ROG100

I need an early 78 to 79 AC relay please. They are NLA from all sources so a used one is my only option.
I would like more than one if I can find a couple. One for my car and the second one to have copied if possible.
Email me your price at roger@928sRus.com.
Thanks in advance.

jleidel

call Maddox. he has my 80'. i believe the ac relay in it is good.

borland

Wondering why you didn't make the call?

Try this Roger:

http://www.mailordercentral.com/928i...618%20105%2000

ROG100

Borland,
Mark was my first call - listing them and having them are two different animals. We emailed him again yesterday to double check though.
Roger

ROG100

Even though PET says used on 78 to 82 I am now pretty sure it was only used on 78 to 79 cars.
John your 80 was not fitted with one but I will ask Richard to make sure.
My 80 Euro does not have one fitted.

This early relay stops the AC compressor running while starting the car. Someone who will remain nameless sold mine to one of his customers. He was unaware it was unobtainium.

Hold On

Roger, I found a salvage yard in Phoenix that has a dozen 928`s out back. Many older models. Drop me a pm if you cant find them and I will add it to my next trip list in a few weeks. Kevin

Mike Simard

Where's it located? I may have one but would have to dig for it, seeing it's location will tell me, by an old pic, if it was there when my car was taken apart.

ROG100

Mike,
Bottom row sixth relay slot from the right. Double relays count as two.
Roger

blown 87

Is that the only purpose?
If so there are some work arounds for that.
Wont be stock, but it will get the job done.

Mike Simard

No luck. Mine had a jumper where the relay was supposed to be.

danglerb

A circuit diagram would be nice, maybe find a relay with similar or additional function.

I found this, but don't know what it means.

http://www.autowerkstatt-stein.de/Er...e/Neue_Seite_1
Relay 896 484 of Stribel 928 618 105 00 928 618 105 2000 911865 911 865

dr bob

Roger,

Are you looking at the engine/AC under-speed cutout relay, ID as J35 on the '78 wiring diagram, page VII? Purpose is to drop out the AC clutch at engine cranking speed, or more specifically until the engine has actually started. It will not be that hard to duplicate the function if you really need it. 555 Timer IC on a small PC board, a few discrete components, and a 53B relay module should be enough. (function would be virtually identical to the early fuel pump relay, with just a higher RPM trigger threshold, BTW) That linked input line on the schematic comes from the tach pulse signal that also feeds the fuel pump relay from the ignition module. The key here is the "if you really need it" question. It lessens the drag on the starter motor, keeps the aux air valve closed until the engine is actually running. If you don't have worries about the starter loading with the AC compressor, install a simple jumper between the 15 and 87 points for that relay in the CE panel.

If you want one that looks/feels/works like the original, you can open an early FP relay and change a couple components to move the RPM requirement a bit higher. IIRC, they have identical pin configurations already. The 31b contact strobes low on ignition pulses, if that helps.

ROG100

Dr Bob,
Your first paragraph went way over my head as I am electrically challenged.
I am quite happy to jump the relay as you suggest if it is as simple as that.
I did try jumping it just like the fuel pump relay and used the same slots. No worky for me.
I just want my AC to work in my 78 5 Speed.
Roger

dr bob

Simpified it for ya!


Seriously though, if you want to restore the original function, have Doc do a little surgery on a CIS fuel pump relay, so it takes more RPM's (>~~500) to get the relay coil to pull in. It should then be a plug-compatible piece. You could build the whole thing into a 53B case OK, but the slim-profile 31b contact isn't included in the standard 53B base.

mickster

Roger--supposedly it is in stock at Auto Atlanta for just shy of $100--Now I of course say that with the understanding that they often have stuff listed as in stock that just plain isn't and that their customer service is about the exact opposite of yours:

http://www.autoatlanta.org/detail.la..._number=103019

Hope they really have it!