86 fuel and temp gauge on and off again

[TOY2G]

like the title says, I have an 86 T4R 4cyl auto.

The temp and fuel gauges come on and go off randomly and without reason.

I can drive it for an hour and the gauges work fine, then shut it off and its 50 50 if they come back on. some times I will be driving and they will start working, or stop working depending...

When they start or stop, there is noting i can do to make them change.. i can hit the dash, wiggle the wires, move the key around, shut the truck off and on, drive over boulders, even pull the cluster out a little. it only does what it wants,

all the dummy lights and dash lights work 100% of the time, and the fuel warning light still works even if the gauge is off at the time.

I have tried cleaning contacts, testing grounds, adding body grounds, and even taking the cluster apart and cleaning all the contact surfaces and checking for torn circuit board tape. NOTHING.

PLEASE tell me if you have an idea of what to check... when the gauges are working they are correct temp and fuel level, at one point they stayed off for 3 days, but in most cases they come on and off once or twice a day driving about 22 miles.

 

[TOY2G]

Anyone???

 

[SV_Dude]

For someone with nearly 500 posts, you should know that this belongs in the classics section.

**Moved to the proper sub forum**

 

[TOY2G]

For someone with nearly 500 posts, you should know that this belongs in the classics section.

**Moved to the proper sub forum**

Problem is, alot of the Toyota tech guys do not own classics, and would not see the post were it in that section. Being that I need help quickly on this I was going for my best shot to get a reply. All i got was you...lol

perhaps we should have a fix-it section to post in....?????????

 

[helo-mech]

Have you been able to check grounds and what not when they were acting up? Having an interment issue is the worst thing in the world to try and fix. If I am reading the wiring diagram right they share a ground in the left kick panel.

 

[SV_Dude]

I would guess a grounding issue as well. Grounding issues are a real pita and even more so when it's an intermittent issue.

Did I understand you correctly when you said you ran new grounds? If so, where did you splice the grounds into the harness?

 

[TOY2G]

Have you been able to check grounds and what not when they were acting up? Having an interment issue is the worst thing in the world to try and fix. If I am reading the wiring diagram right they share a ground in the left kick panel.

I would guess a grounding issue as well. Grounding issues are a real pita and even more so when it's an intermittent issue.

Did I understand you correctly when you said you ran new grounds? If so, where did you splice the grounds into the harness?

There is a main harness ground in the left kick panel and they also share the same circuit for power. I have waited for them to go off and tried messing with 2 grounds that I have located that may directly affect them....NOTHING. I have tried pulling the ground under the dash when the gauges are working.....still keeps working. I cannot find a single way to make an impact on what these gauges are doing.

i had a new key cut, thinking it could be something in the ign switch...it did not seem to help.

does anyone have the kick panel fuse location diagram. I have the once that shows the fuses cluster, just not the list that tells what each location controls. perhaps there is a circuit that I am missing in all this that has a bad connection.

 

[helo-mech]

does anyone have the kick panel fuse location diagram. I have the once that shows the fuses cluster, just not the list that tells what each location controls. perhaps there is a circuit that I am missing in all this that has a bad connection.

I can shot a picture of the Fuse Box cover if you would like but there may be some difference on the 22RE and 3.0.

 

[helo-mech]

Also found this.

 

[TOY2G]

Also found this.

I LOVE YOU MAN...

that helps, I was checking the wrong fuse. Well let me be more clear, I checked all the fuses, but i was checking to see if the female parts that is inside the fuse block had broken free and was sliding out the back of the block...i was checking the stop lights.

I have hope again, thanks again man.

 

[Yoda85]

Any luck? My 87 had the same problem. Turned out to be a sticky fuel tank float b/c the truck sat for 6 yrs. and the temp gauge issue I traced back to a bad connection at the temp sender. It had been disconnected previously and had loose "jaws" on the female side of the connector. Hope this is your prob! Have you tried grounding out the tank sender to see if the gauge pegs?

 

[KidVermicious]

Helo, that kicks ass. We need that in the Sticky!

 

[TOY2G]

Well I checked the correct fuse. I pulled the fuse, checked the block, put the fuse back in, and started the truck. All was well, so i kept my fingers crossed. Today on the way to work, they both shut off, as I pulled into work they both came back on. AAAHHHHHHHH

perhaps something in the ignition switch.... with the old worn out key, it may be loosing power intermittently..

No clue, but I wont give up.

 

[derek13]

Well I checked the correct fuse. I pulled the fuse, checked the block, put the fuse back in, and started the truck. All was well, so i kept my fingers crossed. Today on the way to work, they both shut off, as I pulled into work they both came back on. AAAHHHHHHHH

perhaps something in the ignition switch.... with the old worn out key, it may be loosing power intermittently..

No clue, but I wont give up.

Every figure out the issue? I am having the same issue with my 1998 except it is the heat gauge and some of the aux lights. (ie seatbelt light, 4wheel drive light, when I have 4wheel drive engaged, and cruise control) They will just come and go as I drive.

 

[fourwd1]

Maybe a bad/loose ground.

 

[RAD4Runner]

yes, most likely a loose/bad connection somewhere.

... it is the heat gauge and some of the aux lights. (ie seatbelt light, 4wheel drive light, when I have 4wheel drive engaged, and cruise control) They will just come and go as I drive.

On first-gens the Engine fuse supplies the dash error/indicator circuits.

I suggest you look at your schematic, find out what power circuit supplies those and trace AND inspect wires.

 

[TOY2G]

Every figure out the issue? I am having the same issue with my 1998 except it is the heat gauge and some of the aux lights. (ie seatbelt light, 4wheel drive light, when I have 4wheel drive engaged, and cruise control) They will just come and go as I drive.

Yes and No.

I converted to SR5 gauges and changed the fuel level sending unit ($$$). I changed the oil pressure switch as part of the gauge conversion, swapped both temp sensors (one for temp and one for cold start). Not sure what the cure was, but the problem was fixed.