Hello, Newbie Here... Just replaced my alternator on my 97 F150, 5.4 triton. All went easy but now my gauges are erratic. With cool engine at start up they go to "normal" positions but after a couple minutes the Temp gauge goes totally high, Oil Pressure reads low and voltimeter goes low and then fluctuates sometimes raising with higher rpm. Any ideas here?

 

Sounds like a loose connection or poor ground. Re-check everything you touched and make sure they are tight including the battery terminals and wiring.

 

usually a battery and an alternator go at the same time, one destroys the other and is best to replace them both,...