My truck is to high - Cars & Co 1976 Ford Gran Torino "Starsky Hutch" 118 Diecast Car

It is likely a blown high beam fuse - check your fuse box. Or it could be the high beam relay - but I would check the fuse first

Define idles high like its going high rpms before shifting or the engine itself is high reving if its high rpming when shifting its mostly you tranny going out you can try tranny fix oil I used it on my truck when it had shifting problems and ive had no problems since it takes a few days to work though and if its the motor itself it could be a lot of things but I dont know much of the problem based on what you told us

name how high. is high. RATES?
keep in mind MPG varies by load , driver and tire pressure.

Change the high beam relay it has welded on

see fuse for the high beam

what valve? whats the history, was it recharged? is the condenser fan operating? what are the pressures? what is the ambient temperature?

high beam switch is faulty look at getting a new stalk.....

start truck leave in park press 2 wheel high button put truck in drive move truck,check for being in 2 wheel high, if still in 4 wheel low have switch and shift solenoid checked

High speed fans only come one for high temp or high a/c pressure. Will be hard to tell if they work on high.

usually due to high resistance causing high voltage. Check voltage at headlamp. should be between 12 & 14 volts.
check headlamp grounds. if loose or corroded, it will cause high current draw.