A\C on, soft popping behind the console?

[Kenny_Z]

Normally I have the radio on so I don't hear this but today my brother and I were in the car and I could hear a soft popping every few seconds behind the console. It was only on with the AC running. I don't recall hearing that last summer but I hadn't been into the console area yet. Did I break something?

[jawn101]

Normally I have the radio on so I don't hear this but today my brother and I were in the car and I could hear a soft popping every few seconds behind the console. It was only on with the AC running. I don't recall hearing that last summer but I hadn't been into the console area yet. Did I break something?

Could be the A/C and fan relays cycling... are you sure it was from in front of you and not from the relay compartment?

Every few seconds is pretty frequent for that to cycle though, is the A/C working well?

[DMCMW Dave]

Normally I have the radio on so I don't hear this but today my brother and I were in the car and I could hear a soft popping every few seconds behind the console. It was only on with the AC running. I don't recall hearing that last summer but I hadn't been into the console area yet. Did I break something?

Compressor cycling, you are probably hearing the fan relay.

[Bitsyncmaster]

The low pressure switch makes a click sound when it opens.

But it sounds like you are low on freon if it's every few seconds.

[David T]

It could also be the cooling fan circuit breaker. You should check to make sure you have the relay upgrade kit. If it is just the fan relay, you may be cycling a little too fast. That would be a sign that you are a little low on refrigerant.
David Teitelbaum

The low pressure switch makes a click sound when it opens.

But it sounds like you are low on freon if it's every few seconds.

[Kenny_Z]

It's definitely behind the console, it is louder there when I put my ear up to it. The previous owner put in a fan relay kit that seems to be functioning properly.

The AC is not as cool as it was last year. I noticed that when the popping lessened after driving for awhile today the ac blew colder. Looks like she's going back into the AC shop for awhile. Thanks guys, I appreciate the help.

[David T]

If "behind the console" you mean the center of the dash behind the interior comfort controls and radio, there is not supposed to be any relay there. It must be something added by a DPO. Overly fast cycling will definitely reduce the cooling capacity. My previous post referred to the fuseblock area behind the rear passenger seat.
David Teitelbaum

It's definitely behind the console, it is louder there when I put my ear up to it. The previous owner put in a fan relay kit that seems to be functioning properly.

The AC is not as cool as it was last year. I noticed that when the popping lessened after driving for awhile today the ac blew colder. Looks like she's going back into the AC shop for awhile. Thanks guys, I appreciate the help.

[Kenny_Z]

There's no relay back there. I never saw one when I took it apart. The sound is definintely coming from behind the comfort controls below the radio though. It's not a click like a relay, it's a soft popping much like an air bladder that's got a low pressure release valve. You can mimic the sound by saying "poff." I'd take a recording but my phone doesn't pick up the sound.

[jawn101]

Do you feel hot air coming out near your feet while the A/C is on? You may be the victim of an old piece of foam (called a "tube seal") at the rear of the heater box, between the heater box and the firewall. If you lay on your back in the driver's footwell, reach to the right of the accelerator pedal. Feel along the center of the heater box between it and the firewall (more or less in line with the A/C mode switch) for either a piece of dried up old foam, or if the foam is completely deteriorated, a hole in the heater box. That foam is meant to fill the hole. Not entirely sure what the hole is for, but the recommended fix is to slap a piece of duct tape over it. The noise you hear may be that foam flapping around.

The seal is #19 on this diagram http://store.delorean.com/c-302-7-1-1-heater.aspx but is shown in the incorrect location. It's right in the center of the heater box, on the back side.

[Kenny_Z]

I'll take a look tomorrow morning before work. I was going through the online store in DMCH looking at diagrams of the AC system. Is it possible I have a vacuum leak and what I'm hearing is the diaphragm popping back to place?