84 LeBaron coolant temperature gauge not reading

[QC DSM ESiT]

Hello all TM guys, I just recently bought a 84 LeBaron T&C turbo convertible with a digital dash cluster. All gauges seem to work alright except for my coolant temperature gauge. I'm not sure if it's the cluster or a bad sensor or both. I thought it was working when I bought it but it seems it hasn't been working since. I'm not sure how to test to see if it's the gauge or the sensor. I'd rather not shell out the money for a cluster I don't need that also might not work so hopefully I can fix this. Any help is greatly appreciated and I'm not afraid by any means to take the cluster out and start testing to make sure. Thanks in advance guys.

[sdac guy]

There is a single sensor for the temp gauge. It is located on the front of the cylinder head (about in the middle of the head) and has a single wire going to it. First try removing the plug from the sensor and checking to see if the connector is corroded. Then plug it back and see if the problem still exists.

If it does, that sensor is fairly cheap, so it is worth trying a new one to see if that fixes it. It would be called an engine temp sensor.

Note the coolant temp sensor is a two wire unit that screws into the side of the thermostat housing near the upper radiator hose where it is fastened to the head. That sensor is what the engine computer uses to see the actual temp of the engine coolant, but it has nothing at all to do with the temp gauge. So if the auto parts store tries to sell you a sensor with a 2 wire connector, it it the wrong sensor.

Barry

[QC DSM ESiT]

There is a single sensor for the temp gauge. It is located on the front of the cylinder head (about in the middle of the head) and has a single wire going to it. First try removing the plug from the sensor and checking to see if the connector is corroded. Then plug it back and see if the problem still exists.

If it does, that sensor is fairly cheap, so it is worth trying a new one to see if that fixes it. It would be called an engine temp sensor.

Note the coolant temp sensor is a two wire unit that screws into the side of the thermostat housing near the upper radiator hose where it is fastened to the head. That sensor is what the engine computer uses to see the actual temp of the engine coolant, but it has nothing at all to do with the temp gauge. So if the auto parts store tries to sell you a sensor with a 2 wire connector, it it the wrong sensor.

Barry

Alright good to know, thanks! I'll give this is a shot hopefully all I need is this sensor and to clean the connector. I really don't want to invest money for a gauge cluster right now. Especially since the convertible top is in need or some repair as well.

[cordes]

Ground the wire that Barry was mentioning (between #1 and #2 on the rad side of head) and it should peg the gauge. If it doesn't, you've got a wiring issue from the sensor to the gauge, or it's the gauge itself. If the gauge is good, then replace the sending unit. It may break off in there, so be prepared to drill it out and retap the 1/8th NPT hole if memory serves.

[85lebaront2]

One other item with the digital dash, there is a board on the back side with a bunch of resistors, they will always look like they have been overheated but that's normal, these are called pull-up board, and provide a voltage to the sender that the resistance will cause to vary, the digital dash converts this to a displacement on the bar graph display. If the temp circuit resistor is open, you will have no reading. If you find it is in the cluster or board, I have a couple of spare clusters and a bunch of the resistor boards.

[QC DSM ESiT]

I figured it out. The wire was just loose. Grabbed some pliers and squeezed the connector a little. Been good since.

[cordes]

I figured it out. The wire was just loose. Grabbed some pliers and squeezed the connector a little. Been good since.

GLad to hear it. IVe had to do the same over the years.