Coolant temp sender

[drummguy04]

I have a 2000 B3000 that's in great shape except for the coolant sender hasn't been showing up on the gauge. I've replaced the sender, I checked for power and it's getting 10.5V when the truck is on, when I run the cable to a ground the gauge spikes so it's not the gauge. There is continuity in the circuit, when I jump the plug and send it to ground I get continuity as well so the wiring is good. For some reason when it is plugged into the sender sensor it hangs out below cold on the gauge.

It worked yesterday when I grounded it to the cable that comes off the battery but now it's not working again. Anyone have any thoughts?

 

[Curious Hound]

You need to figure out why it's only getting 10.5 volts. Due to this pesky little law of physics called Ohm's Law, the voltage will affect the reading.

You're looking for a dirty or loose connection somewhere in the circuit that is creating resistance and lowering the voltage that the sender receives.

 

[alwaysFlOoReD]

Is it a one wire sensor? If so make sure that you haven't covered all the threads with Teflon tape. There needs metal to metal contact for a proper ground.

 

[drummguy04]

Is it a one wire sensor? If so make sure that you haven't covered all the threads with Teflon tape. There needs metal to metal contact for a proper ground.

It's a two wire. I was able to find a suitable ground and wire it. It's working but it's sluggish until the coolant really warms up.

 

[drummguy04]

You need to figure out why it's only getting 10.5 volts. Due to this pesky little law of physics called Ohm's Law, the voltage will affect the reading.

You're looking for a dirty or loose connection somewhere in the circuit that is creating resistance and lowering the voltage that the sender receives.

What is the proper voltage for it to be running at? I would guess it should be around 12V.