Please help with STRANGE electrical problem

[boyt911sc]

Originally Posted by John Pedersen

Tony
1). Ignition switch OFF: Do you have power @ 87a (FP relay socket)?

No power to 87A or any on FP socket
2). Ignition switch ON : Do you have power @ 87a ?
Yes to 87A also 86
Use a test light/lamp for the above tests and see what you have.

Install FP relay back:
1). Ignition switch OFF: Does fuel pump run? If NO, lift the air sensor plate and see if pump runs.
No to both
2). Ignition switch ON : Does fuel pump run? If NO, lift the air sensor plate and see if the pump runs.
No and yes when you lift the plate
Also, re the generator lite , I don't se a diode on back and oil, gen lite egr., park brake lites stay on after key is off and the CDI is singing!
The car starts and runs fine with a good black relay in FP socket but turn key off, keeps running untill you pull FP relay out, but you need to remove the Neg from the battery to kill power to other lights or CDI, aftr you do this all is fine until you turn key on again!
John

John,

Answer sheet:
1A). NO
2A). YES

1B). NO; NO
2B). NO; YES

All your answers are the same from what is expected from a good working CIS system. I would put my money on your ignition switch .





I'll take another look at the wiring diagram and search for the cause of this anomaly.

Tony

[zweistein]

check this also:

http://forums.pelicanparts.com/porsche-911-technical-forum/266216-electrical-problem-lights-knob-turns-fuel-pump.html#post4603230

good luck

Andreas