'93 960 sedan A/C, ventilation cuts out on acceleration

mrfixer · Post by **mrfixer** » 20 Apr 2005, 13:54

My A/C , ventilation cuts out during acceleration - comes back on when I let up on accelerator to cruise. A/C works fine otherwise. Is this a quirk of the auto climate control system? Could I have a vacuum leak or loss of vacuum to the climate control system during acceleration?

George Vrionis · Post by **George Vrionis** » 20 Apr 2005, 22:11

Hi

I get the same thing on my 740 wagon. When you accelerate harder or go up hill it seams like the a/c is cutting out. What in fact happens is that from head vents it splits to head/foot vents and it seams like it is cutting out but isn't.

It could have something to do with the vacuum system but I'm also unsure whether it is a quirk of the system or not.

if you found out, post it.

Cheers and good luck

George

LaRy · Post by **LaRy** » 21 Apr 2005, 11:48

I am not an expert in AC, but I have a theory. The vacuum is coming from the intake of the engine. The more open the throttle is, the less vacuum you get. That is a fact. Maybe the vacuum is to small to keep the the vacuum pistons for the airflow in expected position.
I have some similar problems with low vacuum in my 740 for the cruise control I installed afterwards (not origin). I had to build a canister to keep the vacuum when driving uphill, the vacuum was to weak to increase the throttle.

mrfixer · Post by **mrfixer** » 22 Apr 2005, 21:31

Thanks for the replies. I kind of figured the vents were splitting from the uppers to the lowers due to a quirk in the system and I know that when an engine accelerates, the vacuum drops to almost nothing. In an automatic climate controlled A/C & vent system, the loss of vacuum to the controls would almost shut everything down or at the least cause some vents to close. Glad to hear I'm not the only one who's experienced this! Thanks again!