Oil Light

[egsols]

Bike is running good and I noticed the oil light never comes one. I pulled the cover and found the reason. No bulb. Guess PO or one of his numerous mechanics had fixed an oil light problem by removing the cause, the bulb. I replaced the bulb and sure enough it lights up and stays lit.

I pulled the wire off the sensor and the light turned off. I then pulled the sensor. Looked clean. Attached the wire back to the sensor, grounded the sensor and blew air into sensor using vaccuum gauge. Light went out. Figured this means sensor and wiring okay. Checked oil level, ti was at top line in window. Fired up beast and watched oil level drop. Guess I got pressure or at least the pump is working.

What should I do next? Is their an easy way of checking the oil delivery to the heads?

Scratching my head again.

Ernie

[petejw]

Hi egsols,
if u werent getting oil to the top end, u would
definately here it, the top end would be noisy,

if u disconnect the wire from the sensor, the lite
should go out, if it doesnt then its grounding somewhere.

if u then ground the wire the lite
should come on.

usually if they play up its the sensor.

quote:
"I pulled the wire off the sensor and the light turned off. I then pulled the sensor. Looked clean. Attached the wire back to the sensor, grounded the sensor and blew air into sensor using vaccuum gauge. Light went out. Figured this means sensor and wiring okay"

I dont really understand wat u meant by the above.
the sensor can look clean doesnt mean its not faulty.
not sure how u blow air into the sensor using a vac gauge?

[John]

The oil pressure sender is nothing more than a normally closed switch, that is opened under pressure, and closes when the pressure falls below a preset psi. It either soulds like you have a bad sender or no oil pressure, but I would bet on the sender. You could probably go to an auto parts store and buy a 5 psi switch for it. The switch looks just like the one in my 3.0 L 96 Taurus. Hell, Andreas Weiss probably has a pile of them...contact him for one.

[mro]

Had read here it can also be a problem with brake light.
Pressure good? then might try check/clean brake light socket/connectors. He had written that after he had changed the bulb, oil light worked normally.


mro

[mro]

BTW, multi-meter...
set for checking continuity.
Engine off and wire off pressure switch.
One leed to switch and other to ground on engine/frame
Should have continuity (switch "closed")

Start engine, same check, NO continuity (switch "open")

Get different result than above...switch problem
Switch good, then wiring or brake light problem.


mro

[egsols]

Hey Petejw,

My vacuum pump is set up like a politician, it sucks and blows. I can use it to create vacuum, for bleeding brakes or for applying pressure. There is a collar on the end of it that slides back and forth to cover the intake/vent holes.

I don't think I explained it right. What I meant by the sensor looking clean is that it wasn't covered with old oil and the hole wasn't obstructed. Looking back, when I pressurized the sensor some oil came back out when I let off the pressure. The oil looked really, really clean?

Hey John, Mro

I used an adapter on my pump to fit inside the hole on the sender. As soon as I created more than 2-4psi in the sender, the light went out. When I let the pressure off the light came back on. Doesn't this mean the sensor is working?

Does the oil go past the sensor before it goes throught the tube to feed the heads? If it does should I pull the line at the head and check for oil pumping out there?

Ernie

[mro]

Remember seeing the oil flow diagram but at the moment can't remember senders posistion (CRS)

Fired up beast and watched oil level drop

If the passage way was blocked engine should start sounding like a cement mixer and after a minuet or two serious damage would have occured.

Have you checked the brake light and associated wiring?


mro

[egsols]

Hey Mro,

Checked brake light, all looked good, replaced bulb anyway with a 2357 (i think) I know it was a something ##57 that's brighter than a 1157. Tail light works, brake light works with both front and rear and doesn't affect oil light.

I agree, I think it would sound pretty bad if it wasn't getting oil to the top.

I think I might run the bike for a bit then pull the sensor to see if the end is wet with oil, at least that my tell me if oil is getting to it.


Ernie

[mro]

Can pull bulb in dash and with wire off sender
Check w/MM from wire to ground (engine or frame) if you have continuity then somewhere that circut is grounding when it should not. If that checks good and brake light circut good sorta leaves the sender as likely suspect.


mro

[John]

What you should do, if there is this much doubt, is to install a mechanical oil gauge and measure the pressure that way. I believe the port for the oil switch is 1/8 pipe thread. You can tap in there or in the oil galley on the left side of the engine.
Your test procedure was good, and from what I read the switch is good.

[oseaghdha]

Seems like

You isolated the problem to the sensor/oil pressure.
If you remove the sensor and start the bike, you should have oil coming out the hole. Messy, but then you know there is flow.
If you can get a rubber adaptor that you can wedge into the hole, you may be able to hook your gage to it and check the pressure. Don't know what the limit is on the sensor. You may have low pressure, but still be getting flow. I would try to scab a gage on it for sure, but not sure what fittings are required.


What John said.

[TopCatGr58]

Hey Ernie,

Your sender unit sounds like it's working fine, test light went out when you applied a small amount of air pressure to it! You haven't burned up your engine, so you're probably getting oil to the topend!

I remember someone posting about how some oil or such got around where the sender wire connects to the sender, and was bypassing the internal switch, and grounding to the outer sender case, keeping the light on all the time!

Double check where the wire connects to the sender, clean thoroughly, reattach wire and ensure that it's not grounding to sender case, and ALSO check the wire for lost insulation somewhere along it's length, that could have been rubbing against the engine case when everything is installed and could have also been providing the needed ground to light the warning light even though the switch may be working properly!
T.C.

[egsols]

Thanks guys,

I think I'll remove the sender and replace with a guage with perhaps I make permanent and eliminate the "idiot" light. My main worry is if I do have lack of pressure. I guess that since it hasn't blown up yet and who knows how long ago the bulb was pulled, it probably is okay.

I'll let you the results once I get a guage on it.

Ernie

[egsols]

Went out to garage yesterday with extra large coffee, full pack of smokes and lots of ambition. Rechecked sensor on work bench with pressure guage and ohm meter. Sensor okay. Checked cont. on sensor wire back to bulb, no grounding issues. Pulled headlight to check additionally wiring. Then I thought of something. I remembered turning bike on to check tail light, came on with key, okay. Then turned key back to lock and all the way back to park. No tail light. Checked wiring to ignition, okay. Started tracing wires back to light checker, all okay. Traced wiring from tail light forward, bingo. P.O. had replaced fuse block and had rewired taillight directly to headlight fuse! Oil light was staying on because the light checker was bypassed! Re-wired circuit correctly, among many others, every works awesome now!!

BTW, I was using the wiring diagrams in the Clymer, and noticed that they leave out some detail that the Haynes manual has and vice versa. This goes for the rest of the manual as well. Its helpful having two manuals with different opinions.

Thanks again for all advise.

If you read this TC and if you have any more fuse blocks left can you PM with details on how to get one. I think I'll redo the one the PO had done.



Ernie

79XS1100SF

[petejw]

great stuff,
well diagnosed, electricals can b tricky at the best of times.
always good to hear a happy ending.