Sorry this is soo long,,,

About an hour ago I was going to go to a friends house, turned my truck on for a bit to warm it up(its about 45 degrees here), got in put it in park and 15 yards later it turns off, turns right back on but when I shift to park the engine loses power, the lights dim and the engine struggles to stay on, it stays on but you can barley hear the engine, the engine is really soft and struggles, the goes off.

It turnes right up though, here is what I noticed, when I turn it back on and rev up the engine, the oil preasure goes up to about 70 psi, and the battery guage goes up and down from like 11 to 14 volts. When I can actually drive it the oil preassure stays at like 60 psi, and goes up and down depending on how fast I go. SO I WAS WONDERING, what causes there to be high oil preasure? I checked the oil and it is a little on the low side. ALSO, this truck has spent most of its life at low sea level, I live way up in the mountains, could that cause something too?

Thanks

 

It kinda sounds like an electrical problem, get the alternator test, I think that might be your problem. The needle should be just over the 14 volts without fluctuating. If alternator test out ok, check your battery post and check all of the fuses on your truck.

When you say low sea level, did the truck from the coast line where it came into contact with salt water spray a lot?