It is currently Sun Nov 19, 2017 10:55 pm




Post new topic Reply to topic  [ 6 posts ] 
 ac gremlins 
Author Message
Speed Limit Obeyer
User avatar

Joined: Thu Nov 25, 2010 12:19 pm
Posts: 81
Location: Melbourne, Australia
Post ac gremlins
Hey everyone so being summer here i decided to finally get my ac fixed to deal with the scorching tempretures and in the process it seems i've run across a couple of the 928 cliches lol.
firstly the climate control would always blow scorching hot air, so quick search on the net identified this to be the hot water valve under the air intake, pulled it, cleaned it still no go so i removed the vacuum actuator and zip-tied it shut (i'm ordering a new valve currently) problem solved.

ac still wasn't working properly so went and got it regassed. the mech told me that it wouldn't turn on, he regassed it anyway then hotwired it and apparently it worked fine.

so i took it home to sort out the gremlins by myself. the wire was getting power but as soon as there was a load placed on it there would be no voltage. after tearing my hair out and pulling half the car apart, i decided to look up the fault on the net, apparently it's quite common and can be traced to the little blue relay on the pcb inside the hvac.

pulling the hvac apart i tested the relay and it was indeed the scource of the problem. the standard solution is to replace the relay with a larger more durable one however i had a different idea, i popped the top of it with a tiny flat blade screwdriver then ran some 600 grit sandpaper over the contacts, da da ac works perfectly. however due to the obvious need for a larger relay to consistantly handle the large currant drawn by the compressor clutch i will install a new automotive relay in the fuse box.

_________________
1986 Porsche 928 "ROW" 5 Litre Auto Metallic Maroon - Maroon/Brown Leather Interrior
(and whilst it's not a Porsche)
1948 Morris MS-6, 2.2 strait 6, 4 on the tree manual, green exterior, red leather interior


Wed Jan 11, 2012 3:58 pm
Profile
Webmaster
User avatar

Joined: Mon Jan 07, 2008 8:43 pm
Posts: 2078
Location: Sunny San Diego
Post Re: ac gremlins
Yup, you found the famous little relay in the hvac. I was going to change mine but in the S, it was totally different so I did the same as you, opened it and cleaned and also the board wherever there was contact with the sliders. Works like a charm now.

_________________
1981 Porsche 928 "Euro" 4.5 Litre Auto Gunsmoke Metallic Flat - Black Interrior
1983 Porsche 928S "US" 4.7 Litre Auto Light Bronze (Copper) Metallic - Brown Interior


Wed Jan 11, 2012 5:53 pm
Profile
Speed Limit Obeyer
User avatar

Joined: Thu Nov 25, 2010 12:19 pm
Posts: 81
Location: Melbourne, Australia
Post Re: ac gremlins
ok so disaster :/ firstly the relay worked for about 5 minutes then stopped again, i'm assuming it's just too high a load, so i'm going to have to put that automotive relay in now.

unfortunatly during my searches i came across a multipin connector which was behind the fuse panel and unplugged, thinking this might have been the problem i plugged it back in...

it was the stock alarm system :o so the next time i opened the car the alarms going off like crazy and the car wont start even if i unplug the connector again, now i have the "s" key however to turn off the alarm you have to unlock the car from the passenger side and on my car the passenger side lock doesn't turn from the outside, so now i'm on an epic mission to try and fix that lock as well as re-repair the hvac relay.

thanks for listening to the whinge lol

_________________
1986 Porsche 928 "ROW" 5 Litre Auto Metallic Maroon - Maroon/Brown Leather Interrior
(and whilst it's not a Porsche)
1948 Morris MS-6, 2.2 strait 6, 4 on the tree manual, green exterior, red leather interior


Thu Jan 12, 2012 2:30 pm
Profile
Speed Limit Obeyer
User avatar

Joined: Thu Nov 25, 2010 12:19 pm
Posts: 81
Location: Melbourne, Australia
Post Re: ac gremlins
alright!!! :D relay replaced! i used a DPDT 10 amp 12 volt relay that i just happened to have sitting around. The ac works perfectly!!!! this is amazing
the alarm well lets just say i shorted the two wires that turn it off and left it at that i'll probably try to sort it out properly when i do some work on the trim in the doors which i'm planning at some point.

regardless the car's running nicely... enough... for now.
and i get beautiful cold air. it's 31tomorrow (i think that's about 85 or 90 for you F boys???) can't wait to test it.

_________________
1986 Porsche 928 "ROW" 5 Litre Auto Metallic Maroon - Maroon/Brown Leather Interrior
(and whilst it's not a Porsche)
1948 Morris MS-6, 2.2 strait 6, 4 on the tree manual, green exterior, red leather interior


Sun Jan 15, 2012 4:42 am
Profile
Webmaster
User avatar

Joined: Mon Jan 07, 2008 8:43 pm
Posts: 2078
Location: Sunny San Diego
Post Re: ac gremlins
Wow, 85 degrees in January. Great fix and post.

_________________
1981 Porsche 928 "Euro" 4.5 Litre Auto Gunsmoke Metallic Flat - Black Interrior
1983 Porsche 928S "US" 4.7 Litre Auto Light Bronze (Copper) Metallic - Brown Interior


Sun Jan 15, 2012 10:23 am
Profile
Speed Limit Obeyer
User avatar

Joined: Thu Nov 25, 2010 12:19 pm
Posts: 81
Location: Melbourne, Australia
Post Re: ac gremlins
thanks, sorry for the lack of pictures but i was too busy keeping myself from grabbing the sledgehammer :P

yeah it's the middle of summer over here, 31 or 85 isn't actually that hot, we'll be pushing 40 or 45 (100ish) before it's over, it's the season of thongs (i think you call them flip flops?) shorts, singlets bbqs icy cold beer, makes for a great way to bring in christmas and the new year. although in melbourne we had a white christmas this year, well sort of, we had a random hail storm with hail stones the size of golfballs completly covering the front lawn, it was pretty intense!

_________________
1986 Porsche 928 "ROW" 5 Litre Auto Metallic Maroon - Maroon/Brown Leather Interrior
(and whilst it's not a Porsche)
1948 Morris MS-6, 2.2 strait 6, 4 on the tree manual, green exterior, red leather interior


Sun Jan 15, 2012 3:13 pm
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6 posts ] 


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB © phpBB Group.
Designed by Vjacheslav Trushkin for Free Forums/DivisionCore.