Mark is right.
I ignored the flashing  light many years ago, much to my later expense.
Apparently the oil was so hot that the oil pressure was low.  Regrinding
a crank, 4 new rods, new bearings and a gasket set (and LOTS of hours)
made it like new.
I think ALL race cars have lights in addition to the guage. All 356
Porsches had lights only. Things have changed a lot since then, but
356's had to be one of the most ahead-of-their-times cars ever built.
Al Brase

mark drillock wrote:

> Actually, it does not work quite the way you say. The dual oil switch
> circuit board never ignores the low pressure switch. It does ignore the
> high pressure switch when the engine is at lower rpms, below 2000 or so.
> Above that rpm it watches both switches and blinks the LED if either has
> a bad reading and also rings the buzzer if it is the high switch with a
> bad reading. As for a gauge being preferred to an idiot light, no way. A
> good supplement perhaps but not a substitute. I have had my engine saved
> by the blinking light. Traveling on the freeway one night with my SO
> driving, she says "what's this blinking red light?" I lean over, look,
> and yell pull over! I get out and find oil dripping off the back of the
> Van and no oil reading on the dipstick. A valve cover gasket was leaking
> on one side. Not a big leak but enough to drain the engine after a few
> hours of highway driving. I had checked the oil level at the last fuel
> stop and it was fine then. Do you think she would have noticed a low
> pressure reading on a gauge in time to save the engine? No way. A
> suddenly blinking red light, yes. I drove that engine for many years
> after that event.
>
> As for disabling the tach feed when using the later cluster there is a
> better way than cutting a trace. Simply bend the male pin over a few
> millimeters. So the connector misses it when put in place. There are 6
> pins in the connector on the back of the speedo, a group of 2 and a
> group of 4. The outside pin of the group of 4 is the tach signal to the
> oil warning board. Bend that pin to the outside and push the connector
> back on the remaining pins. Then only the low pressure switch will be
> monitored.
>
> Mark
>
> John Bange wrote:
>
>>
>>
>> Well, ideally you'd want to go in and cut the trace feeding the tach
>> signal
>> to the "dynamic oil pressure sensor" circuit board. Above 2000RPM the
>> board
>> ignores your .3bar sensor and just watches a ground loop where the .9bar
>> sensor should be. Cutting the RPM signal to the board would make it
>> think
>> you were always below 2000, thus keeping your .3bar sensor "in the
>> loop" all
>> the time. Realistically though, it shouldn't matter. If your oil
>> pressure
>> drops far enough to trip the .3bar sensor when you're above 2000RPM, the
>> light is essentially a "pull over and swap engine" signal. I mean,
>> maybe if
>> the pump was sucking air because of a major leak blew all your oil
>> out you
>> might be able to pull over before your engine goes feet up, but more
>> than
>> likely not. The idiot light is better than nothing, but not much.
>> Personally, I think an oil pressure gauge is the only really sure way to
>> know when things start "heading south". The Vanagon oil light reminds
>> me of
>> the TEMP light in my awful 82 Olds Cutlass-- it really should have been
>> labelled "THAR SHE BLOWS".
>>
>>
>>
>>
>> --
>> John Bange
>> '90 Vanagon - "Geldsauger"
>>
>>
>>
>>
>