A/C and Recirc buttons don't work

[rcspencer1]

'92 525i - I know it's below 33 degrees outside, but for some reason both the A/C and recircl buttons don't light up and, I assume, aren't working. The rear defog light (just above the other 2) does work, so I'm confused. Any ideas on what might be wrong? Thx for any help out there...

[Fetch]

Hmm, How long have the buttons not been working, I'm not much for troubleshooting HVAC systems, but here's what popped into my head:

Recirculate turns the A/C, and A/C obviously turns the A/C on, so possibly you have a refrigerant leak, and when the system gets low enough on refrigerant, the compressor won't turn on (to save itself from damage).

It might be worth checking out.

Also of course, there will be relays, wires, etc....yikes... ;)
Good luck, hopefully somebody else has more insight!

[DaveVoorhis]

I believe (but can't say for sure) that it is standard operating procedure, since about 1992 or so, for the A/C system to not enable either the recirculate or the A/C lights if the static refrigerant pressure is too low.

Mine don't light, but I know for a fact my refrigerant pressure is zero, having been extracted by the prior owner. Curiously, they will light for a second or two after the battery has been reconnected after it's been disconnected. I suspect it takes a second or two for the A/C system to check the static pressure.

[rcspencer1]

Thanks for the replies, guys. I really suspect that it is a low refrigerant problem and will have it checked out...once it gets a bit warmer here in Boston!


I believe (but can't say for sure) that it is standard operating procedure, since about 1992 or so, for the A/C system to not enable either the recirculate or the A/C lights if the static refrigerant pressure is too low.

Mine don't light, but I know for a fact my refrigerant pressure is zero, having been extracted by the prior owner. Curiously, they will light for a second or two after the battery has been reconnected after it's been disconnected. I suspect it takes a second or two for the A/C system to check the static pressure.