My truck has an SR5 instrument cluster, for which I sold my left nut to get. It's Temperature Gauge seems faulty because sits on it's peg, dead cold, for the first several minutes, and then springs to horizontal (normal op temperature) in an instant.

I have changed and cleaned the sensor in the intake manifold, to no effect. Finding another reliable SR5 cluster is unlikely.

Based on the beautifully written and illustrated sticky repair description, it seems the problem is most likely in the gauge itself. and I know that I cannot do this type of repair myself. Not going to happen. I have tried to find a local electrical repair shop that fixes antique gauges, but to no avail. Nobody in my area will touch any electronics unless it's digital (or audiophile). (Many shops are refusing to work on any pre-OBD2 vehicle.)

One question I have is whether the temperature guage from a regular Hilux pickup can be swapped into the SR5 cluster.

If the gauge continues to function this way, can I rely on it to read correctly if the engine started overheating, and warn me of a problem, or will it just stay at the normal reading no matter what?

If there is any hazard to relying on this gauge, I would want to add an aftermarket gauge and I am wondering if there is anything special I should know about compatibility between aftermarket guages and the sensor.

As always I'll be grateful for any inputs.

 

Assuming you have a genuine Toyota sending unit, and not one from Autozone or something similar, I'd probably next remove the gauge itself from the cluster and clean all the contact points with 0000 steel wool or a brass brush. I'd also check the connector that plugs into the sender, making sure its clean and has a fairly snug fit.

 

I'd also ensure the wires in the plug are snug and not broken or corroded. Either in the plug it's self, or coming out the back of the plug. And that the connectors that mate the plug to the sensor are clean, and not corroded.
Pat☺

 

And make sure the thread on block where it mounts is cleaned to bare metal and NO insulating sealant is used; that's how the sender gets its ground.

 

Is it possible that you have an "idiot light" switch in place of your ECT Sensor? If you're thinking of cleaning the threads on the block, you'll need to remove the sensor. Don't miss the chance to hook up your ohmmeter and drop the sensor and a thermometer in a pan of water on the stove. Here's the specs: http://web.archive.org/web/201411140...98engineco.pdf

 

Michael, let's start by you telling us what vehicle you're working on.
Model-Year-Engine-Transmission-Trim on signature saves everybody time.
Looks like we're dealing with too many variables here.

On mine (model-year-engine-trans-trim on signature), I used below. It fixed my fake news intermittent running hot issue for $20+:


O.P. is dealing with coolant temp indicating gauge.