bad ground

[duramatt05]

Recently did headgaskets on my truck, got it all back together and everything running good, but I noticed that my pyrometer wasn't working. I noticed that it works when there are no lights, or any thing that takes power like windows blinkers, brakes. I've checked the power and ground for the pyrometer and it seems good. The backlights on the pyro and boost still work. If the headlights are on and I try to put the windows down or turn the blower motor on it pretty much kills the batterys. As soon as the windows are down it goes back to normal. I think I've got a bad ground somewhere, but any tips would be great.
Everything worked fine before I did the headgaskets.

 

[duramatt05]

anything?? i have the pyro hooked into the "seo accy" fuse in the cab. unhooked that and still have the problem.

 

[TDFDiesel]

Check all your grounds. You get the ground between the firewall and engine / frame reconnected? You might try adding a ground between frame and engine to see if it resolves any issues. Check battery terminals to make sure they're good on both sides. Check the main power wire to make sure it's tight.

I had a VSS issue on a car once because the power wire on the starter was loose.