96 2.3l I4

I'm having some issues with the temp gauge, its always on cold and I'd like to fix it. I tried grounding the 1 wire connector to the sender on the side of the engine and the gauge didn't move. I tried getting the gauge from a 97 from the scrap yard and it also did not move when grounded ( haven't driven around with that one in ).

I read another post here ( didn't want to bump it as its 3 years old now ) that the resistor on the back of the gauge should be 92 ohms. I tested both of mine and they're ~53 ohms. Is that going to cause the gauge to sit at cold all the time? One would think if the gauge rises with more power, then less resistance would give a higher temperature? ( unless thats now how this gauge works ).

the 2 wire temp sensor on the front of the engine is new, I haven't tried shorting that as I think that just feeds the computer, and the sender on the side feeds the gauge?

 

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...

 

OK got out the multimeter and did some testing.

On 20k ohms setting the sender to intake manifold was 8.66, seems high for a cold sender, might have to replace that as well.
sender wire to engine was 1.48 on 2k ohms

The 3 pin plug that the temp gauge goes into, top left, top right, bottom; all on 2k ohms were .010, -0.003, .185 while the sender wire was properly grounded.

So I feel like I must be going nuts, as I looked again and the sender wire is sheilded and I have no idea where that unshielded wire has dissapeared too. Anyways with the 96 temp gauge and a properly grounded sender the gauge doesn't move, with the 97 temp gauge in it spikes all the way hot like it should. yay!.

I guess if I just put in that 97 part cluster of temp & fuel gauge, I should start the truck now to make sure the fuel gauge moves to approximately where it should be?

 

Ford temp gauge is usually 220degF at 1/2 way

Thermostat should be a 195degF(give or take) so after warm up needle should be above 1/3 and below 1/2
You want an operating temp of 195-200degF for best MPG and longest engine life.

Hauling a load or going up a long grade needle should get up to about 1/2, if outside temp is high, above 80degF it can get just above 1/2 under load.

2.3l doesn't generate alot of heat, hard to keep them warm when outside temp gets under 32degF, they make a 205degF thermostat for these, just to keep heater working in winters, lol.