: LT1 Engine Coolant Temp gage - Clarification ?



scurling
07-10-06, 10:57 PM
Ok, long story , short, I replaced the oil tube for the dip-stick this weekend. The rubber top piece was heat deteriorated and came off all the time. To fix this, the entire tube must be replaced.

It's no big deal to replace, but I broke the wiring connector clip on the temp. gage next to the engine block tube inlet, so now I'm looking for a replacement connector. You know how those plastic clips get brittle over time, and when I pulled up on the clip to disconnect it and move it out of the way, it broke off.

Now, help me understand this temp item. The SM calls it "Engine Coolant Temp Gage", but the only electrical item I can find on the schematic is called "Engine Coolant Temp Sensor" located in front next to the thermostat, and "Engine Coolant Temp Switch".

What is this "gage" item?

BCs71
07-11-06, 05:12 PM
Now, help me understand this temp item. The SM calls it "Engine Coolant Temp Gage", but the only electrical item I can find on the schematic is called "Engine Coolant Temp Sensor" located in front next to the thermostat, and "Engine Coolant Temp Switch".

What is this "gage" item?

The sensor located in the front of the water pump (has the electrical connection) is indeed a temp sensor. It is one of two sensors, actually, in an LT1 engine.
The purpose of this sensor is to feed the reading back to the PCM. This is an integral part of engine operation, fuel management, etc. It is what the car uses to turn on cooling fans and all functions via the PCM.
If you hook up a scanner to the car and read realtime data, this sensor will relay the coolant temp. I believe, also, that the temp display function of the climate control center displays info from this sensor.


The OTHER sensor you damaged in the passenger head near the dipstick serves no integral function really. If we had a dashboard temp gauge, this sensor would feed the info to it. The cousin LT1 cars (Impala, Caprice, Roadmaster) have gauges and this sensor runs the gauge.
The only thing I am not SURE of is whether or not the idiot light for coolant temp on the dash panel is fed by the sensor in the WP or in the head..... my guess is that it is a logic function of the PCM, therefore triggered by the WP sensor. But I could be wrong on this point.

ralphb
07-11-06, 07:51 PM
Can't you buy a replacement solderless connector at your typical auto parts store, or maybe even Wal-Mart ?

If you don't have a tool to install these, they are inexpensive to purchase, also.

scurling
07-12-06, 12:21 AM
BCs71

I see you point, and that does tend to track with the SM somewhat. The SM is a little vague. It references the gage item in the 8A-20 section of the SM, but I can't find it anywhere on any wiring diagram, even when looking for the circuit for the temp light on the dash....strange.

I may play with the connection to see if it will engage the dash temp light.

Ralph: The electrical connection isn't broken, just the security fastener clip. The clip that keeps the two mating connectors together. I will probably just fashion a security wire wrap on both sides of the connector. It will keep the two connector ends from vibrating apart.

BCs71
07-12-06, 03:52 PM
BCs71

I see you point, and that does tend to track with the SM somewhat. The SM is a little vague. It references the gage item in the 8A-20 section of the SM, but I can't find it anywhere on any wiring diagram, even when looking for the circuit for the temp light on the dash....strange.

I may play with the connection to see if it will engage the dash temp light.

Ralph: The electrical connection isn't broken, just the security fastener clip. The clip that keeps the two mating connectors together. I will probably just fashion a security wire wrap on both sides of the connector. It will keep the two connector ends from vibrating apart.

I believe Ralph is correct, you can buy new electrical connectors (same as the temp sensor connector) in bins at auto parts stores. I believe they'll call them weatherpak connectors. This would likely be the "right" way to fix it. Not to say that your way wouldn't work either. I broke one of the retainer clips off of my MAP sensor and used electrical tape around the body to 'fatten' it up so it stays in place. Shadetree (or shady, perhaps) works well too, sometimes. :highfive:

Yeah, the Fleetwood may have got that sensor in the head by default even though it may serve no purpose. The same motor was shoved into wagons, Impalas, Caprices, Roadmasters, etc where it was needed..... So maybe the FW got the sensor bacause all LT1s were assembled as a whole before being installed in a car.
It may be possible that sensor serves no function whatsoever on the FW. If it did serve a function, it would be minimal anyway!

CadillacZach77
09-12-10, 07:48 PM
Does anyone know exactly which sensor controls the idiot light on the dash? Mine has been flickering but the temps seem normal. I hope it's the one on the water pump. Every time I look at the passenger side of this motor I get pissed off.

sven914
09-12-10, 08:03 PM
^ The switch controls the light (it just opens or closes based on temperature). The switch will have single wire out of the connector (the sensor has at least two wires).

CadillacZach77
09-12-10, 09:37 PM
The switch is the one in the head right? I was afraid of that.