wds928

Nice work Bill. Agreed, shop time to diagnose would have been very expensive. How's the refrigerant level and how cold does it get at the vents?

Mine took 1.5 pounds a couple of weeks ago. I recall it needed R134 also the prior year. I understand the R134 refrigerant molecules are smaller than R12 and can leak out more. Anyway, my A/C is super cold, even in high humidity.

Bill Ball

This car seems to be leak-free. It's R-134a and I checked the pressures and scanned the likely leak spots with a sniffer before I started to work on it. I haven't measured temps at the vent, but they are cold. It was about 90F today and the vents were cold. You know my 89 with R-12 blows in the 20s.

A 94 GTS is equipped with barrier hoses designed for R-134a - the R-134 shouldn't leak through them. 1.5 lbs in a year is not a lot, but there probably is a small leak that sniffer could find.

No one explained why your relay wiring worked, when you wired a RS 275-218 to a Matsu****a relay equipped board as it if were a Gruner relay board. Eh, be happy.

Alan

Bill - for someone who claims to be virtually incapable with electrical things - you seem to be doing pretty OK to me...

Alan

Bill Ball

Alan: After reading your primers and posts and staring at the wiring diagrams, some of it may actually be sinking in. Thanks again for being such a great resource.

wds928

This is the kind of resource that makes Rennlist such a great value and a must have for any 928 owner.

Electronics are barely understandable by me, so I have no idea why mine worked and certainly had no idea there were differences in the Gruner and Mats relays. Sometimes its better to be lucky than good.

Anyway, glad your A/C project turned out so well. Stay cool.

docmirror

Glad you have cold air Bill. You'll appreciate that every summer now.

docmirror

I've just done another Matsu****a type and realized my instructions could be misconstrued depending on how the head was oriented on the table. so, I revised post 11 to more accurately define the location of the connector holes on the head.

To recap. The wires furthest from the edge connector go to the coil pick, 7 & 8. The center wires go to the relay wiper, 5 & 6, and the wires closest to the edge connector go to N.O., 3 & 4. This is much different than the previous Gruner style, so be careful.

tndavies

Good Evening,
I encountered a different relay when I opened my 1986 control panel. I bought the car recently and the controller may have been replaced once before - not sure. The relay has a similar part number as the Masu****a but it's an "NAIS". Any ideas where this controller relay came from ? If so, what relay mapping do I use - the Masu****a or Gruner ?

tom davies

Bill Ball

Here's a picture Tom sent me of the relay. Based on the model year, the pinout should match the Gruner, but I can't say for sure.

Bill Ball

Tom: Look at the underside of the circuit board. Does this relay have 8 pins coming through or just 6, like the Matsu****a (see previous posts)?

Bill Ball

Tom: Note that your relay has the same PN as the Matsu****a. That pretty much nails that you should use the later pinout, not the Gruner.