Remote Air Conditioner Pump


Well-known member
Apr 27, 2022
After suffering the onset of heat stroke a couple times already I really want to get the A/C working again on my truck. I initially kept all of the stock components but never hooked them up and have battled compressor interference with the steering box since the motor swap. Seems there are numerous accessory layouts available for the LS platform but none for the 1uz/2uz/3uz motors. My best option is to delete the compressor which leads to my point, has anybody run an electric A/C pump in place of the mechanical one?

From limited research a few different types exists due to hybrid vehicles, semi sleeper cabs, and rear seat units for big SUVs. They draw up to 100amps continuous which would require an alternator upgrade but that is doable. I would be hooking up the stock evaporator core in the truck and ideally incorporating the stock controls. The condenser, dryer, and expansion valve could be swapped if needed.

Anybody have experience with this?
One of my customers just added an electric compressor to their tube chassis baja bug. When i inquired about it they said that it definitely made a difference for them and kept them cooler, but by no means were they cold. Mind you this was also about 8 weeks ago in Johnson Valley in a tube chassis car with a cut up shell set it on and some aluminum panels to “seal” the cabin area, so I’d call it a win.
That's encouraging. I have a fairly well sealed cab and would definitely step up my insulation game at the same time.
So something to consider with that big of a draw... Could you run a second alternator and run them 'in line'?

The reason I ask is because I was talking to my buddy John at Agile about their power draw on the Sprinters that are all built out. He said that he was actually losing about 15hp from their alternator because of how much they draw... So he had an alternator cut off switch for the vans for when they were driving up big hills in like Colorado or driving up the Mammoth grade.

So if you had a second alternator built in just for the AC you could just turn it off during the winters.

But maybe just running a big alternator would do the same thing???
The electric ac compressors are the way to go! I have been wanting to put on in my truck and my Subaru for years. We have an electric car (Chevy Bolt) and I absolutely love that little car. The ac kicks ass. I think years ago VW was putting electric compressors on gas engine cars, but they are a must with EV's.
The nice thing about alternators is they self regulate according to the draw so they would rob less power when battery voltage is at it's peak. Some of these compressors also look like they throttle up with fan speed so you could turn it down on hills and stay cool. Mechanical compressors are either on or off so you can definitely feel the power loss.

Search results report 1hp for every 23 amps so about 4hp for my stock alternator and an additional 4hp for an electric compressor. Google shows dyno runs reporting up to 10hp loss with mechanical compressors so it may be about the same. Honestly though if I'm in a cold truck I can take a bit more time getting through the desert and not worry.

I just thought it was a cool idea that they came up with. Wasn't sure how relevant it'd be to the trucks.

I think they do it more so because they are always charging the lithium batteries which take as much power as it'll give them so until they are topped off the alternator is giving it everything it's got. (regulated of course)
Lithium power banks would make sense, I couldn't figure out what they would actively be using that drew much but recharging from the night before would do it. Unless I pull a Los and bump till the break of dawn I should be good.
I have a buddy who was looking into this for his car with limited motor space. He shyed away from it because he stated that all the compressors were either 110 or 220 and took 100 or more amps which would require a high output battery and inverter, alternator etc.
That compressors above is it 12 v? Can u post a link to compressors u are looking at. Any info on this subject intrigues me. Lol
Other thing you need to match the compressor to the system. Too big on your stock system and it will have issues pulling the low side down too fast with high discharge pressures. Too small, you don’t get much cooling due to not enough suction on the low and not enough discharge. How to spec this? I don’t know.

The other issue is when the compressor kicks on, you will have a spike, then a slow increase of amperage as condenser temps increase from outside temps or compressor demand. So if it runs 100amps continuous, that’s a lot on an alternator. Typically the battery is your buffer in the system, you may need to run 2 total because the alternator is going to be putting out under 100amps at idle or low rpm. This is assuming a 160amp alternator. Now you can go a custom one but now we are getting away from simplicity and “off the shelf parts”.

Alot of these hybrids run off the big ass battery packs so it’s far easier to make them work