| Author |
Message |
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32584
Location: Reading Pennsylvania
|
|
| Back to top |
|
 |
MarkWard
Samba Member
Joined: February 09, 2005
Posts: 17114
Location: Retired South Florida
|
 Posted: Fri Jul 16, 2021 11:50 am Post subject: Re: Rebuild...... 1990 Air Conditioning |
 |
|
Green O rings came on the scene with R134. I believe they were supposed to be compatible with the new refrigerant oil.
_________________
☮️ |
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32584
Location: Reading Pennsylvania
|
|
| Back to top |
|
|
dgbeatty
Samba Member
Joined: October 26, 2006
Posts: 702
Location: Sacramento
|
| Posted: Fri Jul 16, 2021 12:03 pm Post subject: Re: Rebuild...... 1990 Air Conditioning |
|
|
Re: orings. Green, viton, orings are required by regulation. Black orings, buna-n, are permeable to the r134a molecule.
_________________
Schau in das Buch |
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32584
Location: Reading Pennsylvania
|
|
| Back to top |
|
|
MarkWard
Samba Member
Joined: February 09, 2005
Posts: 17114
Location: Retired South Florida
|
| Posted: Fri Jul 16, 2021 12:07 pm Post subject: Re: Rebuild...... 1990 Air Conditioning |
|
|
I mentioned it only because the expansion valve is the most difficult to access when the system is assembled. You are there and I am not. 
_________________
☮️ |
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32584
Location: Reading Pennsylvania
|
|
| Back to top |
|
|
Selsk
Samba Member
Joined: January 17, 2015
Posts: 135
Location: LA, CA
|
| Posted: Fri Jul 16, 2021 2:49 pm Post subject: Re: Rebuild...... 1990 Air Conditioning |
|
|
| djkeev wrote: |
That is an insulated cover for the temperature sensing coil.
Dave |
Do you also have the little foam cozy that goes around the whole valve?
I'm going to have to get back in there and maybe I'll clean the coil this time around. I wish I had a really tall jack that I could use to hold the housing in place. It was a real pain in the ass to get it back into place with two guys...and I managed to snap off some material around the bolts. Luckily Gowesty has a bracket kit they sell to support the housing. |
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32584
Location: Reading Pennsylvania
|
| Posted: Fri Jul 16, 2021 3:55 pm Post subject: Re: Rebuild...... 1990 Air Conditioning |
|
|
Well........ off to the Van we go!
Hazy
Hot
Humid
I used a combination of 2x4’s plywood, shims and saw horses to get the Evaporator up near the ceiling.
Once up there I was able to assemble the two hoses to the expansion valve
I inserted the temperature probe into the coil and taped the wire to the Evaporator housing.
I used the cork / Tar insulating tape and wrapped the exposed pipes.
I then put on the foam expansion valve insulating cover and taped it closed.
Then it was a simple matter of "walking" the assembly up to the ceiling using scraps of lumber.....
Once up and tightly wedged in place the real fun began!
Working in zero space, hot sweaty and tired I found the 6mm threaded holes to mount the front of the assembly up.
What a bear of a job by myself!
The rear is held up with some proprietary nut that is long gone on my unit.
I simply used self tapping hex head screws.
It is up, I'm beyond exhausted and it is late!
My older Brother in Crescent City was texting, wondering why I'm ignoring him today..... 
The skies are dark, thunder rumbles......
Tomorrow is another day.
I still need to puzzle out burned wires and make repairs.
I need to hook up hoses to the compressor and
I need to install the receiver/dryer.
I'll do the hoses first thing and let the system evacuate while I puzzle the electrics.
I have no idea how long the condensate hoses should be?
And does it really matter?
