[knight hawk]

I think I have a falty temp gage sender, what do I get to replace it with ?...."55 T - Bird , converted to 12 volts, original 6 volt gage, with inline runtz ressister. gage goes too quickly to 'hot' , as if it 's not enough ground( if I ground the wire to the sender, it reads cold )

 

[boothboy]

Wire off, needle pegs full hot, wire grounded needle pegs full cold. If so try replacing the sending unit.
BB

 

[knight hawk]

I also think the sender is bad, but, according th to the Thunderbird parts books, the new original sender is $75 !!!!!!! I'm thinking, there should be one at NAPA or Autozone alot cheaper ???????????

 

[vicrod]

more info

Did the gauge work correctly after conversion to 12 volt and later started to act up?

vicrod

 

[knight hawk]

not really , when the owner brought the car to me, it was still on 6 volts, he said then that the gage wasn't working. I think This car was put together by a ' farm boy' in Iowa. He had been using a 12 volt battery from in the trunk, but sold it to this guy with a 6 volt under the hood,,,,I just spent 4 weeks fixing what he didn't, also what he did wrong ! It wasn't safe to drive ! Anyway, no, the gage did not work then either.....thanks

 

[vicrod]

test the gauge

The dash gauge has (2) internal magnetic coils that cause the needle to deflect from 100* at the lowest to 180* at midrange to 212* at the high reading.
First test the dash gauge:
Check to see is 6 volts is present at the gauge. The gauge must be grounded. 12 volts will ruin the gauge.
Disconnect the wire going to the engine sensor. The gauge must then read 100*.
If not the gauge is bad. If it does read 100* ground this wire. The gauge must then read 212* indicating the gauge is OK.
The engine sensor is therefore bad.

vicrod