electrical problems. help!
 

so after installing my oil pressure gauge. i went to start my truck ran fine everything worked good until i went over some bumps. everytime i did my radio, headlights, and gauge lights turned off.. parked it. went to start it the next morning.. just cranked over and never started . i noticed the voltage gauge was reading low. came back at night. and it started up just fine? but i whenever i went over bumps the lights kept flickering back on and off. finally i parked it when to start it today.. voltage was lower than usual. cranked it over and wouldnt turn on. then i could see smoke coming from the engine bay.. not from the starter tho.. maybe a relay?

ive had a problem with the external regulator before but with high voltage.. now its with low voltage?

its a 1990 dodge cummins 4x4 non intercooled automatic. anyone have any idea? thanks

Check all your wiring that you installed with the gauge, then all the wiring around what you did you could have moved something that is now grounding out.

I'd look at your battery connections if you disconnected them. I'd check them anyway.

Tim