Richieb9

Gauge had been working fine on my 93 but I broke the top off of the sending unit when removing my valve cover (located towards the tear of valve cover on this year) so I put a new sending unit in. Started the engine and it slowly goes all the way to max temp within 1min. Like I am not overheating. I already checked the fuse of course and checked the new sending unit with my ohm meter. And checks out fine. I was wondering if there is a way to just check the gauge itself. Or if anyone has ever dealt with these much

Coach

sounds like you got a sending unit for an idiot light instead of gauge.

Radi

I think Coach nailed it. The parts places love to pull this sort of switcharoo.
Unplug the wire, gauge should go full left. Short the sender wire to ground, gauge should go full right.
If there is no in between, it's the sending unit.

Richieb9

You really think so? I even went back to oreilys and had then check to make sure I got the right part number. When I disconnect the plug it goes to zero when its plugged in it goes to max gradually

NewJerseyXJ609

Use a 470ohm resistor and touch the terminals on the plug. The guage should read roughly 235. (And your aux fan should kick on)

Richieb9

470 ohm resistor. Where can I get that? Man that would be a good way to test my aux fan also.

Radi

Radio shack should have them.

Richieb9

Ok I put that ohm resistor on between the plug and sending unit. With the engine at running temp (215* on my laser thermometer) and the gauge is right around 130*. Any ideas?

NewJerseyXJ609

Hmm.. Your sure you got the correct resistors? Here is a crappy small pic of the ones I used lol.

Now I did this test on my 00 to make sure that the fan came on. But it should work the same way for yours..

Richieb9

I got the exact same ones from radio shack yep!

NewJerseyXJ609

Well here are the directions I followed which were given to me by ckken.

Now, on your 93 you will have 2 temp sensors. One strictly for the guage and one for the ecm/fan. I believe the one on the tstat housing is for the guage in your case.

The pic us a screen shot so you might have to zoom in to read it...

And I know this test is technivally to test the fan. But it should also work to test the guage as well bc it will make the guage read 235

Pelican

The 2000 is different from the '93 in that the '00 has only the one sensor (CTS) in mounted in the thermostat housing. The '93 has a separate sender for the gauge located at the rear of the head that the OP broke. That sender has no effect on the aux fan.

An air bubble around the sensor might cause the problem but just changing the sender on the '93 normally will not result in a loss of coolant. Easy enough to check.

I had problems with a BWD sender from O'Reillys several years ago but it was just reading a bit high. I finally fixed that with an OEM sender.

NewJerseyXJ609

Ok yeah I knew the older ones had two I just didn't know which one worked which

Richieb9

Ok well I'll try "burping" the sending unit by backing it out a little. Might as well give that a shot. Cuz I feel like I've done everything else

Radi

It's supposed to go in place of the sending unit, not in between. Bend the leads on the resistor and plug it in the harness plug in place of the sender.