This morning I got in my car and when I started it the oil pressure light stayed on, and faded out after about 30 seconds.

Then later, it came back on full time until I got to work and turned the car off.

Is this a bad sign?

The oil level is full. The engine wasn't running weird (well, any different than normal)

My water pump gasket is leaking and the fan is blowing coolant backwards on the wiring, so my shorting problem is worse (considerably)

Could the oil pressure light be on because of this?

Or should I look into it further?

Thanks,

Luke

/// You have good advise so far. The oil pressure failure light is a simple switch. If the internal diaphragm has started to leak you will also have the symptoms you gave. It could be either a short due to water, a short due to failed insulation, or a failed switch.

If you replace the switch do not over tighten. The threads on the switch are tapered and will reach a stop point. This will seal. If you attempt to snug up the switch with a wrench you will break that internal seal and the new switch will fail also.

Luke,

Take a look at the small wires behind the alternator. One is the oil pressure sender the other is the alternator failure test wire. If the insulation is crumbling you will need to replace wires or replace the wiring harness.

I had the same problem in my 86 244GL with only 118K miles on it! I ended up running two new wires along the heater hose for the oil sender and alternator instead of replacing the complete harness because the other wires did not seem too bad. I used nylon wire ties and soldered the wires to the connector on the firewall as required (cutting the old wire loose).

The harness will probably need to be replaced eventualy.

Good Luck,

Dom

P.S. Simon Eng, found on the board has nice wiring harness repair instructions if you want a copy email me.

I suspect your promblem is due to shorting - however pull the oil filler cap with the engine running just to be sure you have oil moving up top - no oil = turn off and start praying - oil, likely a short, bad sender or low oil presure.

Assuming it is a short I recomend doing the same - but when I did it I ran the new wire inside of several feet of vacuum hose. Why you ask - well I did this job three times in 75,000 miles - the cheap wire I used would get baked off by the heat from the exaust manafoild in about 10,000 miles - the last time I was fed up with the problem so I tried a proactive apporach to the problem - wire inside the vacuum hose.

For over 50,000 miles until I sold the car the wires inside vacuum hose never gave me any more problems. When I rewired this part of the harness I ran it all the way around under the engine to the junction point below the intake manifold.

Note that if the altnator light come on due to the short that it will not be charging your electrical system. This is ok if it comes and goes but be aware so you don't run your battery down. (I stopped many times along the interstate at night poking under the hood of my car on an 800 mile trip pulling the bare alt. wire off what ever it was grounding against - especally if it hit the oil pressure sender bare wire - then the idiot lights would lite up like Christmas in NYC.

> Could the oil pressure light be on because of this?

Yes.

> Or should I look into it further?

Definitely look into it further. Don't drive the car until you know what the problem is, or you could end up with a very large repair bill.