A/C wizards! Need help with Denso system, receiver drier switches

[jd_e30]

ha! anything you need... i think I have a single switch but not sure. mine was converted some time ago, but now I'm stuck on replacing the bosch r12 compressor, whichi sl isted as incompatible. Hoping you could shed some light on that.

[boy412]

Maybe one of the A/C gurus will chime in here. I'm pretty much a neophyte when it comes to the climate control systems on these cars. What is it about your Bosch that isn't compatible? I learned a little about some of the various compressor options. Denso ones are a little different but Bosch & Seiko are (allegedly) interchangeable.

[jd_e30]

A/C wizards! Need help with Denso system

The ac has not been blowing very cold so I did some research after verifying refrigerant pressure...

That ac compressor installed is part number 64 52 1 377 946 per attached screenshot.

If you look at this bmw document, http://www.bmwe34.net/E34main/Upgrad...a_retrofit.pdf it is listed as a non-compatible compressor for r134a.

I need compressor part number 64 52 8 363 550 but reluctant to spend $450 on one.

Another good resource: http://www.koalamotorsport.com/tech/...nditioning.asp

[jeffnhiscars]

Again...the only thing compatible about them is the seals. Its still designed for r12 so it makes zero sense to spend $450 when for less than half that (plus the mounting brackets)you can get a NIB modern compressor intended for r134a

[uturn]

Re: the denso compressor, I've only had bad luck with rebuilt units. Ditched it and went to seiko seiki units, rebuilt them proper and all three of my e30's blow cold. Tried to rebuild my Bosch unit but couldn't get the pulley off.

[cabriodster87]

Oh you mean THIS one? I had found that a year ago when I first got the car. Lots of good info for sure! Although I don't recall seeing anything in there about the two switch vs one switch thing. Admittedly I did not read all 7 pages though.

https://docs.google.com/file/d/0B4vP9afE06OqNWI3M2FkMTQtZDczMS00NWVjLWFhNmYtNDc4NGIwZTdkNjdh/edit?authkey=CNO6w-8O

Here is the link from the conversion thread, starting on about page #3 you will see very detailed instructions and illustrations to properly convert the drier switch wiring. GL

[boy412]

I wanted to update this thread regarding the O-rings. The ones I ordered were correct and fit properly. I'm glad I pulled those two "connectors" off the compressor because two of the four O-rings (the two on the right in the picture below) were SHOT.



The O-ring is indeed Four Seasons p/n 24613. I got them at Rock Auto for 30¢ each plus shipping.



The bolts are standard M8 x 1.25 x 20mm socket cap screws. I got new stainless ones at Allen's Fasteners for 34¢ each.

[cabriodster87]

No problem, stay cool!

EDIT: shouldn't the 134 "O" ring be green or tan? I've seen blue ones also, color blind anyway. Anything except black in 134 systems.

like this:

[boy412]

https://docs.google.com/document/d/1...LOZEG8prg/edit

Here is the link from the conversion thread, starting on about page #7 you will see very detailed instructions and illustrations to properly convert the drier switch wiring. GL

Thats very helpful...thanks! I'm not sure how I didn't see that link in the conversion thread.

One thing that is still not clear is the repair set they mention (1 378 400). The part I have is just the connector with no wiring in it. I assume then I'll need something like this to actually go into the connector, that can then be spliced into the switch harness?

[boy412]

No problem, stay cool!

EDIT: shouldn't the 134 "O" ring be green or tan? I've seen blue ones also, color blind anyway. Anything except black in 134 systems.

like this:

The replacements I bought are green (probably Viton). The black ones in my photo were the old ones...and probably original to the compressor I got.

[cabriodster87]

You should have this one

[boy412]

Yes...that is the switch I have. AND I have the female connector it plugs into as well...but no wires that actually go inside that connector. Its just a shell of a connector.



You can see this connector is just a shell...no female plug inside!

[brahbarian]

Sorry to back track, but for the early model dryer switches, which one is which. I have a green one that's toward the engine and a bigger black one towards the head light.
Whats the difference?
I'm trying to get mine to work. I switch out the. Green one thinking it was the low pressure switch. If I jumper that green one to a power source It kicks on the compressor.

Sent from my SM-G900P using Tapatalk

[jeffnhiscars]

Let me correct myself after having reviewed my build thread....I replaced my HP switch. It was the LP I could not get. Fortunately its not hard to test a 25lb switch so I reused it with confidence.

[boy412]

Sorry to back track, but for the early model dryer switches, which one is which. I have a green one that's toward the engine and a bigger black one towards the head light.
Whats the difference?
I'm trying to get mine to work. I switch out the. Green one thinking it was the low pressure switch. If I jumper that green one to a power source It kicks on the compressor.

Sent from my SM-G900P using Tapatalk

Green one is high pressure. The stubby black one is low pressure.