Yotapowa

I ran my truck to almost empty for teh first time since ive owned it, I was putting some injector cleaner and higher grade gas in to try to smooth out the idle. Now, even with a full tank, the low gas light stays on. The gauge reads full, and i tried turning teh truck off then on once the gauge crept up to the full mark. its a 22RE 1986 SR5

thanks

85TurboRunner

Pull out the bulb, no more light.

MaK92-4RnR

these years came with a gas idiot light? what about a 92? mine's never came on since i've owned the truck... heh

85TurboRunner

I have some gauges out of an 87 runner in my 85 and the gas light stays on all the time too, I just ignore it but I will eventually just remove the bulb.

Yotapowa

I just find it strange that it suddenly got stuck on, I would prefer to have it working

camo31_10.50

the sensor in the tank might have gotten stuck?..or broke

85TurboRunner

Try unplugging the battery, maybe it will reset something.

Yotapowa

you know your probably right..my old Yota had the gauge always saying full, but the low fuel light still worked.. hmm

aviator

You mean yours actually works?!... amazing... I've never heard of one that actually worked... wish mine worked...

camo31_10.50

when my low fuel light comes on in my '86..i then know that i have about 30seconds of run time left before it shuts off...LMFAO..it'd be better if it came on when i had like 5minutes left

luckily the last time it came on i was in my driveway LOL

iamsuperbleeder

lol, I wish mine even worked but of caurse, mine's not even suppose to have the light... I did an SR5 gauge swap, but I don't have the sender at the tank... I know there's an extra signal wire from the tank that runs that light, but I'm not sure if it's the same sender or not; that seems kinda stupid to me if they put in a completely separate sender float unit just for the low fuel light... but it is possible that something's stuck at the sendor in the tank. Try taking it down a really bumpy road; maybe it'll jar it loose, lol

aviator

Ok I have a few ideas that may solve your problem and also explain why the idiot lights don't work for many of the rest of us.
Looking at the wiring diagram (see link here http://www.ncttora.com/fsm/1990-1995...i/combmete.pdf ) at the left side of the page you see the connection pt. on the meter for the fuel gauge/light/sending unit etc.
We see that the ground on the sending unit is made by the Brown wire in the BL1 body harness... if your gauge works we can ignore this one the system ground is good. Next we see that the gauge signal from the variable resistor is carried on the Yellow wire with the red stripe (Y-R) to pin 7 on the C14 harness plug (this is I think the white one of the three that connect to the gauge assembly) If the gauge works this is good.

The signal to the low fuel light is carried on the Yellow wire with the blue stripe (Y-L) to pin 3 on the C14 plug. This is the one we are concerned with, it carries the signal from the thermistor in the tank to the light in the gauge assembly. Either the thermistor has failed in the on condition (possible) or the wire is shorting to ground somewhere along it's route (likely imo) or there is a short within the gauge itself (unlikely imo).

Looking at the part#s (from toyodiy.com) there are two diff. senders depending on if you had DLX/SR5 model (truck) and different ones depending on if you had the larger tires or not (4runner)... strange IK but there it is...
part#s (trucks) are 83320-80127/80178 $150 range(SR5) and 83320-80128 (Japan made DLX) or 83320-80179 (Nummi made DLX) both $80 range.
the 4runners were 83320-80207 $150 (10.5*15 wheels) 83320-? $80 for the others.

From the two diff. prices it's clear some sending units have the thermistor others don't (or maybe not lol). In any case the thing to do is to start with the wiring harness and go from there I think the harnesses in this case are all the same.
The diagram above is for a 4runner but the colours should be the same on the truck, in any case the pin locations will be the same.
Hope this helps everyone a bit.
Aviator

davo247d

lol my fuel gauge dosnt work but the idiot light does so im gonna use that for when i need to fill up haha

aviator

Well davo your problem is either a malfunctioning gauge (unlikely they are pretty solid), a bad wire (Yellow - Red on pin 7), or a failed sending unit (most likely). The senders are fairly easy to fix (if the tank is empty) you need to drop the tank and remove the 6/8 bolts securing it to the tank. (4runners may have an access panel in the floor under the rear seats IDK). The bolts may be seized there are a few choices to try to free it up if it is... if you have to resort to heating them up use extreme caution and work in a very well ventilated area or better yet take it to a professional.