Turn headlights on and hvac and radio turn off

[bizzo15]

My brother just picked up a '92 Chevy K1500 and when he turns his headlights on the hvac and radio turn off has anyone else experienced this and know what the cause is? Also on a different but somewhat related note the hvac controls on my truck are messed up all of a sudden. I can't switch from hot to cold anymore anytime I try to all I get is a bunch of those little arrows flashing at the bottom of the screen. If that's not clear enough I'll take a pic and post it. I checked the fuse and it tested good so I'm not really sure what else to look for besides replacing the controls themself.

 

[bizzo15]

BUMP

nobody has had this issue before??

 

[///RAGMC]

Your having a grounding problem on your brothers truck On your truck I had the same problem you can un pluge the battery or hvac unit to reset it but what was wrong with my truck ended up being the the ac needed refrigerant

 

[bizzo15]

Ok thanks, I pulled the fuse on my truck but that didn't reset it. I'll try the battery next. I know I need refrigerant as my AC doesn't work but I don't really care to fix it either. It doesn't get too hot in the summer and I don't drive the truck constantly in the summer to make it worth the expense.