Dave
_________________
Stop Dead Photo Links how to post photos
Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473
Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537
Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert
Last edited by djkeev on Fri Jul 16, 2021 4:18 pm; edited 1 time in total |
|
| Back to top |
|
|
dgbeatty
Samba Member
Joined: October 26, 2006
Posts: 702
Location: Sacramento
|
| Posted: Fri Jul 16, 2021 4:11 pm Post subject: Re: Rebuild...... 1990 Air Conditioning |
|
|
Dave I extend the condensate tubing thru the lower horizontal floor plate. The area below the floor plate is a low pressure area and helps to suck the water out. The downside is that it is a very dusty area. The TÜV requires a one way valve, the duck bill, to eliminate any possibility of CO being pulled inside (it isn't a problem as the pressure in the AC housing is MUCH MUCH higher). Cut the end of the tube diagnoly and leave the end open. If you simply must install the duckbill valve remember to clean it annually.
Just drill a hole and use an appropriately sized grommet. I prefer the hard plastic grommets for this sort of thing.
BTW what material did you use in front of the evaporator to catch the moisture?
_________________
Schau in das Buch |
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32584
Location: Reading Pennsylvania
|
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32584
Location: Reading Pennsylvania
|
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32584
Location: Reading Pennsylvania
|
| Posted: Sat Jul 17, 2021 7:43 am Post subject: Re: Rebuild...... 1990 Air Conditioning |
|
|
Well........
It was 10:00 AM Eastern time when I turned on the Vacuum pump!
That's where I had wanted to be by dinner last night.
Oh Well....... I'm making progress anyway!
It quickly pulled the gauge down but we've got hours yet ti pump down.....
I installed the Receiver/Drier in the "factory" location in the Left Rear Wheel cavity......
I have my High Pressure Port on the 90° Attaching the 06 size hose from the Condenser.
Because of this I have the gauges on top of the tire for my hoses aren't long enough to reach around!
The low Pressure Port is at the Compressor .....
The high pressure connection has a port on it as well but it ended up buried by the coil.
I could use it but I installed the one at the receiver/drier which has easy access.
The screwdriver tip is touching the compressor High Pressure Port......
The correct amount of oil is in the lines and components.
Taking a break and cooling off. I will then go attack the wiring. It shouldn't be too bad, I've got a solid grip on what needs to happen........ at least it makes sense in my head!
Time will tell.
Dave
_________________
Stop Dead Photo Links how to post photos
Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473
Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537
Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert |
|
| Back to top |
|
|
dobryan
Samba Member
Joined: March 24, 2006
Posts: 16501
Location: Brookeville, MD
|
|
| Back to top |
|
|
DuncanS
Samba Member
Joined: October 17, 2013
Posts: 4583
Location: New Hampshire
|
| Posted: Sat Jul 17, 2021 8:02 am Post subject: Re: Rebuild...... 1990 Air Conditioning |
|
|
The thin plastic housing after 30 years isn't really able to hold up the entire evaporator assembly by just the three bolts on either side in the front and the screws/plastic nutted coarse welded studs in the rear. I took out both supporting hose/wire covers as I wanted the cargo width. Got away with it for about 4 years and then hit a pot hole. The entire unit came crashing down supported only by the hoses.
Didn't want to break the hose connections so lived with it like this for a year. Sure loved the unrestricted rearview mirror visibility and that when I decided to modify things to raise it up.
This is my current visibility and will go up another 3/4" The evaporator coil is in place ontop of a temp ply platform so the exterior lump doesn't need to be very high.
You'll be OK on smooth roads providing the housing shows no cracks around the bolt holes. There is plenty of thread, so another option, if you want to buy time while sorting out the wiring issues, is to cut a pice of 3/8" ply and put it under the housing and bolt up through so you have in effect a larger support area than just the three hole metal plate. |
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32584
Location: Reading Pennsylvania
|
| Posted: Sat Jul 17, 2021 10:35 am Post subject: Re: Rebuild...... 1990 Air Conditioning |
|
|
So while the Vacuum pump does its thing I've been making wire repairs.
I am aware that there are inherent weak points in the A/C loom design and I originally intended to fix them now.
But I don't know if this system even works.
I thought it may be prudent to just repair it as designed and once proven functional make modifications to the wiring.
My thinking may be flawed, but........
I crimped on a new power feed terminal, it didn't have a terminal or a screw to hold the terminal to the fuse block.
I rooted around and found a screw and washer that will work but I'll source a proper brass one later.
