IceShark

Both of you are beyond me on electronics so perhaps you could give me some ideas on my recent problems.

First my turn signal flasher relay (original on an 88 951S) went. Removed it and for kicks took it apart while watching TV. A small metal spike had been welded up preventing the contacts on the electro-mechanical switch from closing face to face. Shaved that off and the thing worked again ..... for a few days. Then it just failed flat out (it was an electronic not thermal timer). Put in an aftermarket electronic relay last week and so far so good.

Shortly after home flasher repair, I go to open my sunroof and the sunroof and whole instrument cluster goes dead. Blown fuse. Replace with another 7.5 amp fuse and blow that again after hitting the sunroof switch. Replace with 15 amp fuse, it doesn't blow, but the sunroof will not work properly. After tracing around I was nearly certain the relay on the fuse board was at fault and not switching polarity.

The do-it-myself flasher repair was still working and I was feeling proud, was dismayed to see a new sunroof relay cost over $100, so I opened up the relay. Discovered a *melted* copper trace line on one printed circuit board. The green dielectric/anti-solder rosin was also melted quite a ways. Soldered the trace back together and sunroof works fine, even with proper 7.5 amp fuse back in.

I originally attributed the sunroof failure to the mechanicals being stiff from not being used for 5 months which overloaded the motor, blew the fuses, and somehow the relay wasn't protected enough by fuses and it melted the copper trace. But the arc welded spike on the flasher contacts has me wondering if something common is at work or if the two items are seperate.

I did beef up my electrical system and there is a full 13.8+ volts available under heavy amp load at all the places that count such as fuse board and lights.

- just age showing?
- sunroof relay didn't have 15 amps going through it so wonder why it melted? Wimpy relay? I did have a new 30 amp rated foglight relay which was fused at 20 amps weld itself together when I accidentialy shorted the bulb terminals. These fuses must not blow quick enough?
- if this is a design cycle life thing, I'm going to spend a fortune on relays as some are quite expensive.

Thanks for any comments.


P.S. BTW, why did those crazy Germans make resetting the airbag warning light such a long on/off grounding deal? And why does the warning light come on everytime the fuse blows or is pulled out when power is on? I fear I unfortunately have the reset sequence memorized for life.

Adrian

Just a case of age and lack of use. The relays in the 944 series (and 911) were often VW/Audi units. Not that this should be a problem but maybe they were just not rated high enough. Good clue here. Do not purchase the Porsche units but the VW ones to save money. A fog light relay for my 911 from Porsche was 117DEM ($US50,00). From VW was 17DEM and Audi 39DEM. Part number from the OEM was the same, cover was the same colour just the Porsche one had a Porsche part number as well.
Same applies to the electric water pumps for the windshield and others things. Purchase the VW/Audi version. Much cheaper, same pump.
Relays fail. I have had three go on my 944 and two on 911. (so do the water pumps).
Now I know you are in the USA and you guys "Love" these sunroofs, I hate them, too heavy and more moving parts to fix however look around for collegues without sunroofs. Porsche often installed the relays. Now if your 944 friends cannot help find a 911 (964) Carrera owner without a sunroof. Why because I know Porsche installed the relays in these regardless. They are mounted in the centre tunnel of the 911C4. There is a little panel on the passengers side, held in by two screws. Remove this panel and right in front of you is a relay. This is the sunroof relay.
These fuses installed are slow to blow. When they do they pop.
To your question about airbags and the reset. All the German manufacturers have had problems with airbag installations. Mercedes still to this day. They, Porsche made the first airbag installations very complicated. This is quite normal however. As time went by and the systems improvced, so did the installations and monitoring. Again no problem for me because I do not have airbags.
Reading about your electrical tests. all seems fine to me,
Ciao,
Adrian
911C4
944

PS: My wife has airbags in her Audi and that had to be fixed a couple of times and this is a 1994 model.

IceShark

Thanks for the comments Adrian.

I suspected the fuses were too slow, basically junk if the other manufacturers cut things like electrical current robustness too close to the bone.

As far as other relays, that is a very frustrating business. I got a fine USA manufactured (at least I think) generic electronic flasher relay for 10 bucks. I did see one for $6 but it was made in China, a quality issue and those guys want to kill us in the USA, so forget that.

I be darned if I can figure out the more complicated relays and cross reference to a v-dub or audi.

Airbags systems are a pain in the ***. So much so that I now have the warning light reset sequence down by memory.