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Wedge Low Coolant Light

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JFS

JFS

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The low coolant dash warning light on my TR8 will not go out. A perusal of the wiring diagram has given me no understanding of how the circuit works or where to begin trouble shooting. Can anybody help me out?
 
I'm just guessing from looking at the diagram; appears to me that the probe is looking for coolant to conduct a small amount of current to ground, the module is trying to sense that current and turn on the light when the current is missing. So I would probably start by connecting a jumper around the sensor to ground. If the light goes out, likely the sensor itself is bad (or eroded).

If not, try disconnecting the lamp wire from the sensor. If the light still stays on, there is a short or miswiring somewhere else. After that, it's probably the module.
 
Thanks for the reply, Randall. Light stays on when disconnected from sensor.
 
Thanks, Elliot. I'm not experienced in playing with printed circuit boards, but at $5.35, what can I lose? I'll order the parts and disconnect the light in the meantime. Thanks again.
 
Before you order parts, I would advise doing some troubleshooting to see if the components are bad.
 
If I'm guessing correctly, then disconnecting the sensor should keep the light on.
 
As I recall, disconnecting the ground wire coming from the sensor extinguished the light.
 
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