[Peterbilt387X]

I just hooked up my boost and pyrometer gauges from Autometer. The EGT had 3 wires - ground, 12V constant, 12V on/off...the 12V constant runs the actual gauge/probe I assume. Will this constant 12V kill my battery? I turned my truck off and my EGT gauge was still registering 250. Hopefully someone replies soon or I may have a dead truck in the mornin! lol

 

[chuckster57]

I think you did it wrong

Did you install "electric" gauges? If so the 12VDC "constant" they are refering to is a 12VDC source that is on in the "run" and "start" position. Not a constant (all the time) hot.

What series are you using?

 

[Peterbilt387X]

I have Autometer Ford Factory Match gauges. The boost is mechanical but the EGT is electric sweep. I used an "Add-a-Circuit" (fusebox double plug) on a fuse spot that registered 12V while the key was off.

 

[chuckster57]

When I did my buddies PSD, we used the add a circuit and used the ECM fuse I think. The gauge needs power when you turn the truck on and start. When you turn the key off the needle will stay at what ever it was reading at that time. The next time you turn the key to "on" the gauge will cycle and then read the present temp. Only should have power when the key is on but also in "start".