BobbySingh

While cruising on a highway. If headlights are turned ON the RPM suddenly goes high and when the lights are turned OFF the RPM goes low. I am not sure if anything is wrong with the truck or no. It does seem to consume more gas though. Does anyone have an answer??

Thanks

jerryp58

Do you think the engine RPM are actually changing or is it just the gauge?

Maybe a short between the headlight circuit and the tach? Mabye a bad ground?

Does RPM change if you leave the lights off, but turn on the A/C or air blower motor (or any other high electric load)? If so, then it may not be a wiring problem.

If the engine RPM actually rise, maybe you have an alternator problem. The extra draw on the alternator is causing the engine to try to rev it up to compensate. That could be causing increased gas consumption too.

__________________

Jerry
2004 Frontier, King Cab, XE, 4x1, 4-cyl, 5-spd
My Frontier Page

zimmer_kole

Good call Jerry, i would think it is a power issue.