dashboard warning light malfunction

[mikey]

On the way home on Saturday I nearly missed a turn, and while braking, I accidentally shoved the transmission into first gear for a second. I think that the car stalled briefly, but was back to running as soon as I released the clutch. It happened so quickly that I'm not sure of the exact sequence of events. There was that grinding sound while going into first, since my speed might have been thirty or more MPH.

Since then the warning lights for the parking brake and battery charging system have been on constantly. The battery is indeed charging, since I drove 100 miles home with the lights on, and have driven 50 more miles since.

I've disconnected the battery for a while, hoping that things might "reset", but no luck. Everything seems normal except for those two lights. Any suggestions?

[Petros]

perhaps a ground somewhere got "bumped" and is not making full contact. It is odd since a mis-shift should not affect anything electrical, unless it was a sudden slow down, and something shifted or moved. Is your battery tied down? Or is it loose so it could side forward with a sudden slow down? That would be my guess. Could be coincidence, but it seems unlikely by what you describe.

[takza]

Might have over-revved the alternator?

[mikey]

I checked the battery, and it's securely held down. It didn't move. As for the alternator, I wouldn't know. I'll mess with various grounds and connectors this weekend.

I think that the fact that the brake light is on shows that the alternator light might just be a symptom of some other electrical problem, but not the alternator.

[Petros]

you did check your brake fluid level didn't you? sometimes the light bleed-over makes it look like more than one light is on at the same time. There is a float in the master cylinder that turns on the brake light when the fluid is low.

[splatterdog]

Are you absolutely sure it is fully charging? If you have one diode out it will still charge, just weakly. Both warning lights on is a classic symptom of charging trouble for these cars. Not sure if your manuever would have anything to do with it. About the only correlation I can think of, is if the engine rocked violently a wire may have broken. Fusible link at battery + comes to mind too but that would totally eliminate charging.

I would verify charging first.

[dlb]

interestingly enough, i had a similar experience with my fiancee's toyota pickup recently. the thing ran fine till one day of windy weather that pulled my 10' x 20' car tent up and dumped it upside down on the other side of her truck. there was no visible damage to the truck but the tent was lying against it. we righted the tent and went back inside but the next day when she went to start the truck it was dead. we jumped it, let it run for 30 minutes, and it started fine but some of the dash cluster warning lights were on and the next morning it was dead again. this happened another time before i decided something must be drawing on the battery, after that i pulled every fuse (from all 3 boxes) and measured the current with a meter to narrow down what it was. nothing affected the current, there was a constant draw, and that was the limit of my diagnosing skills. took it in to a friend and it turned out the be the alternator. i guess that even though there was no visible damage to the truck, the tent had hit it in such a way that something in the alternator that was waiting to die finally did. my friend told me that when alternators are REALLY dead, the diodes will draw on the battery and that's what kept killing the battery. your situation is obviously not identical but there are some similarities so you might consider looking at the alternator.

[garyfish]

relevant threads:

viewtopic.php?f=4&t=5472

viewtopic.php?f=4&t=4290

viewtopic.php?f=4&t=4062

viewtopic.php?f=4&t=697

viewtopic.php?f=4&t=536

[mikey]

Yeah, I imagine that the engine did rock pretty violently for an instant, so it could be a loose or broken connection. Also: the brake fluid level is fine. Thanks to qaryfish for the links. It looks to me like I'll be getting a new alternator this weekend. I've noticed several other little quirks over the last year, like the temperature gauge reading a bit higher when the heater blower is on. Since this latest incident, that temp gauge reads lower than normal much of the time. The two glowing lights also dim when the directionals are on. I guess I should consider myself lucky that the battery is not going dead.

Does anybody know where the voltage regulator is located? How could I tell if it's actually built into the alternator?

Thanks much for all the advice!

[tercel4wdrules]

The voltage regulator is located to the right of the battery, a small rectangular box. I haven't compared the connectors in the back to tell the difference. I know the external regulator alternators have the fan blade outside and the internally regulated ones just have the pulley.

[4wdchico]

All the '85 and up t4wd's that I have seen have the internal regulator. My '84 t4wd parts car has the reg. on the fender.

[mikey]

Problem solved: new alternator. The regulator is built in, so there was no question as to which to try first. A super easy repair, but my car has got to stop eating $100 bills!

I never would have guessed an alternator problem at all because of that brake light. This forum is the best!

[garyfish]

If you've still got the old alternator, fixing it for use as a spare could be as simple as changing the brushes. It's easy to check the condition of the brushes -- see the FSM and/or this post:
viewtopic.php?p=39916#p39916

Replacement brushes cost only a couple dollars at your local auto-parts store, and require only modest skill in de-soldering to remove the old set and soldering in the new ones.

[dlb]

that's excellent info, thanks gary!

glad it was a simple solution, mikey. and i agree, this is a great forum!

[Highlander]

You can get the brushes for the '85 qand on from any NAPA store- Gary's right, they cost about $5, you just need a large enough soldering iron to replace them. If you do, don't forget to lightly clean up the commutator rings on the armature (where the brushes ride), scotchbrite works great for that , and you don't even have to disassemble the housing to do it, just stick your scotchbrite and a finger in through the brush access and spin the armature. works like a charm.