1995 940 AC Clutch not engaging

GESY940 · Post by **GESY940** » 16 Mar 2015, 23:00

Hello folks my AC Clutch is not engaging, who knows why.
I read many time that low Freon my cause this.
The question is how to I get the clutch to engage so
I can try to put some Freon and try charging?
Thanks......

Also, is there a relay or fuse for the AC in this
1995 940 Turbo wagon?

Thanks again !!!!!!!!

93Regina · Post by **93Regina** » 16 Mar 2015, 23:15

GESY940 wrote:AC Clutch is not engaging

Looking at 1994-940 schematics, I'd pull the connector at the dryer, and see if 12V power exists there, on one terminal. With engine on, and AC turned on, of course.

If so, take a paper-clip or something, and touch both terminals, for a quick moment.

GESY940 · Post by **GESY940** » 17 Mar 2015, 06:10

Thanks !!!!!! Will do that later "If not raining"

According to "MY" schematics there are 2 switches, but again
I had seen so many variations of the 940 that I want to be
sure with you folks, 10000 of thanks.

93Regina · Post by **93Regina** » 17 Mar 2015, 06:46

GESY940 wrote:According to "MY" schematics there are 2 switches..

Yes, diagram shows two pressure switches, one at dryer, and another one (high, most likely) after the dryer, then the compressor gets the juice, but it also informs 'big brother' (aka ECM) when it gets the juice.

GESY940 · Post by **GESY940** » 17 Mar 2015, 07:32

Thanks, ok I jumped the connector and "Nada"
So I toke my DVM and check for 12v and "Nada" again.
However I maybe making a bad ground connection with Volt Meter.
Do you know where the other switch should be?
Also let me point out ( you know this already ) according schematic there is only
one fuse and no relays, but here is something that maybe give you a hint?
Heater, fans everything work as you turn those knobs but the 2 little
push On / Off switches in the bottom never light-up ( Re-circulate & AC )

93Regina · Post by **93Regina** » 17 Mar 2015, 11:09

GESY940 wrote:check for 12v and "Nada" again.

I'll assume you have the ECC (electronic climate control), which I know nothing about.

High pressure switch may be located around condenser....follow high side after compressor, and presto, there it is.

2/10 in diagram is a "power unit ECC," and it has two sides, but its fed via common 12V bus.

>However I maybe making a bad ground connection with Volt Meter.

I don't want to hear that story...nail it.

GESY940 · Post by **GESY940** » 19 Mar 2015, 07:01

OK tried it again 12v were there at Low Pressure Switch.
I decided to do a quick test before spending much time and
bough a small can of R-134a, hook it up, turn car and ac switch on
then connect the clutch straight to the battery, the compressor
when on and even got some ( not much ) cold air inside the car.
So the line is open somewhere, will let you more soon, will work
on it today if not too cold Brrrrrrrr LOL

GESY940 · Post by **GESY940** » 27 Mar 2015, 08:29

I found this photo, the question is which one is the
High Pressure Switch ( there are 3 ) and how to
remove it & tested, any ideas?

93Regina · Post by **93Regina** » 27 Mar 2015, 12:13

GESY940 wrote:12v were there at Low Pressure Switch.

Great...now do an ohm test on that low pressure switch...does current flow thru it?

GESY940 · Post by **GESY940** » 27 Mar 2015, 12:43

Regina, there are 3 connectors, I don't know which one is the HP Sensor !
And how do I take it off, I'm afraid Freon may come out