How To Test Gagues/Sending Units

[1989MustangLX]

I've got my wiring hooked up for the temp and oil pressure gauges, thanks to the help I got in the last thread I made. I found the correct wires in the dash, and the engine bay, and I tested them for continuity. I started the car and the oil pressure gauge didnt move. I assume I either dont have it hooked up correctly, or something is wrong with the sending unit or gauge. The temp gauge didnt move at all, but I only had the engine running for a few minutes. Any ideas?

 

[JB66]

The sending units GROUND the gauges. Touch the wire at the sending unit to ground to see if the gauge goes up.

 

[1989MustangLX]

Will the negative post of the battery work? This is a 351W out of a 1979 Thunderbird, I wasnt sure if the sending units worked the same. I'll check it out.

 

[1989MustangLX]

Ok, I ran outside and grounded the two wires, both gauges work. The oil pressure gauge stuck halfway up when I removed the ground wire, but went back down when I started the car. The oil pressure gauge stayed down when the car was running. Maybe the sending units are fried?

 

[JB66]

Get the proper sending units for the mustang. The gauges in the T-Bird operate differently.

 

[1989MustangLX]

Ok, I figured that's what it was. I called the parts store, and they list two different oil and temperature sensors for the T-Bird, one each for gauges, and one each for idiot lights. Do you think the 5.0 Mustang sending units will thread into where the T-Bird sending units are? They have different part numbers.

 

[1989MustangLX]

Posting incase JB66 doesn't check the third page. Thanks for the help so far.

 

[JB66]

Should be the same. If not, you can always get adapters. But since the blocks are the same, they should work fine.

 

[1989MustangLX]

Alright, I'll buy the ones for the 5.0. Thank you very much for the help, I've learned a few things in this topic.