[ZeGermanHam]

I'm in the final steps of wiring up my '66 before dropping in the engine and firing it up. Silly question... Can I connect the electrical connection for my stock water temp dummy light to the aftermarket temp sender that came with my electric AutoMeter water temp gauge, so there would be two wires going to ONE temp sending unit? Or do I need to run a separate stock sending unit for the factory dummy light in addition to the sending unit that came with my AutoMeter gauge?

Here is the sending unit that came with my AutoMeter gauge:


And here is a stock style temp sending unit:


Curious what people with electric gauges are doing and whether the aftermarket sender can be piggybacked to send the temp to both the dummy light and the auxiliary gauge.

["QUICK-SILVER"]

Sender for the dummy light is off or on. The gauge sender has variable resistance.

Need two different senders for this to work
Clay

[Goatracer1]

Your light would be on dim and get brighter as the temp goes up.

[ZeGermanHam]

Thanks guys. Makes sense.

[Brentco]

Yeah you need a second temp sender to run both gauges. Just put the second sender in the other port on the intake crossover. That’s the set up I have, because I wanted to keep my factory temp gauge and run an aftermarket one. I was concerned that all the sensors and wires would make my engine look like an ICU patient, but the one on the right is actually almost completely hidden by the distributor (at least in my set up) so it’s hardly noticeable.

[Formulabruce]

Originally Posted by Goatracer1

Your light would be on dim and get brighter as the temp goes up.

This was Very common at the Dealership I worked at. People would change them for whatever reason, and get a gauge sender, hook to the idiot light, and presto auto dim and auto bright Idiot light !
Parts stores didn't have specs and the on- off senders rarely went bad, and when they did it was an open , " no light".

[ZeGermanHam]

Originally Posted by Brentco

I was concerned that all the sensors and wires would make my engine look like an ICU patient, but the one on the right is actually almost completely hidden by the distributor (at least in my set up) so it’s hardly noticeable.

Yeah, that is my concern as well. I'm trying to streamline and conceal as much of the wiring as possible. I'll probably route the wires for the temp senders between the valley pan and underside of the intake.