Hello, new guy on the block with a question about my A/C on my ‘99 Lightning.

I’ve had this issue for a while but it only happened in a blue moon, first off, I could be driving on the Hwy usually around 75 and all of the sudden my A/C would start blowing out hot air but after a few mins it would start working again. Well as it turned out at that time my mechanic found a wire loose on the fuse or wiring block over the dryer? I’m sorry my mind isn’t thinking the proper names at the moment. Anyway he would tighten it and it seamed like the problem was fixed, for a little anyway until that wire came loose again, well after a couple of time of it doing that it put some locktight On the threads and not another problem until recently. Well to add some more information to this, I also started having battery issues, (dead battery) and would have to jump or charge it.
Well took it to interstate Batteries where I bought the battery an they kept trying to tell me that it was my aftermarket alternator and not the battery perhaps because they didn’t want to give me another one so after doing some self diagnostic IE start the truck remove the positive cable from battery and see if it still runs and well no issues it still ran without the battery. Ok next step went today and bought a new battery an optima yellow top deep cycle because of aftermarket equipment on my truck. Im telling you about this because it may or may not have anything to do with my A/C.
Now Back to the A/C Ill give two examples. 1st example, I’m driving mostly in the neighborhood and we have a few bridges around here. I’m driving at the proper speed and when beginning climb over the bridge ill give just enough gas to maintain speed and my A/C will start to blow hot air until I reach the top and descend, mind you this isn’t a tall over pass, its maybe 14 foot tall.
2nd example. I can be on the Hwy and I do have a lead foot mind you, so ill be doing on average about 80mph, and come across a typical lane regulator in the fast lane so Ill punch it, to go around them and all of the sudden, my entire A/C system will shut down including the blower. Once I let off the gas and return to MY normal speed the A/C is working again.
One more thing I can go out and start it sometimes and no cold air, turn off the switches and turn switches back on and it starts to cool. I have also had to turn off engine and restart and it will start working.

going to also submit a photo for identification, two things I need to know because I have had trouble trying to find the info but is the service port on my truck located behind this photo? Also look at the photo, does it look like a wire is missing of of that rely I believe that’s a rely. My memory is getting really bad these days and I’m having trouble identifying things. Could be age catching up could be al the pain meds I take. Any info would really be appreciated.

 

The folks that know about this sort of thing don't usually frequent the "New Member Introductions" forum. You might want to post in the "1997 - 2003 F150" forum to get some answers flowing.

Welcome aboard!

 

Moved to appropriate forum