rockatansky

Hi. After removing and fully checking the printed circuit at the dash board and the central warning unit, fixed some things, but I still have some issues with 4 warning lights not coming on at the dash board.

Next I will follow the WSM procedure for every sensor, but first it advices me to:

"...Pull off terminal 4 ignition wire at the distributor and connect it to ground like the cross member bolt. Then turn the key to activate the starter."

Could anybody extend a bit this explanation and tell me the reason of doing this previously of checking every sensor wire?. I don't want to fry anything, and electrics scare me a bit.

Ducman82

what lights?

rockatansky

Those not comming ON even at the pre-crank position of the key are (my car has them in German): In the left dial, WA.WASSER (windshield water), SCHLUSSLICHT (rear lights), BREMSLICHT (brake lights), at the right I'm missing OELSTAND (oil level). Thanks Ducman.

rockatansky

Ok, I think I know now why those 4 warning lights are non functioning. Starting at 1980 Porsche offer as an EXTRA, the central warning unit which is part number 928.641.602.01. If you don't pay for that extra, they install what they call an 'Adapter', part number: '928.641.601.01'. The difference between them is that the adapter (which is the part that I have installed in my '80), is a limited version of the circuit board and didn't warn about those 4 warnings that I'm missing at the dash.

This is extracted from the 928 WSM:

"The central warning system is only available as optional extra (M) equipment in Type 928 cars beginning with 1980 model. An adapter is installed standard in the same housing instead of the central warning system. The monitored functions are limited to:

1 - Oil pressure
2 - Brake circuit failure
3 - Brake fluid level
4 - Brake pad wear
5 - Parking brake
6 - Coolant temperature
7 - Fuel tank reserve

There is not a red acknowledgement button in the center console then.".

This matches my car. I don't have the acknowledgement button. Some days ago I remove the dash board and feed the bulbs and saw those warnings lighting there, so I thought that they should lit when turning the key. If I understand correctly, in my car, the rear lights, the stop lights, the windshield water and the oil level are not being monitored...

Now I'm wondering what would happen if I buy an used central warning unit and install it instead of the 'adapter' I have. Will it work?, would I have those extra functions added.

Hope someone can shed some light...

SQLGuy

I'd think not... you probably don't have the sensors for those items; and you may not even have the wiring that would connect them to the warning unit.

But, if you ever get one of the 928 watches, you'll need to upgrade to the central warning setup ;-)

Thanks for posting this, though. I had no idea CW was an option.

rockatansky

Thanks SQLGuy, I would check if I have the 'bulb check control box' that should be over the CE Panel, I think that control the rear lights and stop lights warning signs. What I could tell you now is that the wires that goes from the 'Central Warning unit' (in my case the 'adapter'), are there and switch on the signs at the dash If I feed them with voltage.

It will be great if only by plugin in a new Central Warning unit I'd get those extra features working, but I need to investigate before getting one. I haven't found any message at rennlist giving me any clues about it yet.

The reason of posting that paragraph from the wsm is because I'm sure that, like me, many people around is still thinking that they have some warning signs misfuncioning, and the thruth is that they have an adapter part, instead of the central waning (both are silver boxes with 2 circuit boards and a yellow and black connectors but...).