So, I just bought a 94 pickup but I don't have the speedometer or the temperature gauge. My fuel gauge and all other dash lights work (warning lights, O/D light, etc.).

I was going to start by pulling the gauge cluster and visually inspect.

Any recommendations? I have the Mitchel subscription for it, so I have wiring diagrams and such.

Thanks.

 

Update: pulled the gauge cluster - everything looked fine. Reseated the three electrical connectors. Checked the gauge fuse - fine as well. When I was driving today the speedometer would randomly start to work.

This leads me to think that the speedo and temp gauge issue or unrelated to each other.

Though it would be nice to have the speedo, my real concern is the temp gauge. The heater blows hot so I don't believe the thermostat to be stuck closed. I did read in another thread that there is a 1 wire sensor/ connector that lives on the intake that sends the temp to the gauge - they said to ground it and see if the temp gauge spikes (this would X the gauge and wiring to the gauge out). can anyone verify this? I imagine it would have to be a problem here because if the coolant temp being sent to the ecm was off then I would be running rich? Just speculating at this point.

It's going to get toasty here in MKE soon and it would be nice to not have to check the coolant level before every other drive.

 

This is a sign of a failing VSS1 sensor. Assuming you have the electronic (rather than cable) speedo, the sender is in the back of the transfer case.

The procedure for checking the temperature gauge can be found in the manual here: http://web.archive.org/web/201102052.../6combinat.pdf

The ECT (Engine Coolant Temperature) sensor for the ECM is a different one than the one used for the gauge. They are not related. (The sensors ARE next to each other.)

 

This is great. Thanks! It says a 3.4 watt test bulb - would a normal test light work?

The wording seems confusing to me. If the temp gauge reads hot upon testing - wouldn't I replace the sender gauge?

 

I went through this and was assured that the VSS seldom goes bad. Tells how to test in FSM or on You tube. On my 93 it turned out to be leaking ???? electrical thinggys on the speedometer. Got it fixed at speedometer repair place for $150 and 1 year guarantee. HTH Of course this only applies if you don't have a cable drive speedo.

 

So for yours it was the gauge portion it self? Interesting - when I pulled mine it looked fine. I will have to pull the vss to test it looks like.

Update on the temperature gauge... jumped the temp sender connector to ground and the gauge shot up: this was enough for me to order up a new sender. So now that the sender gauge is installed I DO have temperature gauge readings but it only gets up to about 2/5 ( and it takes a long time to get there - maybe 10ish minutes on an 80 degree day) on the gauge. Since I don't know the history of the maintenance, I am going to drop a new tstat in it this week

 

The gauge is an idiot gauge, 30 years old and not to be trusted in my opinion. I like to check the engine with a temp gun to at least have a vague idea of what the gauge is actually saying. The sender is a thermister and can be tested with an ohm meter. I also do not just replace a thermostat, but test it first. If I replace a stat and throw the old one out and still have a problem I do not know if the old stat was the problem or not?? If it tests good I can see no reason to spend money on a new one??

I have read countless times of people having issues with aftermarket thermostats. Seems some of them are formed in a manner that is not compatible with Toys and will work fine in other vehicles or even when testing. I have read it so often that I would not consider anything but an OE Toy stat for my vehicle.

 

What temperature(s) are you looking for, say, at operating temperature with the gun?

How do you test the sender since it is only 1 pin? My understanding was the the sensor grounds on the intake but varies resistance depending on coolant temp (total guess).

Ill throw the old tstat in a pot and see if it opens up at 160-180 degrees (OEM is 180 but I have a sneaking suspicion my friend the previous owner threw in whatever autozone had that day, ha).

If there is an aftermarket tstat in there now, would you replace it regardless with an OEM?

Thanks!

 

Notice you have a 4 cyl, I have a V6 so my expertise is with the V6, so I am not of much help.

After what I have read if I was unsure if the stat was Toyota or not and I was seeming to run hot I would replace the T stat weather it worked or not. Only my opinion, not to be misconstrued as expert advice.
It has been 3 years since I had my Tstat our and cannot remember if it was marked Toyota or not? Also not sure if I was aware of the Tstat issues at the time??

Also note on the V6 the thermostat can be put in upside down.