Mickey_928S

Just rebuilt my alternator and prformed the famed ground point clean-up hoping that all gremlings would find the high road. Alas... one remains! The dreaded flashing central warning lights. Before the rebuilt alternator I thought that it was as a result of low alternator charge. Now I am getting perfect charge and still flashings! I should note that the warning flashes only when the engine is warmed up trans in gear and foot on the brake at idle. As soon as I pull away - no more flashing. In park - no flashing.. with or without foot on the brake.

Has anybody else come across this? Any suggestions?

1983 928S

heinrich

That flashing mode is usually for very serious things like oil pressure etc.

G Man

Mine flashed when my brake fluid res was low.

Mickey_928S

I understand that the warning lights are for serious things. But are they not usually accompanied by another light indicating the offending component?
Why would now be getting a Flashing Warning Light without any other lights to explain the problem?

heinrich

Crect.So turn the key on in the am and see if ALL lights are functioning.

Mark

It is not uncommon for one of the warning bulbs in the pod to be burnt out (or loose).
Follow Heinrich's advise - make sure they all work when you firs turn the key on.

Mickey_928S

Is the little red light on the lowest range of the alternator supposed to come on with the rest of the warning lights? I assume so. If so, there is my problem. However, when the warning light flashes, the alternator guage still shows 11+ Volts and I have just had the alternator (Bosch) rebuilt. Could the voltage regulator be kaput?

WallyP

There are two probable causes for the light flashing as you describe.

One is the alternator output - with the engine running, the alternator should put out enough even at idle to keep the warning light off. The little warning light in the voltmeter should flicker as well if this is the problem. First thing to check is the alternator drive belt tension - the ribbed belt should be tighter than you would believe. On the Porsche belt tension gauge, the timing belt should be at 5.0, the alternator belt at 9.0!

The other possibility is low oil pressure. If the idle speed is a little low, the oil a little thin, or the oil pressure warning light switch a little sensitive, the light will flicker at idle. The little warning light in the oil pressure gauge should flicker as well if this is the problem.

FBIII

I think you need the low voltage light for the charging system to work in order for the alternator to fucntion.

Mickey_928S

The little oil presure light is lighting up on start-up (test) and holds strong at almost maximum during all driving conditions and idle. The voltage too shows strong in all conditions (although the little light does not show on start-up (test). Only the pod warning light flickers and blinks, not the consol reset button. During this flicker/blinking, no other lights show.
This warning light only comes on during driving, if I take my foot off the gas (under 30 mph) or car in gear and foot on brake. Not at idle.

heinrich

light or needle?

Mickey_928S

The needle holds strong

Mickey_928S

Interesting point regarding oil pressure. What happens if one reverses the wires on the oil pressure sending unit next to the alternator? When I pulled the alternator I noticed that the wires were gungy and the insulation cracked. I removed, cleaned and replaced the wires - now that I think of it, perhaps they were reversed. Looking at my oil pressure guage, upon engine start-up, it flies to maximum and stays there.
Possibly reversed wires? Possible cause for the light too?

heinrich

so you see ALL warning lights LIGHTS when you start up including belt ten; antilock (if you have it); engine oil; and the red pressure warning light for oil? where does the needle sit?

heinrich

it should be max till it warms then at 3 or 2 minumum.