Car: 92 UK spec 300 tt with auto air con

 

Since my car is off the road with a dead turbo I went out this morning to check out the problems with the air con.

 

There is a loud ticking noise coming from the auto amp but this goes away when warm air temp is selected and returns when set back to cold air. The air con pump clutch is not engaging and I have checked all the fuses. Could it be that the auto amp clicking is an indication that it has failed or is the noise the result of it trying to operate the pump but unable to do so due to another fault, perhaps the air con relay?

 

I have read that the pump will not engage if the system is low on gas, and although I have checked the sight glass its hard to be sure, but in this case I would expect the system to know this and not attempt to run the pump.

 

I am no expert on this and am only guessing, has any body ever experienced similar problems, as this is the sort of job that you could end up replacing everything in the hope that you get lucky.

 

I looked at the self-diagnostic info but got lost in the technical jargon, most of it does not seem relevant since everything else seems to work fine.

 

If anyone has a spare air con relay or amp for sale please let me know. Not sure if jap spec is the same as uk though.

 

 

Steve.

 

Also have an air con question (sorry steve!)

 

As lacking an owners manual, why is amb temperature always 15-17 degrees - constantly blowing hot air into car even when off?

 

Can air con jut be off - no air, or does it have to blow something? If so can it be adjusted?

cheers

Robb

 

Steve, could be a short in the system somewhere..

Maybe a stupid question, but have you checked whether the belt for the aircon is still there ?

 

Robb, amb-temp should vary...could be that your ambient-sensor is gone, disconnected or broken.

The ambient-sensor is usually attached to the front-bumper near the license-plate.

 

-Eric

 

 

recently had a new front bumper, so what am I looking for (me not very car technical!)

 

did read 10 deg once when v cold but as I said usually 15-17

 

Is amb temp the outside temp?

 

Robb

Robb, Ambient-temp = outside temp.

When they replaced your bumper they probably forgot about the sensor (happens very often)..and now it's still connected to your old bumper somewhere.

 

The sensor itself is quite small and is connected to a thin electrical wire.

 

-Eric

 

Steve, could be a dry joint on the board of the air con unit. Sounds like a relay is opening then closing. There is quite a lot of heat build up under the cover board down there and this could, over time, cause dry joints on circuit boards. Have you taken the unit apart to check the soldered joints or not????

 

CheerZ,

 

Andy

looked behind front bumper and found a thin white wire with a connecter split from it hanging about doing nothing - take it this is the wire in question?

If so where (or does anyone have a spare from a car being broke) can I get an ambient sensor from?

Cheers Robb

Thanks for the replies..

 

I have checked the belt, seems ok. I agree it sounds like a relay opening and closing, I will attempt to open it up and have a look.

 

Steve.

or are there any companies that sell these?

Nissan partnr for the amb-sensor is 27722-31P00 (

or you could try a breaker

 

It's probably just a simple NTC though, but one that has a very special (and expensive) Nissan label

 

-Eric