Gauge Cluster Weirdness - Coolant Sensor + Drive Light Not Working

[JayBroni]

I have a Gen 3 1996 I4 Camry. The issue I am trying to fix is that the coolant temperature gauge stays at cold and doesn't move, even when the engine is warm. I did a lot of reading and I replaced the coolant temperature sensor and the thermostat. The problem did not go away. So I purchased a gauge cluster on Ebay thinking that would fix the problem for sure. However this did not fix it. In addition, I noticed that on BOTH gauge clusters, the green "D" light doesn't turn on in the center of the cluster. I thought that the light was just burned out before, but that can't be the case. So here's what I know:

1) Thermostat is working fine.
2) Coolant temperature sensor is working fine -- I can watch the resistance across the terminals of the sensor rise as the engine cools.
3) Gauge cluster is working fine -- measured resistances from the electrical manual and they are within spec.
4) Coolant temperature gauge is NOT WORKING. 'D' light is NOT WORKING.

I am beginning to suspect some kind of wiring issue here. Does anyone have a suggestion as to what to do next to fix this issue?

BTW I measured the voltage on the input to the coolant temperature sensor from the connector that connects to the gague cluster. It stays at .2V and doesn't go up or down.

[dc_98_cam]

The wiring diagram for your car shows a connector C10 that plugs into the back of the gauge cluster. This C10 connector is the one that goes to the water temperature sender and also supplies the circuit ground. Maybe you could locate this connector and spray it with electrical contact cleaner a few times. There is a location diagram for C10 on page 32 of the wiring diagram found here;
http://www.**********s.com/camry/camry94wiring.pdf
If there is a problem with the coolant gauge readout, and it is not internal to the combination meter that is inside the gauge cluster, then that problem would have to be somehow related to the C10 connector, or something connected to it.
The diagram for the coolant temperature sender and the combination meter is located on page 236 of the link above.

[95PimpingCamry]

Originally Posted by JayBroni

In addition, I noticed that on BOTH gauge clusters, the green "D" light doesn't turn on in the center of the cluster. I thought that the light was just burned out before, but that can't be the case.

Why can't that be the case? I know that because the car is in drive most of the time, the "D" light is the first to burn out (and it burns out fast, relatively). Mine burnt out at 60k miles.

[JayBroni]

I may have figured out the problem. I replaced the coolant temperature sensor (with the two-wire socket) and I thought this was the same thing as the "coolant sender gauge". Apparantly that's not the case?

Someone on another forum said what I replaced was the ECU sensor, not the sender gauge. Does that sound right? If so, where is the sender gauge? Right next to the coolant sensor?

[mr.pringles]

wait so the 'D' light on the cluster is suppose to be on while your transmission is under 'D'? if so, then i think mine burned hell a long time ago

[dc_98_cam]

The water temperature sender unit, which is associated with the water temperature gauge within the instrument cluster, appears to be labeled as W2 on page 31 of the previous wiring diagram link.
The wiring diagram shows the wire to the sender unit should be yellow with a green stripe.
There are at least one, and maybe two other different water temperature sensors, but they are not related or connected to the instrument gauge
Is this W2 gauge the one that you replaced?
If you haven't replaced this unit, first check the associated wiring connector for good contact .... remove the lead connector clip, spray with cleaner, and replace. If the instrument gauge still does not respond, then you might try installing a new W2 sender unit.