oil light w/ turn signal?, befuddled... Options

[vmills]

My oil light is flashing. It has done this before, and it went out after a little driving. But it's back and it's not going away after a little driving, and I'm not sure how it works or why it's flashing. It also has some peculiar behavior I haven't noticed before...

Firstly, it starts flashing when I turn the ignition on, before I start the engine. Is this normal? It wasn't doing this before. I thought the oil light turned on when the oil pressure was too low? When the engine isn't running there is no oil pressure...is this normal for it to be flashing before the engine is on?

Secondly, if I use a turn signal while it's flashing, the oil light blinks at the same frequency as the turn signal. Same thing happens if I turn on the hazards. Is this normal? I've never noticed it before but it could've happened...

Also, is the car's oil situation so bad when it's flashing that I should stop driving it immediately? Can the light turn on steady (without flashing)? Oh, i'm so naive...thanks for any help

[bd1308]

that is NOT normal behavior.

i'd check the fuses.

if that doesn't fix things, I'd try to see if any paths are being crossed, IE the oil light grounding itslef out abnormally with the turn sig ground or something..

but then again i dont know anything...

[vmills]

Any idea on where these connections would be? Behind the gauges perhaps?

The weather today got really damp (in Wisconsin)...perhaps that has something to do with it or maybe i hit a bump and it jarred some things loose...

[bd1308]

hmm....what *I* would do is actually to check the back of the guages.

i have a therory, but let me preface it by asking you a question....

i) if you turn the key to on, what happens to the oil light? does it blink or stay glowing.

ii) if you start the car and let it idle, does the oil light go out?

iii) have you checked the oil level...?

iv) Take a gander at the fuses....are any warped or corroded? replace offending fuses, please dont replace with bullets.....true story BTW.

v) what happens to the generator light during this whole situation (the B light)....does it do anything or just stay unlit?

vi) have you or a mechanic messed with the brake system lately?

feel free to answer in similar manner.

[GS9146Driver]

The oil pressure light is illuminated by a ground provided by the oil pressure switch which has closed contacts when oil pressure is not present. You may have a wire grounded intermittantly. Sometimes weird things begin to happen as you described with the turn signals and hazards. To be really certain that it is wiring and you are not endangering the life of your engine, you could buy an inexpensive direct reading(tube connected) oil pressure gauge from your local auto parts store. Connect it up and run the engine, read the pressure- no pressure-shut it off!
I have the Haynes manuals and the electrical diagrams are very straight forward. BTW- what year is the car and what engine?
Geo (IMG:http://www.914world.com/bbs2/html/emoticons/beer.gif)

[vmills]

i) if you turn the key to on, what happens to the oil light? does it blink or stay glowing.
It blinks
ii) if you start the car and let it idle, does the oil light go out?
Nope, still blinks
iii) have you checked the oil level...?
I have checked the oil level, it's normal. Oil was changed not too long ago...couple hundred miles
iv) Take a gander at the fuses....are any warped or corroded? replace offending fuses, please dont replace with bullets.....true story BTW.
I see you've seen mythbusters...sweet show. I need to check these out (it's dark now and raining)
v) what happens to the generator light during this whole situation (the B light)....does it do anything or just stay unlit?
Generator light is on when ignition is on, but when I start the engine it goes off...this is normal, right?
vi) have you or a mechanic messed with the brake system lately?
Bleed the brakes a while ago...a month or 2


The car is a 1974 1.8l with stock l-jet fuel injection. I'll go get one of those oil gauges tomorrow I think...where is the oil pressure switch?

Thanks a ton, you guys are very knowledgable.

[bd1308]

look by the distributor...there is a hole in the tin with a greenish wire coming out of it....

thats your pressure switch.

[GS9146Driver]

Cool! I happen to own a '74 1.8.
Give me a few minutes to run down the wiring in the manual.
Geo

[vmills]

OK...i decided to go out in the rain and poke around. I found the oil pressure sender and it is DIRTY! Also, the wire is cracked and broken and if I moved it around in the right ways it would ground and blink and if I moved it in another way it went off. muwahaha...thanks for the help with that...now I just need to figure out why it blinks at the same frequency as the turn signals when it does blink.

Thanks...any more insight would be greatly appreciated...

[bd1308]

hmm

i was thinking that the brake warning light go entangled with the oil pressure light.

[vmills]

brake warning light doesn't light up much anymore, I have a feeling my friend disconnected it. My parking brake doesn't do much either, I need help with both of those issues too...

[GS9146Driver]

Okay, oil pressure switch is located inthe engine compartment just foward of the r/h cylinder bank. It screws directly into the oil cooler mount.
The switch will have a Green/Red wire connected.
That wire I believe will run to the engine circuit relay board on the l/h side of the engine compartment. It just runs through the board. Next remove the passenger side seat. There is a seat belt warning relay ( kind of large). Terminal "B" will have 2 Green/Reds wire connected. One is from the oil pressure switch via eng board, the other goes to the oil pressure light. use a ohm meter or a test light to trace down any shorts to ground. The oil light will have power applied from the 15 terminal on the emergency flasher switch Red/White wire.
Hope this helps.
Geo

[vmills]

That helps a lot, I'll look more into that tomorrow.

Thanks,
Vic

[GS9146Driver]

I edited the previous post... Flasher switch Red/white wire.
Geo

[vmills]

Thanks

[type47]

interesting.... my 74 1.8 L-jet has the "same" problem except that the oil pressure light glows dimly and the turn signal light glows dimly. i know the oil pressure is good because if i turn the key to ON, the light glows bright and when i start the car, will turn dim; it sometimes goes completely out. the turn signal never goes completely out. i think there is some ground fault or crossed wires somewhere.

[vmills]

yeah, i'm not sure about the turn signal thing, but i'm going to go clean up the sender and tape up the wire so it quits grounding itself.

thanks for all the help again

i'll let you know, type47, if i figure anything else out with the turn signal