Need help with water temperature gauge

[dacobb]

Originally Posted by RockBit

Dan:

I will call Doug next but I was hoping someone would get me going this weekend.

Thanks,

Sounds like you have a helluva cooling system.

Specs?

[jhv48]

Did you recently replace the gauge and sending unit or is this a problem that just cropped up? Possibly a dumb question, but if you did replace the gauge,did you pair up the electronic gauge with the correct sending unit? If so, then you might have a faulty sending unit.
When I wired mine, I ran the hot lead to a switched terminal on the fuse box, the ground wire to a grounded bolt, the lead wire to the sending unit and the last wire is connected to the dash lights.
The sending unit could also be sitting in/surrounded by an air bubble as mentioned. With the engine running, slowly loosen the sending unit a little until coolant runs out, then tighten it back up. That will ensure there is no air caught in the passage. If still no reading, call Nisonger and replace the sending unit.

[patrickt]

And if you have the Smiths BT2240-00C I'm pretty sure it has to be fed by a voltage stabilizer. So, that means one of the feeds is going to have to be the regulated ten volts (not twelve), another lead is going to be your ground, a third lead will be the 12v rheostat controlled feed for the lights. And then there's the feed to the sender. What I would first do is put a VOM on the wires and see if one of them was feeding me ten volts when I know the battery is 12.6 volts. Then I would disconnect the wire at the sender on the intake manifold and run a direct wire from the sending unit up over the windshield and in to the cockpit and see if I could get the gauge to respond using that 10v feed and the short cut wire to the sending unit (with the engine hot, of course). If you can, and you have the lights already working, then I would trace the leftover wires in the harness to see which one connects up to the sender, since I can make it work with the shortcut wire. Maybe the whole problem is there is no connection between the sender and the gauge. But, I have all mechanical Smiths gauges... they're pretty easy to wire up.

[RockBit]

Originally Posted by jhv48

Did you recently replace the gauge and sending unit or is this a problem that just cropped up? Possibly a dumb question, but if you did replace the gauge,did you pair up the electronic gauge with the correct sending unit? If so, then you might have a faulty sending unit.
When I wired mine, I ran the hot lead to a switched terminal on the fuse box, the ground wire to a grounded bolt, the lead wire to the sending unit and the last wire is connected to the dash lights.
The sending unit could also be sitting in/surrounded by an air bubble as mentioned. With the engine running, slowly loosen the sending unit a little until coolant runs out, then tighten it back up. That will ensure there is no air caught in the passage. If still no reading, call Nisonger and replace the sending unit.

Everything is new and supplied by ERA with the car. I checked to make sure the thread compound I used on the sending unit is conductive. I will try to burp the system as you suggest to be sure there is no air pocket. Thanks for the tip.