TIPEC

The TIPEC Forum
It is currently Tue Nov 13, 2018 8:17 am
Asset Trust


All times are UTC [ DST ]




Post new topic Reply to topic  [ 27 posts ]  Go to page Previous  1, 2
Author Message
 Post subject: Re: S2 Heater problems
PostPosted: Wed Jan 24, 2018 7:04 pm 
Offline
User avatar

Joined: Sun Mar 11, 2012 11:03 am
Posts: 448
Location: Bolton U.K.
TIPEC membership: 6602
Yes that's the chip, the guys in the States claim to be able to repair it even upgrade it but the price is rather unattractive. Hardly cheap as chips.

_________________
Porsche 944 S2 Coupe Guards Red
Porsche 993 Coupe Guards Red
Ducati 998 FE Red oc


Top
 Profile  
Reply with quote  
 Post subject: Re: S2 Heater problems
PostPosted: Thu Jan 25, 2018 9:20 am 
Offline

Joined: Sat Dec 27, 2014 8:22 pm
Posts: 159
TIPEC membership: 0
I have already replaced that chip(IC4)LM2902N, actually the equivalent as now very hard to find the LM2902N; as I had the exact same issue as the Rennlist member mentioned. It wasn't expensive & took the CCU to a tech due to it having multiple legs, so was worth the try. It did not solve mine!


Top
 Profile  
Reply with quote  
 Post subject: Re: S2 Heater problems
PostPosted: Thu Jan 25, 2018 11:45 am 
Offline

Joined: Tue Nov 19, 2013 11:48 am
Posts: 1665
Location: West Essex
TIPEC membership: 0
karozza wrote:
I have already replaced that chip(IC4)LM2902N, actually the equivalent as now very hard to find the LM2902N; as I had the exact same issue as the Rennlist member mentioned. It wasn't expensive & took the CCU to a tech due to it having multiple legs, so was worth the try. It did not solve mine!



Mouser Electronics have 3900 in stock

_________________
Cobalt Blue 968 Coupe 1992


Top
 Profile  
Reply with quote  
 Post subject: Re: S2 Heater problems
PostPosted: Thu Jan 25, 2018 1:24 pm 
Offline

Joined: Sat Dec 27, 2014 8:22 pm
Posts: 159
TIPEC membership: 0
Waylander wrote:
karozza wrote:
I have already replaced that chip(IC4)LM2902N, actually the equivalent as now very hard to find the LM2902N; as I had the exact same issue as the Rennlist member mentioned. It wasn't expensive & took the CCU to a tech due to it having multiple legs, so was worth the try. It did not solve mine!



Mouser Electronics have 3900 in stock


My mistake!

Originally, Shibstead, the Thread Starter mentioned the IC4 LM2902DP was needed; IIRC this was difficult to find & the LM2902N is what he actually used & later edited. As you correctly mention is quite easy to find.


Top
 Profile  
Reply with quote  
 Post subject: Re: S2 Heater problems
PostPosted: Sun Jan 28, 2018 9:37 pm 
Offline
User avatar

Joined: Sun Mar 11, 2012 11:03 am
Posts: 448
Location: Bolton U.K.
TIPEC membership: 6602
I feel really sick just blown a fortune on a new ccu and heater still does not work. It'll probably be a bad contact somewhere. So dig out the wiring diagram again and check all connections, earth points and continuity of wiring. My projector mod is working though, well o/s only on dip and it's a great improvement superb foreground with very sharp cut off, I forgot to order the correct harness.

_________________
Porsche 944 S2 Coupe Guards Red
Porsche 993 Coupe Guards Red
Ducati 998 FE Red oc


Top
 Profile  
Reply with quote  
 Post subject: Re: S2 Heater problems
PostPosted: Mon Jan 29, 2018 3:06 pm 
Offline

Joined: Sat Dec 27, 2014 8:22 pm
Posts: 159
TIPEC membership: 0
Endoman wrote:
I feel really sick just blown a fortune on a new ccu and heater still does not work. It'll probably be a bad contact somewhere. So dig out the wiring diagram again and check all connections, earth points and continuity of wiring. My projector mod is working though, well o/s only on dip and it's a great improvement superb foreground with very sharp cut off, I forgot to order the correct harness.


I really feel for you mate as it's very tedious when these things happen.

At least you're making progress on the Projector Mod; did you buy them from somewhere, a link perhaps?


Top
 Profile  
Reply with quote  
 Post subject: Re: S2 Heater problems
PostPosted: Mon Jan 29, 2018 9:15 pm 
Offline
User avatar

Joined: Sun Mar 11, 2012 11:03 am
Posts: 448
Location: Bolton U.K.
TIPEC membership: 6602
All working, went back to the beginning and checked the sensors again. Internal temp sensor reading a tenth of what it should be. I'd checked and rechecked them several times. Already replaced the mixer one. Did I read it wrong or was it trying to fool me or have I got the first stages of dementia. I feel such a twerp, spent a fortune when it was a simple cheap part.
The projectors are Morimoto H1 7s from emtuning.co.uk/ with reference to this post on Rennlist:-https://rennlist.com/forums/924-931-944-951-968-forum/802951-another-944-xenon-projector-mod.html I used Wipac old type Mini headlamps as a base and the bowls from same as spacers. I'll write it up with some photos.

