Oil pressure switch operation

[Sci85]

Working through my wiring harness and have a question. My oil pressure warning light does not light when the key is turned on. During troubleshooting if I remove the g/y wire from the sensor and ground it on the case, the indicator bulb lights. It was working fine a couple of weeks ago and just started exhibiting this behavior since I've been messing with the wiring.

So, how does the pressure switch work? Is the switch suddenly bad or do I have a grounding issue and if so, where should I look first?

Thanks,
Sci85

[Nessism]

The pressure switch is a simple spring loaded metal plunger. With no oil flow the metal plunger contacts the engine case, providing a ground path for the light. When there is oil flow, the plunger is pushed off the case and the ground path is interrupted.

[Sci85]

Okay that helps thanks a lot. So, since mine is not working, can this part be cleaned and salvaged or does it require replacement?

[Nessism]

Okay that helps thanks a lot. So, since mine is not working, can this part be cleaned and salvaged or does it require replacement?

Bet you there is nothing wrong with it. I have a few spares if by chance it's messed up. Take it off and take a look. Very easy to R/R.

[Sci85]

Yep, you were right. I took it out, manually plunged it a couple times, put it back in and sure enough she works. Thanks Nessism!

[GateKeeper]

YAY..........

best kind of fix.......Free.........

[Missile99]

Cool Sci. A simple fix is nice to have. I was wondering where you'd been.

Mine stayed lit constantly so I went through the troubleshooting steps of making sure there was good oil pressure. The plunger on the switch worked fine but the brass washer that grounds when there is no pressure appeared to be grounding to the side of the case when there was pressure. It almost looked like there were scrape marks but I couldn't get close enough to see. I took that washer/plate off and reinstalled it. Then put on a gauge from Renobruce.

The oil passage thread: http://www.thegsresources.com/_forum...d.php?t=193010

[Sci85]

Yep, still here. Summer has been busy. I've been racing on the weekends and travelling during the week so time has been scarce. I took a good flight over the bars this weekend and think I broke some ribs so looks like I may have a few weekends free to pour into the zook now. I'm at the point of rebuilding the carbs but waiting on parts. Then the expensive stuff happens. Bodywork, paint, new blinkers, rear shocks. Painful ribs and painful wallet at the moment...

What is this gauge you refer to from renobruce?

[Missile99]

Oh the ribs. Bummer. The racing sounds like a bunch of fun though.

It's a nice small oil pressure gauge that mounts to the right side. You can see it on your project thread, last page where I posted pictures to show the shocks. It sits nicely just above the ignition cover. I could have bought a stock replacement switch for $15 or so but I'd rather see numbers than wait for the light to come on. Ours is the low pressure and the 550 is usually running in the 6-7 psi range at around 6ooo rpm if I'm remembering right.

Renobruce's thread:

http://www.thegsresources.com/_forum/showthread.php?t=151617&highlight=oil+pressure+gauge