Oil light not working

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Mopar92

Mopar92

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I have an autometer oil and temp gauge in the car. But It would be nice to get my oil light working. It was working with the slant 6 when I pulled It this winter. Now after installing the 360... it’s not. Because I used the port on the block by the distributor, I installed it on the oil filter adapter plug. Am I not getting a ground or something with it there? How do I test it with my multimeter to find the culprit? Thanks.
 
The sender for oil warning lamp operates on 12 volts ( gray wire ). No oil pressure = switch closed = lamp on. 7 to 9 lbs oil pressure = switch open = lamp off. So is not working lamp always on or lamp always off?
 
It’s always off. So the connection should have 12 volts at the sender? Thank you.
 
Take the sender wire and clip it to a good ground. Light should come on with the key in "run" It is a "series" light, circuit path is sender "ground" when switch made, through sender wire, through bulkhead connector, through cluster connector to one side of lamp.

Through the lamp other side is connected to switched 12V from ignition switch.

And yes.........with key in "run" you should measure battery V at the sender wire to ground
 
Most will just install a 'T' fitting to place 2 senders at top end oil port.
Burned out bulb maybe ?
 
If the sender connector has 12 volts, and I hook it to the ground... won’t that like tig weld or something. Sarcasm. Guess it’s a ground wire and the sender completes the ground? So there won’t be 12 volts? I’m confused. Thanks
 
If you hook the sender wire to ground it should light the oil lamp. If it's a gauge it should quickly send the gauge to full scale. The oil light sender is a switch to ground. Pressure= switch open

Read what I typed above about the circuit path. You go from 12V through the light and to the switch. The light is wired in series.
 
Mopar92 said:
If the sender connector has 12 volts, and I hook it to the ground... won’t that like tig weld or something. Sarcasm. Guess it’s a ground wire and the sender completes the ground? So there won’t be 12 volts? I’m confused. Thanks
Click to expand...
All wires have current on them at some point. There is a positive side and a ground side of a circuit. At you amp gauge there's a red wire and a black wire. There are a bunch of circuits with chassis ground points downstream of this large black wire but make no mistake ... it is hot. Anyway...
The 12 volts you'll measure on this oil sender wire is what travels through the bulbs filament. No welding with that.
 
I’d say it’s not ground where I mounted it to the oil filter adapter. Which is insulated by gaskets.
 
Mopar92 said:
I’d say it’s not ground where I mounted it to the oil filter adapter. Which is insulated by gaskets.
Click to expand...
Use the “T” fitting like mentioned above. Quick and easy and keeps all the wiring in the same place. Not sure how you installed it at the filter adapter. Did you drill/tap it?
 
No. Every adapter I’ve ever owned was drilled and tapped. Seemed logical at the time. I didn’t T because I didn’t have one when I plumbed it.
 
Mopar92 said:
No. Every adapter I’ve ever owned was drilled and tapped. Seemed logical at the time. I didn’t T because I didn’t have one when I plumbed it.
Click to expand...
I see. Many including myself have used the “T” in the factory location. Makes life easy. Wiring is smooth and hidden with the main harness. Picked my “T” up at Home Depot for $2.49. Took about 10 minutes total.
In the other case, if your adapter is insulated by gaskets it will not work. The pressure switch needs to be grounded to complete the circuit for the light.
 
See it.

6224D0AD-1CE1-4C3D-8F60-63FAA0B465A3.jpeg
 
HMMMmmm there are a lot of gaskets there. I never considered that kadapter not being chassis ground. I can't argue the theory. If that's the case, a different 2 wire type sender is a solution. Route the ground wire back and up the firewall to the ground point there. All that versus the 'T' fitting at top end port.
 
There is zero chance that adapter is not grounded. But it's easy to check the light I already told you how.

1....Ground the sender wire. Turn the key to run. Does the light work?

2....Put your meter on low ohms. Stab one probe hard into the block/ pan/ somewhere to get ground. Or clip it to the battery NEG

Stab the other probe into the adapter. See if it shows continuity
 
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