_________________
Porsche 944 S2 Coupe Guards Red
Porsche 993 Coupe Guards Red
Ducati 998 FE Red oc


Top
 Profile  
Reply with quote  
 Post subject: Re: S2 Heater problems
PostPosted: Tue Jan 30, 2018 9:29 am 
Offline

Joined: Sat Dec 27, 2014 8:22 pm
Posts: 159
TIPEC membership: 0
Endoman wrote:
All working, went back to the beginning and checked the sensors again. Internal temp sensor reading a tenth of what it should be. I'd checked and rechecked them several times. Already replaced the mixer one. Did I read it wrong or was it trying to fool me or have I got the first stages of dementia. I feel such a twerp, spent a fortune when it was a simple cheap part.
The projectors are Morimoto H1 7s from emtuning.co.uk/ with reference to this post on Rennlist:-https://rennlist.com/forums/924-931-944-951-968-forum/802951-another-944-xenon-projector-mod.html I used Wipac old type Mini headlamps as a base and the bowls from same as spacers. I'll write it up with some photos.


Great! Please do a write up with some pics.

So, you just replaced internal temp sensor? May I ask how you checked the sensor reading as I would like to do this thoroughly? Also, where did you buy it on line as I think all three temp sensors are the same & if not expensive, might just replace what ever's hidden behind the dash!? I have the dash completely removed so will avoid going back there again.


Top
 Profile  
Reply with quote  
 Post subject: Re: S2 Heater problems
PostPosted: Tue Jan 30, 2018 9:49 am 
Offline

Joined: Mon Nov 23, 2015 7:31 pm
Posts: 60
Location: Cheshire
TIPEC membership: 8044
Congratulations on getting it fixed, which is the main thing.

At least you now have a spare control unit which I'm sure you will be able to sell on in the near future. Lots of people are put off buying things from the States because of the duty hassles. You also now know your way around the 944 heating system so future fixes will be child's play.

Enjoy the heat in this cold weather.

Matt

_________________
1986 944 Lux


Top
 Profile  
Reply with quote  
 Post subject: Re: S2 Heater problems
PostPosted: Tue Jan 30, 2018 11:18 am 
Offline

Joined: Tue Nov 19, 2013 11:48 am
Posts: 1665
Location: West Essex
TIPEC membership: 0
I do believe they are all the same thermistor, ND03N00103J, RS part number 967-4465,

_________________
Cobalt Blue 968 Coupe 1992


Top
 Profile  
Reply with quote  
 Post subject: Re: S2 Heater problems
PostPosted: Wed Jan 31, 2018 1:46 am 
Offline
User avatar

Joined: Sun Mar 11, 2012 11:03 am
Posts: 448
Location: Bolton U.K.
TIPEC membership: 6602
Yes they are all the same, the 2 internal ones are a simple thermister on mine, a bit tricky to get at but doable the exernal one was an enclosed type so a bit more difficult to do, if possible. It's the same as rear intake air temp sensor in a 993. I found the mixer one most awkward to get at, I dismantled the plug to feed it's wires through the grommet hole and did the soldering on the work bench but getting the grommet back in was a real pain, old hard rubber. should have used a new grommet. Did a run up to Fleetwood today (no, I was not feeling suicidal) the traffic was dire but at least I had a working heater.
There is a table in the workshop maunual which gives the resistance readings at various temperatures, mine were 17.85kohms @ about 10 c. not sure what the tolerance is. The faulty one varied a lot from same as rest to 0.2kohms which is why I missed it on first test and proceeded up a blind alley.
Found it.
From plug A:-
Outer sensor terminal 9 to ground;-
@ 0 C 34 kohm +/- 10%
@ 10C 20kohm
@ 25C 10kohm
Interior sensor (the one with the fan)
terminal 2 to ground
Mixer sensor (behind center vent)
terminal 1 to ground.
The thermisters are dirt cheap but complete sensors are either nla or expensive.
The heater on my old MGA was never a problem, levers and cables.

_________________
Porsche 944 S2 Coupe Guards Red
Porsche 993 Coupe Guards Red
Ducati 998 FE Red oc


Top
 Profile  
Reply with quote  
 Post subject: Re: S2 Heater problems
PostPosted: Thu Sep 27, 2018 4:39 pm 
Offline

Joined: Sat Dec 27, 2014 8:22 pm
Posts: 159
TIPEC membership: 0
Endoman wrote:
Yes they are all the same, the 2 internal ones are a simple thermister on mine, a bit tricky to get at but doable the exernal one was an enclosed type so a bit more difficult to do, if possible. It's the same as rear intake air temp sensor in a 993. I found the mixer one most awkward to get at, I dismantled the plug to feed it's wires through the grommet hole and did the soldering on the work bench but getting the grommet back in was a real pain, old hard rubber. should have used a new grommet. Did a run up to Fleetwood today (no, I was not feeling suicidal) the traffic was dire but at least I had a working heater.
There is a table in the workshop maunual which gives the resistance readings at various temperatures, mine were 17.85kohms @ about 10 c. not sure what the tolerance is. The faulty one varied a lot from same as rest to 0.2kohms which is why I missed it on first test and proceeded up a blind alley.
Found it.
From plug A:-
Outer sensor terminal 9 to ground;-
@ 0 C 34 kohm +/- 10%
@ 10C 20kohm
@ 25C 10kohm
Interior sensor (the one with the fan)
terminal 2 to ground
Mixer sensor (behind center vent)
terminal 1 to ground.
The thermisters are dirt cheap but complete sensors are either nla or expensive.
The heater on my old MGA was never a problem, levers and cables.


I have now tested everything, including temp thermisters again, still no success. HCV still won't shut off hot water supply! 2 theremisters read basically the same & the mixed chamber sensor reads around 1Kohm less, so not as accurate but still functioning.

​​​​​​​No idea what else to do!? :?


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 27 posts ]  Go to page Previous  1, 2

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 22 guests


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:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group