Another mystery solved

[djsroknrol]

My L83 had CES light on since I got it, the ECM stored no codes and the coolant temp analog gauge never worked....until the other day.

There was a mysterious green wire running by the radiator. It was obvious that there was a sensor missing a connector but I couldn't find one visually or by the FSM.

Come to find out there are 3 coolant sensors, but the FSM only mentions 2 of them. Looking at the Eckler's flier the other day, I came across a low coolant sensor that goes in the radiator. Looking at my new radiator, there is a plug when the sensor goes....the repair shop didn't replace the sensor in the new radiator ( figures...). grounding the sensor connector got the gauge working and the SES light went out....success...

So you have the analog sensor on the left side controlling the gauge, the coolant sensor in front sending info to the ECM, and the low coolant sensor controlling a non existent low coolant sensor indicator that would not arrive on the scene until 1986.

I wanted to get this out there to anyone having problems solving mysteries; look and question everything. sometimes they change things during production and a look at a newer year model will yield an answer.

oot:

 

[Pete K]

That sensor is still available, if you wish to keep the low coolant level feature working.

 

[djsroknrol]

I've got one coming this week, but with the pending engine work, I think it might be wise to hold off on installing it.

 

[boomdriver]

I've got one coming this week, but with the pending engine work, I think it might be wise to hold off on installing it.

that sensor barely deserves the description of "sensor"...

its just a thin strip of metal inside a rubber plug.

If coolant touches it, that completes the ground. If the coolant does not touch the metal tip, the circuit is open and the "low" light comes on or in the '84, the ck eng lite.