ok i got a 90 gxl and my oil pressure guage dont work. i first got the car it didnt work at all. i replaced the clutch and noticed a wire was hanging. it plugged in to the oil pressure sender. then i started the car. the guage still read zero. turned it off and the guage started to go up. im like wtf. does anybody know what that could be.

 

There are actually two wires in that general vicinity that relate to the OP gauge.
One connects to the sending unit and provides a variable ground for the gauge.
The second goes to a condenser that dampens the signal to smooth out the gauge's needle movement.

You can live without the second- many folks are unaware that it even exists- but the first is critical.

 

i have the one plugged in to the sender though. thats y im confused that its not working cause it drops to zero.

 

Try connecting that wire direct to ground.
The gauge should read max pressure...if not, either the wiring or the gauge itself is the problem.
If it does, you just need a new sending unit (most likely cause).

 

alright thanks ill try that. i have to figure out y my car is not starting now. one day is fine and the next the battery is dead.

 

Test the alternator. Does it look really old ...like maybe 20 years old?

 

it doesnt look real old. i had it tested and its pushing 13.3 volts and 68 amps. i know its not 80 but that should still charge it up enough i think. thats what the guy at the parts store told me. it was just recharged 2 days ago. its also a brand new red top battery.

 

Presumably, when you installed the new battery you also cleaned the terminals.

Shouldn't the alt be putting out over 14v?

 

dont mean to thread jack but i have a similar question. on my 86 gxl , my oil press gauge doesn't work also, but the guy i bought it from had an aftermarket gauge installed and it works fine...so does that mean that my gauge cluster is the problem and not the wiring or sender?

 

Depends on how he installed the aftermarket gauge.
Typically it would have wiring and sending unit completely independent of the factory setup, so it doesn't show you anything about the stock parts.

 

i cleaned the terminals. im gonna try new wires to. ill find out about the altenator though