Been meaning to ask this one for awhile. I know some cars will cycle the AC compressor when the A/C is NOT set to "on" and the heater is going to help remove humidity from the air and prevent window fogging. But being a 95' with a manual climate control center, w/o the winter package, I was surprised to see this happening almost constantly with the heat running as it's hurting MPG and robbing some HP. The compressor is cycling on......off......on. Normal? Or do I have a bad sensor somewhere?

 

 

Also, both fans are kicking at the same time with the heater running, which is redundant in colder weather. Engine is NOT overheating and always stays at the 1/2 mark, which takes about 10 minutes or so to reach from a cold start. I suspect this is because the A/C compressor kicking on.

 

All this sound normal? Only solution I have at the moment is to disconnect the A/C compressor "on" wire right at the compressor to stop the compressor from forcing on. I've tried turning the heater recirculation button OFF thinking it was linked to that as usually that feature is tied into preventing window fog, but it didn't affect the compressor.

Edited November 15, 201411 yr by Bushwick

If you are set on the Defrost/windshield and heat, yes it's normal.

If you are set on the Defrost/windshield and heat, yes it's normal.

 Thanks. That's where it's usually set. Guess I'll leave the compressor disconnected then during the winter to prevent the extra MPG or Idle per gallon drain. Just need to remember to plug it back in every so often to keep the compressor clutch happy

before you go to that trouble,

try just using the windshield / floor position.

i don't think the AC comes on then.

 

but that's easy to check.

Edited November 15, 201411 yr by johnceggleston

Thanks for the tip John. To be honest, I don't use the floor setting plus I have a tweeter amplifier under the seat that would get too hot if I did. Suppose I could block the under-the-seat floor ducting, but the defrost is always on anyways. The plug takes 2 seconds to unclip and lets the defroster run w/o the rapid on/off of the fans and AC. Last year I didn't have the AC working and the belt was pulled, so none of this was realized. No biggie.

 

Main reasoning for the question was to make sure their wasn't some A/C pressure switch going wonky or something funky with the climate control. I don't mind unplugging as 130 CHP - 40 CHP (4EAT ) - another 5hp for the A/C kicking on is too much 

It's a good idea to keep the AC working all year long so the seals don't dry out.

The heater vent on the floor will not overheat the amp under the seat.

If that's happening, you're asking way too much of that amp.

 

Just use the defrost/floor mode.

The heater vent on the floor will not overheat the amp under the seat.

If that's happening, you're asking way too much of that amp.

 

Just use the defrost/floor mode.

 

The heat coming from the dash vents is enough to make my hand uncomfortable 5" away like scalding water. My tweeter amp is an older class "T" amplifier Blaupunkt PA2150 that borders on rare as they were made in a short run, not in it's plastic case. Any heat getting thrown directly onto it can/will cause issues like wearing the caps out prematurely and can quite possibly fool the internal temp sensors to shut it off if it thinks it's running hotter than it really it is. Class "T"  is basically a hybrid of class A-like sound quality, with a class D-like power supply. It's technically an inexpensive amp, but not easy to find one someone didn't toast trying to run subs at wrong impedance. Did I mention it fits perfectly under the seat

It's a good idea to keep the AC working all year long so the seals don't dry out.

 

 

 Just need to remember to plug it back in every so often to keep the compressor clutch happy