1984 Camaro 305 c.i. - I just completed a swap of my idiot lights for an instrument cluster. I changed the oil pressure switch and that worked out o.k.

For the temperature gauge and the idiot light sensor, both the dealership and NAPA show only one part number - so that means that I should be able to run the same sensor - correct?

When I turn the iginition switch forward, the needle does jump a tiny bit - a show that it is energized - I guess. When I go all the way forward with the ignition key, to start the car, the temperature needle maxes out to the highest reading, then moves quickly back to just below the 100 deg. mark once I let off the starter - is that normal? It does not seem normal.

I have let the car warm up, and get very hot, but the temperature needle does not move. My sensor is on the thermostat housing and it has the round pin connection with a snap-together coupling that you just squish to disconnect. I'm wondering for all cars originally equipped with gauges that since the sensor was located elsewhere, if that would make any difference. Or maybe for service did they combine sensors somehow and now the servce part will work on both?

As you can tell, I am lost on this one folks..... someone, please bail me out!!!!

Thanks a lot,
Boomer

 

The temp gauge sensor is in the drivers side cylinder head, between plugs one and three. (in all thirdgens)

The one you are looking at is the coolant temp sensor for the ECM.

 

The behavior you describe when you start it is normal. It's sort of the equivalent of the "bulb check" function of an idiot light.

The gauge and light senders are in fact different... the gauge one is a variable resistance, the light one is a switch.

The temp gauge sender is between the #1 and #3 spar plugs, in the side of the head like Brent said. If it is still the one for an idiot light, then as long as the motor is below the temp at which the light turns on, the gauge will read stone cold. But as soon as it reaches the temp where the light would turn on, it will slam up to full scale. So it sounds to me like all is as it should be, you just need to get the right sending unit.

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"So many Mustangs, so little time..."
ICON Motorsports

 

yep it's normal and always bugged the hell out of me

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ICON Motorsports

1st & 3rd

 

O.K. Brent & RB - mission completed!!! It really helps if you know where to look - (duh) I fell like a dimwit. I changed the sensor over last nite. Looks like the functionality of the gauge/light sensors has been combined to one type. Works like a charm - you guys are great!

At this point, the chances are pretty small that I will be able to give back to the site what I have benefitted so far. Motorcycles, nows there's a subject I could help with, hey wait a mintute this ain't no ......

ede - I'm with you - a bad design with the needle pegging like that - thatnks for letting me know that it's "supposed" to be that way....

Thanks again guys,
Boomer