I cleaned all the grounds and installed them tight.
I dug out my new 40amp fan relay.
I had a strange blue wire which was added by someone at some point. I cut out the entire boogered connector and installed a new one.
I crimped a new terminal on the feed wire at the alternator, that one was showing its age!
The new Sanden of course didn't have VW compatible connections so I cut off the one from the old compressor and spliced it in,
The only repair left is repairing the burned three connector to the temp control box.
My worry here is two black wires.
Looking at the wiring diagram they simply complete a circuit at the Switch. I don't think it matters who pairs with who.
Anyway
I've got a 50% chance of success!
And a 50% chance of failure.
Glass half full or half empty?
I picked up a replacement plug that I'll wire in,
I shut off the vacuum pump for lunch, I'll see if there is any loss.
If there is no loss of vacuum I'll screw on the trinary switch and see if my modification is tight or not.
Dave
_________________
Stop Dead Photo Links how to post photos
Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473
Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537
Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert |
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32584
Location: Reading Pennsylvania
|
| Posted: Sat Jul 17, 2021 11:42 am Post subject: Re: Rebuild...... 1990 Air Conditioning |
|
|
Ok, temperature control is wired in with a plug.
I simply guessed on the blacks, actually I followed what was there.
Maybe the first person in there had a hint in the ashes of what wire went with what wire.
If not?
Easy enough to change.
I screwed on the trinary switch, in an hour there wasn't any vacuum drop.
So I plugged it in!
I then figured...... WHY NOT?
I hooked up the the D pillar power feed to the alternator stud.
No sparks, no clicks, no smoke.
I went to the front and climbed in.
I made sure the A/C and fans were off and turned the key on. (Didn't start it)
Silence....... silence is good.
I reached over and turned the snow flake knob.
The Van came to life!
The front radiator cooling came on as it should.
So far...... so good.
The blower fan was on 1 which I would thing is low but it was blowing air on the back of my head.
Hmmm.......
Switched it to 2 ....... the speed increased!
Ok, seems odd that 1 & 2 are moving so much air but ok.......
Switched it to 3....... air flow died off! Hmmmmmm
Switched it to 4 ...... no different than 3
I left it on 4 and went to the rear (my hearing sucks) and put my hand in front, air is moving but slowly.
Tried it on 3 no noticeable difference.
I'm inside now looking at wiring diagrams.
I take comfort in the fact that I had all four speeds on the bench.
There is something in the wiring........
I just need to grasp how it works and then figure out the fix.
I turned the vacuum pump back on.
I'll vacuum it until dark and let it sit over night. See what the morning brings.
Dave
_________________
Stop Dead Photo Links how to post photos
Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473
Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537
Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert |
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32584
Location: Reading Pennsylvania
|
|
| Back to top |
|
|
DuncanS
Samba Member
Joined: October 17, 2013
Posts: 4583
Location: New Hampshire
|
| Posted: Sat Jul 17, 2021 2:08 pm Post subject: Re: Rebuild...... 1990 Air Conditioning |
|
|
Dave
Fan speed 3 is controlled by a multi switching switching relay J32 shown on Bentley 97.144. The separate coil feed is shown on 97.143 as "a". I'm guessing that this relay is kaput and may have corroded contacts creating resistance, thereby slowing down the fan speed. Speed 4 is controlled by the relay shown on 97.143 as J157. Both of these relay contacts carry high loads and may have corroded and are creating a higher than normal amp draws and could be the cause of the fire. I would bypass both with test jumpers and see if you get the right speeds. If so, this should confirm the relays have failed and would need replacing. If you want, it would be possible to abandon the fan portion of the multi switching relay and use a standard 50 amp SPST relay as a substitute. The internal wiring could easily be added externally and achieve the same result. However, if there were excessive temps inside it, then better to get a new one or create you own triple. It also might be a connector problem as well. Check to see if any of them are discolored or appear to have suffered high heat.
I'm convinced that the fan speed issue is what caused the fire.
I know you will get this solved and soon have the AC working well.
Duncan |
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32584
Location: Reading Pennsylvania
|
|
| Back to top |
|
|
|
