Isn't '89 525 supposed to drop out AC compr on low vacuum?????

[Gene in NC]

hought '89 525, and all modern cars, was supposed to cut out AC compressor on low vacuum ie acceleration.

If that's not true, don't try to sell your M20 in AC season. That thing is a real power hog. Is there a simple module for control or is that an ecu function?

[Martin in Bellevue]

I think the compressor is switched off when the throttle position sensor sees wide open throttle. If you can generate the stomp test by depressing the throttle pedal 5 times quickly, with the key in position 2 & motor off, then the tps senses wot.

[Alexlind123]

Not all modern cars cut out the A.C. upon acceleration. I know of several cars built after '89 that dont have this feature you are speaking of.

[Gene in NC]

Alex, I respect your report but suspect that those that don't have it prob need it the most. Eg, low cost, low power, small cars.

[winfred]

leave rec on and turn off compressor when you need to pass, or grow some hp :D ahhh the trip home this evening in the e34, cruise set 10 over, outside temp reading 97* air temp at center vent 39* and for some strange reason not much traffic, weee weee weee all the way home

[Gene in NC]

Only one prob, I was about to be run over from behind in a modestly agressive merge in a 45mph zone. Had been conditioned in that exact merge by a '97 Ford Explorer 5.0 v8 and also a '97 Jeep 4.0 straight six that I had been testing for my son, both of which had plenty of pop.

Nothing wrong with my '89 525 5s except that I underestimated amount of throttle required and there was no oppty to cut off the AC. That's what BMW engineering was supposed to design in. If Martin is right, and I suspect that he may well be, the design is NG.

Need a vac controlled module to cut b+ to AC clutch at something far short of WOT. The temp control is turning the AC off and on all the time anyway.

By grab, think I'll just rig up a vac controlled AC clutch cut-off. How bout an adjustable module?

[winfred]

theres no vacuum in the hvac system on the e34, thank god, vacuum controls suck if you really want to be miserable buy a mercedes and deal with electric over vacuum over electric over vacuum controls, no i didn't studder it's that bad on some models

[Gene in NC]

Why only cut out AC compressor on WOT?

[winfred]

foot to floor max acceleration without the drag of the ac


Why only cut out AC compressor on WOT?