Oil Sending Unit Wiring

[Tims 66 Cuda]

I,m installing the instrument cluster in dash. I want to use the dash gauges. I,m also installing Auto Meter oil and temp gauges. My question is can I tie into the Auto Meter sending unit for the original oil gauge or put in a separate sender for the dash gauge, or forget the dash gauge all together. Help appreciated as electrical is not my strong suit.

Thanks, Tim

 

[RedFish]

I dont think so. Most aftermarket gauges operate on 12 volts. You OEM gauges and senders operate on 5 volts. You might put a fitting in the block for both senders.

 

[67Dart273]

^^And the current through the sender is limited "at some point" and I don't know what that figure is. You will likely end up with TWO readings that are both incorrect LOL^^

 

[Tims 66 Cuda]

Thanks for the replies, Did,nt know if it would work even though the original sending unit wire still would have to go through voltage relay for the gauges.

Tim

 

[67Dart273]

"How these work" is a temp sender is what is called a "thermister" which is a resistor that changes value with a change in temperature. Most/ all resistors do this, it's just that thermisters do so with precision predictable results, which is why they are useful.

BUT CURRENT flowing in ANY circuit makes heat, and resistors make heat. So at some point with increased current flow--due to one more gauge circuit, the thing HAS to become inaccurate

The gauge is usually simply measuring current.......the thermister resistance goes down, and the gauge moves up to higher reading due to increased current.

 

[RedFish]

Thanks for the replies, Did,nt know if it would work even though the original sending unit wire still would have to go through voltage relay for the gauges.
Tim

There is a way to get 12 volts into the OEM gray wire so you wouldn't need to route another wire to the aftermarket sender. That would happen at the bulkhead connector and behind the inst' panel. Downside falls on the next owner of this car. I think the next owner would more appreciate strange, pink wires with blue tracers to stuff that isn't OEM. If you won't use that OEM gray wire for OEM oil sender, just tape it away.

 

[cudamark]

I'm assuming that you're working with a '66 Barracuda instrument cluster, and you're just asking about the oil pressure sender? If so, it would probably depend on the specs of the stock sender vs. the aftermarket one. The sender is really just a pressure variable resistor to ground. I don't think you'd be able to run both gauges off the same sender however, unless you could figure out how to isolate them from each other so they don't allow feedback that would act as a ground and give you an incorrect reading. I think I'd just add a "T" and the extra correct sender and wiring for the aftermarket gauges. Same goes with the temp sender. Might be a plumbing job getting everything to fit though. If you're working with a car with an idiot light, you'll definitely need the correct sender and wiring for the aftermarket gauge(s).