Originally Posted by RonD
Yes, the 2 wire ECT sensor is only connected to the computer.
Grounding the 1 wire on the temp Sender should cause the gauge to go above HOT, When you disconnect wire or unground it should cause gauge to go below COLD.
What does the end of that wire look like?
Is it clean and dry, could just be a corroded connector.
It should be a Red/white stripe wire, it runs directly to the dash, Connector 215 pin 3
Yes, it shows a 93ohm resistor on my diagram.
Does the gauge move at all as engine warms up?
As the sender heats up it's resistance goes down, and gauge goes up, so 53ohm resistor should make needle higher than a 93ohm.
If you still have the dash apart test the red/white stripe wire.
Ground the sender end then test OHMs between dash ground and that wire at the dash connector, should be 0 ohms if wire is good
OK from the top:
Grounding it didn't move it, although this second time I grounded it while it was still plugged in.
End of the wire didn't look too bad, I didn't get a good look as I was under the truck. I figure the end shouldn't matter for grounding it as I had a clip on the outside of that 1 wire ( its a bare wire ). That is unless that bare wire is shielding around a center wire, in which case I'm an idiot..
Gauge stays on cold and never moves, we hauled 5 loads of manure in the box and on that day it never moved at all, I've also hauled wood in 30-35 celcius and it stayed cold. ( the truck heat blows hot so I know that does work ).
Ok that's what I thought, lower resistance should mean a higher moving gauge.
I'll see if I can find the red striped wire to test that, could very well be a grounding problem...