Thread: Temperature gauge on dash not working

Originally Posted by aussiebushman

This is probably a stupid question but having checked the electrical manual and fiddled with all the wiring I can find that might cause the problem, I can't find the reason for the dash gauge being completely dead. Where is the temperature sender on a 93 V8? - is it the one immediately next to the thermostat?

And we don't need to tell a man of your experience that unless it is a functioning after market gauge, it is useless for determining when things are getting a little warm, with the needle not moving up from centre until TOO LATE SHE CRIED

You flatter me mentioning my experience but you are correct that I should know better. I took a chance yesterday by driving back to the bush but I checked regularly that the engine was not overheating.

One misunderstanding though - the needle is NOT in the centre - it is not registering at all - just hangs right off the cold end of the gauge.

I just found a thread advising to ground the connecting wire - if the unit is working, the needle should go immediately to "HOT" I'll try that in the morning when I can see what I'm doing. I have ordered a replacement sender from Graeme Cooper's just in case. If that doesn't fix the problem, I can always return it - they are good people.

If you fit a new sender make sure you don't put thread tape or sealers that won't allow it to earth on it. Most senders have a tapered thread or a tapered seat so do not require any sealers.

The dash gauge is normalised so a complete waste of time IMO. I"m sure 50degrees -> 115 degrees reads as dead center "everything is fine". Just fit an aftermarket gauge if you really want to be worried on hot days Ignorance is bliss I'm guessing if on 45degree days towing your temp gauge say "everything is fine here". Much better than knowing your coolant is at 105degrees and you should infact be gettting quite concerned

seeya,
Shane L.

Thanks guys.

I have just spoken with Ward at Graeme Cooper's and now know how it is supposed to connect -There are three wires out of the loom near it.

* the white wire goes to the oil sensor.
* The green-white is the one for the twin terminal temperature sender on the thermostat housing and there should be a black wire on the other terminal that goes to earth However, there is NO black wire so it is now obvious that the idiot "mechanic" who completely stuffed up the radiator change did something stupid because it worked until he got to it.
* The third existing wire is green/blue and that should go to the sender (single terminal) on the manifold

If it works with a new earth, I'll let you know - it may help someone else with similar issues

Originally Posted by aussiebushman

Thanks guys. Have identified the right sender unit where it screws into the thermostat housing but can't get a reading from it - gauge stays dead. There are three wires out of the loom near it. The manual seems to indicate that the white wire goes to the oil sensor and the green/green-white wires are the ones for the temperature sender.

Regardless of which way I connect them, nothing happens at the gauge so it must be either a bad sender, broken wires or the gauge itself. Interesting that the needle flicks back just slightly towards the cold end as the ignition is turned on - then nothing. The same happens when the ignition is turned off.

I'm sure Shane is right - best to fit a separate gauge but that will be a last resort due to the hassles of running the wiring

I will see if I can verify wiring for you tonight. From memory the thermostat switch is for the condenser fans (two spade terminals). I'm thinking the one your interested in has the single spade terminal. I can verify by pulling the wire and see if my temp gauge stops working.

seeya
Shane L.

You are correct Shane - got more input from Coopers but if you can confirm your wiring colours it will be a great help.

I have tested the single- terminal sender fitted into the manifold by earthing it - it does make the needle go immediately to red so this proves it is the temperature sender and that the gauge itself is OK. I have ordered a new sender.

The unit with the 2 terminals IS for the electric fans. Have added a ground wire as Ward advised but am still not sure which colour wire goes to the other terminal of this unit. Ward tells me it should be green/brown but that does not correspond to what is there.

Appreciate your help

Alan

well I'm confused, I was sure there was a single wire sensor there ... but now I can't see the damn thing








I can see the fan sensor, the injection sensor, the fuel rail sensor (injection). Where the hell has the dash gauge gone? Maybe on this motor its hidden behidn the alternator mount?

seeya
Shane L.