A/C cuts off on hard acceleration and wont come back on

[chefjames333]

I have a 97 960. The A/C works perfect at normal driving. When I go onto the expressway and speed up fast, the A/C stops cooling. I have to turn everything off and wait 2 mins and then turn back on. Then it works great again. Can't figure the problem and dont have a volvo mech except the dealer. I dont want to pay $500 for them to fix. I know the A/C kicks out to help with accelerating on some cars and assume volvo's do it to. It just does'nt come back on. I am mechanically inclined so the repair should be not problem. I just need advice on what to try.

Any help appreciated
James

[billofdurham]

I know the A/C kicks out to help with accelerating on some cars and assume volvo's do it to.

They do but, as you say, it should come on once the hard acceleration is finished.

You could have a vacuum problem. Start by checking the vacuum supply hose in the engine compartment. The vacuum hose for the A/C-heater can be found under the intake near the transmission dipstick tube. Look for a 1/8" diameter white plastic hose. It goes from the bulkhead (firewall) near heater hoses and winds its way to a tee with a check valve conected to a larger hose, ending at the intake. It is common for the hose to rub through from chafing on other hoses or wiring harnesses. If there is a leak cut the hose and splice with a small piece of rubber vacuum hose.

If that doesn't show a problem then it is possible that there is a leak under the dash or it may be that some foreign body is obstructing the flaps. To check this you need to get your arm up into the air intake that goes up behind the glove box. You may be able to feel bits of paper or other lightweight bits and pieces that have been drawn into the system and are stopping the flaps closing. You may hear the vacuum motors hissing as they try to close the flaps.

Failing that you may have a problem with the flap control solenoid. There is a write up of the repair for this courtesy of Dick Riess on Swedishbricks:
http://www.swedishbricks.net/700900FAQ/ ... #Replacing Vacuum Servos in ACC-Equipped 700/900

Bill.

[chefjames333]

Thanks so much. I will check this today and post the diagnosis.

James
97/960