kyle_22r

yesterday night when i was about to head home, i started my '79 and flipped the lights on, and to my suprise, nothing would light up on my gauges and heater controls! everything still worked(speedometer tach etc) and my idiot lights were fine, but the backlights for everything are not working. i checked the fuse box this morning and noticed a 20A fuse where a 10A one should be in the gauge slot, so i'm pissed off that the guy before me did that. i never smelled anything burning, and i'm really stumped right now about what's going on

anybody know where i should look for problems, i've checked all over the truck and not found anything wrong. my tail, head and brake lights as well as turn signals still work, but the gauge faces won't light up for some reason

kyle_22r

well, after searching all day with little luck, i've noticed that i seem to not be getting any ground. my power wires seem to be fine, and they get power to the light bulbs but there's no ground...

kyle_22r

well i finally figured it out. the rheostat was shot. strangely, i think it was reversing the polarity of some wires, since one of my grounds tested as hot yesterday

i cut the plug off and bridged the wires, i don't really use it anyway and wont bother putting a new one in unless i come across one for free or close to it

cabbage

Hi Kyle_22r.
The same thing happened to me too! Yesterday, after a day of wheeling on our way back to camp on the dunes, my dash lights went out, after leaving early and having Firsttoy follow me home, I couldnt find anything wrong.... the fuses were all fine! right fuse too!
So your problem was the rheostat? Whats that?

we did quite a bit of water crossing though....

Thanks in advance!

MTL_4runner

The rehostat is the little dial you turn to dim the dash lights.
All it is is a little potentiometer (variable resistor) but when it goes, so do the lights.

cabbage

Ahh!!!! Thank you so much!!!!! I'll go test it later! Hope its just that!!

cabbage

Ok... good news: my rehostat is fine........ bad news: no fuses are blown... when I turn the knob for parking lights, I can still hear the relay go on.... Oh and dont know if it happened at the same time the dash and other lights went out or after I restarted the truck yesterday, but my clock was reset! Guess it rebooted....

Anyone know what else should I check? I'm gonna try all the lights tomorrow.... :cry:

kyle_22r

hmm...i remember that when i tested my rheostat it would work if it was cranked all the way on, but move it a little and it would die. no lights came on anyhow. i cut the 3 wires that come out of mine and twisted them together, and all my lights worked again! only problem was that a few of them were dead for some reason, and i'm going to have to eventually replace them

cabbage

I checked the rheostat and it works fine through out the range(checked with a meter set on check).... Dont have time to check all lights, could it be my rear dome light switch?

kyle_22r

hmm..don't know what to say then

i've always had a philosophy with toyotas. mechanically they'll never fail you. but if something electrical breaks, watch out!

cabbage

Ok cant give up, I looked at the wiring diagram and the only thing that I can see that might effect the whole gauge/tail lights going out is the tail light relay... does anyone know where it is? and how will I test it if I find it?

Thanks!

SKREEMR

Sounds like we are having the same problems...My tail lights work, but dash lights do not.

cabbage

My tail lights dont work... but stop lights do... do you mean stop lights? Hmm.... did you do anything to your truck before the lights went out?