Oil light not working

Stevehose

Stevehose

Well-Known Member
Site Donor $$
Messages
13,584
Reaction score
6,501
Location
Sarasota, FL
More electrical issues on my friend's coupe - the oil light does not come on when the other idiot lights do - either before or after starting.

There is voltage to the sender wire and I took the bulb out and tested it and it works.

Would a faulty sender unit cause this or something else?
 
Steve,

my opinion is YES. the idiot light is fed with power and grounds out to the pressure switch. check that the wire is hot with a voltage tester ... the light has to ground out somewhere for it to come on. you might try unplugging the wire and try grounding out the wire ... and see if the light comes on. that should tell you that the switch is faulty.
 
If the switch if not faulty, check for continuity to ground on the light socket. Assuming you can reach up in there (which I haven't yet done), you should get the same resistance reading for each of the idiot light ground connections to the common ground under the dash.
 
It could be the sending unit, but the multi-wire, white nylon sockets behind the firewall / ahead of the gauges are the weakest link in the chain. You could bypass the socket by running a dedicated wire from the sending unit to the bulb and seeing if that fixes the problem.

No easy way to fix those connectors - they are pretty inaccessible.

As rsporsche wrote, you can easily test the sending unit by unplugging the wire that attaches to it and touching it to ground while a helper checks whether the light comes on. If the light does not glow, the sender is probably OK and there is an open connection between the wire in your hand and the indicator bulb. Again, I'd suspect the multi-wire connector.
 
Last edited:
Thanks guys, this is tonight's Happy Hour project.

The other bulbs of the gauge cluster work ok, hoping it's the sender but am expecting the PITA.
 
Happy hour got too happy so I tackled this issue this morning, it's the sender unit, I put an old one on to test and it now works. Glad I didn't have to mess with the bulb wiring behind the dash. Thanks for the input.
 
well that sounds like a typical NOLA story ... good happy hours. glad that was as easy as we thought it probably was.
 
You must log in or register to reply here.
Back
Top