BluesImage

I just did the repair to clean the stops on the speedo & Tach and got everything back together and now the Temp gauge is pegged all the way up past Hot. Any ideas?

power54

Same thing happened to me after i did my caps on tachometer.
I did a coolant flush and still the temp is high.
I am thinking of changing the coolant temp sensor, and the thermostat, and see what happens.
I will change the water pump and timing belt.
If that doesn't do it, I will leave it alone.

Yamae

Which year model?
Judging from the speedo & tach repair, yours must be an earlier model that has an independent thermal sensor for the gauge. It has a Thermistor inside and it reduces the resistance as temperature rises up. Higher the temperature, smaller the resistance.

All the way up past hot simply means something similar to too small resistance of the sensor. I bet the signal line from the sensor is short-circuited to the ground or very low impedance line at somewhere at the cluster area.

In order to confirm this, check the resistance or just disconnect the connector at the thermal sensor opening the hood. If the resistance is nearly 0 Ohm, definitely the line is grounded, or the sensor itself is bad. When the connector is disconnected, the gauge should show below C if there is no short circuit at the line.

If the line is grounded, you need to check the wire line to the cluster is cranched or the related trace of the cluster board has some conductive foreign object such as a solder particle which cause the short circuit.

BluesImage

It is 1995. I think what happened was I had the cluster on my table and it rotated and fell 4 in on the other end of the cluster and hit the table. I took it back apart and I messed with the needle on the gauge and now it reads just below the middle for cold when I start it and just before hot when it reaches temp.

TaninAuto

Common issue. The gauges are extremely fragile. Any drop or even touching them wrong has the chance to break them. Especially if you took everything apart and put it back together again. We see these daily with gauge issues.

My guess is the temp gauge assembly will need to be replaced.

BluesImage

Jason,

I think you are right. Now my speedo & fuel gauge are not reading correct either. So I shipped my cluster this morning with overnight shipping to you guys at Tanin so you will get it tomorrow from me from Woodstock, GA. I know you guys will do a great job with what I've heard about you here on Club Lexus.
Thanks, Mark

TaninAuto

Alright then! We will get it fixed tomorrow for you.

BluesImage

Thanks, I can't wait to get it back.

BluesImage

I got my Gauge Cluster back from Tanin Auto and everything works great! Thanks Jason for the fast turn around I really appreciate it.