So yeah, I bought this 1988 rx7 about a week ago, when I bought it I saw that the temp gage and the oil pressure gage dont work.

The temp gage just doesnt move, and the oil pressure gage pegs out at the top.

I knw its a wiring problem, because I can see where they hook up, the oil pressure is right underneath the oil filter, and the temp is slightly to the right of that (both of these are on the driver side of the motor)

What I dont know is where the wires would be coming from... and what color they are supposed to be... any help is much appreciated

 

If there are no wires hooked to the sending units, look around. They can't be missed as there is only about 5 inches of wire attached to the plugs. The temp sender plug is bullet shaped, and the oil sending unit is designed to slide onto the unit.

Vince

 

yeah, i was looking in the haynes manual that i got with the car, and i think i might know which wire goes to the temp sensor, but the wire that goes to the oil pressure sensor might be stripped, because there is a wire that is right next to it, but it doesnt have a tip on it... so ive tryed hoooking it up and the sensor still just pegs out at the top... so ill keep looking

thanks

 

Well, welcome to the club!

I was born in San Antonio.. Don't know anything about the town.

I digress..
I just bought a 7 with the opposite problem as yours.

My temp gauge needles up, and my pressure gauge doesn't move.

How do I get behind the console to look at the connections?
I haven't gotten the book yet, because they don't carry them anywhere around here.. had to order it.

Help is appreciated,
Roarke

 

well, ive never taken apart the dash before, but the book says theres three screws above the instrument cluster and theres 2 on either side of the steering wheel on the bottom(under where you turn the lights on, and where the windshield wiper controls are) and the black panel should just come right off, and i would guess you can get to it from there.

Also, check right next to the oiil filter, thats where the temp gage wire is, make sure its plugged in, it should be a yellow wire, and if the temp gage is all the way up it usually means that the wire is grounded out, so make sure its connected and not touching anything metal

Would anyone happen to know why the needle for the oil pressure gage might be all the way up?? I think it might just be the wire is grounded out, but im not sure

 

Make sure your connections to the senders are good/clean. This may not fix the problem, but make sure the oil pressure sender's condenser (looks like a small black box with a ring terminal) is bolted to one of the slave cylinder bolts. You should also try touching the sender wires to ground and off to see if the gauges react. Could very easily be the sender's fault.

The Haynes manual is good to have anyways, but the FSM is essential. Check out my sig. below for it.

 

is the plug to the oil pressure gage a one wire plug??

 

It's a funny plug (yes it is one-wire and the gauge adjusts it's reading relative to the resistance of the sender to ground).

The plug slides into the disc at the back of the sensor (looks like a tiny short nail head) from the side.

 

Yea, I have been needing to replace the Oil Pressure Unit on my car. I dont get any pressure at idle but at 3k rpm, I get right above 30. Strange little problem, gonna take some sand paper to it to see what I can do. Might have to replace that sensor, it's only 40 at autozone.

 

yeah, i saw the connection on someone else's car, but i think the clip is missing on mine, i think he stripped the wire... lol