Hello! New member here with a perplexing problem. It would take me forever to explain so I'll list all the symptoms and hopefully someone can guide me in the right direction. The car is an 02 Crown Vic. 406l v8


This problem happens only when the car fully warmed up:
1. The oil pressure gauge flutters wildy when the car is in gear and foot on the brake. If I take my foot off the brake or put the car in neutral or park the fluttering stops. Any ideas what is causing this?


Another problem is probably the alternator/voltage regulator. when I start the car and apply the brakes to put the car in gear the needle on the alt. gauge drops for a second and then returns to it's normal position. The lights dim for a second and then return to normal. The needle does the same thing when the car is put in gear.

I tested the battery with a multimeter and it showed 12.4v and 13.9v at idle. That number dropped to 13.7v when the lights, a/c, radio, etc. was turned on.


Thanks for any help any body can give me.

 

The connections at the battery may be OK , but it does seem like there is a possible poor connection in the system and that could be either battery positive or ground connection. Always a good idea to confirm all good ground connections before replacing anything.
You might check for voltage drop when the vehicle is placed in gear. Check at the engine and fuse panel and not at the battery . Never a good practice to do anything with vehicle in gear with the engine running and no one holding their foot on the brakes.