A/C really stumping me

[camlbi]

So this weekend I did some work on this guys 90 TT I know my way around this car well but this ac is really stumping me.
The compressor was not turning on when the climate cntrl was turned on so I checked the pressure in the system it was fully charged. Then I jumped the compressor clutch to turn it on. Even w a full charge thhe ac did not blow cold the high pressure line felt slightly cooler but not much. Could it be the dryer or could something be clogged??????

[NolimitZ32]

What did you use to check if the system was full?

[camlbi]

I have a set of guages

[NolimitZ32]

K, just making sure, because some people use the filler gauges off those autozone kits and those don't tell you s***. I'm willing to bet its the expansion valve, had pretty much the same thing happen in my WRX. jump the Compressor switch it blows cool for a few min then stops.

[marty1mc]

Is your condensor fan working?

[camlbi]

No the condencer fan does not kick on ....where would I find said expansion valve?

[NolimitZ32]

not sure never dealt with AC issues on a Z32, check the FSM, i'm thinkning somewhere under the dash

[es.biggs]

What do the gauges read when the system has been off for a few hours? And what do they read when you have the AC system "on"?

You can usually tell if something is clogged by the pressure readings. And you definitely want your fan running, that is a major part of the condenser's job to remove heat.

[marty1mc]

No the condencer fan does not kick on ....where would I find said expansion valve?

OK, the condenser fan is critical for proper cooling. It keeps the pressures lower by cooling the newly compressed liquid. There is also a low pressure switch in the system that may have gone bad. This will keep the compressor from engaging when the pressure is too low and damaging it. I would check that switch first.

[fabbio25]

I had the same problem on my car and it turned out to be that the clutch on the compressor was bad. This is a common problem on our cars.

[marty1mc]

It's not the clutch. He was able to engage the compressor by a jumper on the clutch.

[A Paratroopers 300zx]

Just a friendly note... The expansion valve is located in a box under the dash next to the heater core on the passenger's side. The whole dash and cross member have to be removed to get to it. I would strongly recommend sourcing all other possible problems before looking at the expansion valve, as it is about a 10 hour job to replace.

[marty1mc]

Just a friendly note... The expansion valve is located in a box under the dash next to the heater core on the passenger's side. The whole dash and cross member have to be removed to get to it. I would strongly recommend sourcing all other possible problems before looking at the expansion valve, as it is about a 10 hour job to replace.

Actually, the box will come out by itself. Once you remove the glove box and its support brackets, discharge the system, crack open the system, remove the seal in the firewall it will pop right out. This was done intentionally to allow the system to be repaired.

But, the expansion valve can only keep the clutch from turning on if it leaks.

[A Paratroopers 300zx]

^^ Oh word... thanks for the clarification! I just figured it would be as difficult as the heater core because it's right next to it lol. That's good info for future use though