Have 51 miles on 70 Challenger after 15 year rebuild. Have 180 thermostat and after driving couple miles the temperature gauge does not go above the 1st white mark by cold. Check around water pump with temperature scan gun and it reads about 175. Should the gauge needle be up higher ? ?
thanks

I have had them read a bit different for each car and sensor you have in the block.

they usually have a bracketed area that it falls between for "normal" temps.

you could check the sensor or wiring, or even voltage to the gauge and see which might be off.

I would say YES. I didn't have a Challenger but I did have a brand new 69 Dart GTS back then. My temp gauge would always read right about 1/2 way/or right about in the middle of the gauge after the car was warmed up.

You did'nt state the engine size..Is the 180 stat the correct factory value for your engine ??? As other's have suggested it's a matter of matching all the new components together and seeing where "normal" falls on the gauge for a known given temp..

Were the gauges rebuilt ???

I think from the factory the car would have a 192 in it

Factory gage use factory sending unit, Auto meter use auto meter sending unit

Test the gauge (w/key off) by pulling the sending unit wire and grounding it. Turn key on and watch gauge, but don't let it peg too long! If it goes all the way to hot, your sending unit is bad/wrong. If it doesn't go all the way, gauge is bad. Assuming your other dash gauges are working, the dash voltage limiter is working correctly.

[quote=screamindriver]You did'nt state the engine size..Is the 180 stat the correct factory value for your engine ??? As other's have suggested it's a matter of matching all the new components together and seeing where "normal" falls on the gauge for a known given temp.. My 69 Dart was all stock, as I stated it was brand new with a 383 motor.

Were the gauges rebuilt ??? [/quotte]

My 69 Dart GTS was all stock back then, (it was brand new), with a 383 motor and 391 gears. Temp gauge needle always went to 1/2 way between cold & hot when engine was warmed up. I'm guessing yours should too if everything was in sink. I think all 70 Challengers came new with 195 stats.

Above post is where you need to start first....

It really doesn't matter what they read in the day.
it really is just a resistor. you have to figure out where you are different and change it so it reads where you want.

Voltage, sender, wiring and gauge are your variables. one or all might be off. Till you test you don't know.

Standard thermostadt in 1970 was a 190..

Just my $0.02...

Mine worked fine. Put a brand new motor in but used old water pump, sending unit, wiring etx and now it just goes to the first mark but doesnt fluctuate. I bought a new sending unit to plug in and hopefully that fixed the problem.

440 Magnum. Problem with adding resistor is I need less resistance to get needle to move farther. . Correct ? ? Have new sending unit,180 thermostat, have old sending unit maybe I can check resistance on that at 180 degrees.

yes, less resistance moves it further up the gauge face.

if you are referring to my post. I didn't mean add one, I meant the sending unit is one.
but things like the wiring, connectors can add resistance.
bulkhead connector and poor connections.

but also the dash VR giving less than 5 volts could cause issues.

things to check. a different sending unit could give different values too.