Hi guys,

I have an LS1 V-8 conversion, and I'm using the console oil temp. gauge for coolant temp. instead. My problem is that when it's running at normal temperatures, the needle is at about 9/10ths, just short of the red region on the gauge face.

I'd like it to be at about 2/3rds. Is it as simple as putting a resistor between the sensor and gauge, and how would I figure out the value of such a resistor? An adjustable pot?

Thanks!!

I've been thinking about something similar for my V6 build. If I understand it correctly - if you can get the range of values for the stock gauge, whether its voltage or impedence, and corresponding temps you should be able to map it to the new desired values. From there you can derive a shift in volt/impedence and calulate the resistor.

That's the theory anyway. I'm still collecting sensor data for mine.

Remove your coolant sensor and put him into boiling water. So you have 100 degrees Celsius and with an potentiometer you can adjust your gauge as you want.
If finishes you ca measure with an ohmmeter wich resistor you need.

The best way is to use the sending unit that matches the gauge. The resister is series
will not report the correct temperature all the time.

Thanks, guys. I'll get a pot from the electronics store, experiment, and get back to you. I'm not sure if the "perfect" temperature sender exists for this application and the original gauge.

Send the gauge to Hollywood Speedometer and give them the sensor values. They can re-calibrate the gauge for you.

Yes.The way I did mine:
Go to Eguages or an equivalent.Buy the correct sender for your LS(VDO style)
I used the 120 deg sender,and bought the vdo temp guage (part#310-105)
Wiring is dead simple. The stock plug fits perfectly.You have to swap 2 wires in the stock plug,the power and the sending leads.Thats it for the stock plug.The back light requires a ground(cause the new vdo has a plastic housing)I ran a ground lead to the nearest under dash location(Stock bolt) and done.
Almost.
The guage is smaller than the ones in your console.The guage has a threaded plastic ring that is used to seat the guage up against the mounting hole.This helps with the diameter problem.Spin it on.Now the guage is closer to stock diameter.The rubber mount you pulled off your stock temp guage is useful here.
I tried to use it as is.Not a great fit.Take it and flip it inside-out.Viola!The whole assembly fits nice,and trims the guage face/retainer nicely.
Click to view attachment
And its tight as the rest. Needle is wrong color(or have the old ones faded )but its not noticable while driving.It keeps temp perfectly.I have confirmed this with a temp gun repeatedly.
Its a nice solution.It also(with a minor modification)fits the stock harness and location,and doesnt look out of place.
It comes with 2 filters for the backlight.The green one is perfect.
hope this helps!

Thanks for posting. That's a nice solution, but I think I want to retain the stock gauge. On the advice of previous poster, I went to the Hollywood Speedometer site, and I think they can do what I want. I'm gonna get the reading of the sensor in ohms when the first fan kicks on, supply them with that info, and have them adjust the gauge to read 2/3rds at that point. They can re-do the face to add acutal temps, but I'm fine without that.

The gauge works fine as is; it's just hard psychologically to have the needle so near the red when it's at normal operating temp.