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Thu Oct 15, 2020 7:12 am

1967 VW Beetle, mostly original
205,000 miles.

All electrical systems operate normally...head and tail lights, interior light, horn, radio, starter, etc.....except the green oil pressure light.

I’ve noticed recently when turning the key to the on position of the ignition switch....the red generator light always comes on, however, the green oil light doesn’t always come on. When it doesn’t light, I turn the key back to the off position, remove it from the switch, insert it again into the switch, and turn it again to the on position, and the red and green lights both come on. Turning the key in the switch also feels kind of notchy rather than smooth. I’ve not yet experienced any non start or die out issues, however, I’m concerned that will be next.

The green oil light bulb is good as is the pressure switch.

Does this symptom indicate a failing ignition switch?

Thu Oct 15, 2020 9:17 am

Could just be a loose bulb holder/electrical connection there. How's the engine end? Nice tight clean terminal? Doesn't sound like a switch issue to me.

Thu Oct 15, 2020 11:25 am

FL-Frank wrote: ... All electrical systems operate normally....except the green oil pressure light...Does this symptom indicate a failing ignition switch?

No; if the ignition switch fails to bring oil idiot light on, then how could it bring everything else on? Use a test instrument (anything from a crude homemade bulb with solder'd wires and alligator clips, to a VOM meter with pointed probe), and trace out the circuit.

Thu Oct 15, 2020 2:46 pm

All the switch does when you turn it to RUN is give voltage to the fusebox terminal for switched power. The same function should light both oil and gen lights. If one works, it's not the switch, it's elsewhere in the oil light circuit.

Thu Oct 15, 2020 4:34 pm

The ignition switch can fail two ways. One is that it won't turn the starter over. This can be intermittent or a hard fail. Two is that you lose power to the fuse box and thus the ignition coil. Intermittent failure will result in your engine stopping at the most inopportune times and then you can start the car after a few tries or after a little bit of time. This can go on for quite some time or may just happen once and it's all over. I agree with what has been said so far that the problem is not with the switch.

Fri Oct 16, 2020 4:21 am

I replaced the ignition switch in my 67 about 3 months ago with a WW one. Before replacing, I went through 2 sets of points in 6 months and the black wire from switch to fuseblock melted! Not sure any of these were related to the switch, but 3 months later, no problems.

Fri Oct 16, 2020 7:37 am

Thanks for everyone’s advice.

I checked/tested/cleaned all of the oil pressure light circuit‘s connections, bulb, bulb holder, and fuse.

However, still experiencing intermittent operation of the oil light when turning the ignition switch to the position.

Next, I’ll try replacing the bulb holder, and removing the speedo so I can inspect and clean the speedometer bulb holder contact surface.

Sun Oct 18, 2020 12:43 pm

Make sure all the connections are making 'good contact'. You might even just switch the bulb with a known good one, just to see if it's the bulb at fault. You can remove the bulb holder and shine up all the connections, and check the bulb too. It could be a filament that is ready to break, and intermittently opening the circuit, then with some vibration, clings back to it's intended spot.

These little bulbs should be the same for the (G) and OIL as well as for the Hi-beam and speedo backlights. They aren't blue or green, but the gels in the gauge cluster itself are what give the lamp a perceived visible color.

That being said, you could just switch that blub with something else, to see if it's as simple as the bulb being bad - hi-beam for example.

I've had more electrical issues with my old vehicles after moving from a dry climate (Colorado) to a humid climate (Oregon). The moisture in the air seems to add a little extra oxidation/corrosion that gets in the way of tiny little bulbs and their holders. I've found that shining them up, tightening the contacts and using bulb grease (get a little packet at the auto parts store) seems to mitigate these humidity/electrical continuity issues. Living in Florida, you might be experiencing the same challenges.

Sun Oct 18, 2020 4:15 pm

If you want to test your ignition switch for high resistance then a voltage drop test will tell you the most about the health of it's internal connections.

On the back of the switch put the red lead of a DVOM to terminal +30 and the black on +15.

To measure voltage drop the circuit/component needs to have a load on it so turn the key to crank it over, start the car and observe the meter. You should not see more than 0.30 volts with the engine running. Also try it with the wipers on and your foot on the brake pedal to apply the max load you can.

If you have problems with intermittent no crank you can do the same with leads connected between +30 to +50, disconnect the ignition coil -1 to prevent starting, and observe the meter while cranking over.
Again no more than 0.30 volts.

Good idea to do a bulb/socket swap when the problem is active too.
However if you get the same result as before be aware all the bulb holder sockets are simply swedged into place in the speedo housing by being crimped over. Those connections can break down over time too. Check to see if they're loose or if you can wiggle them.

Mon Oct 19, 2020 9:57 am

As mentioned earlier, I’ve been noticing The past couple of weeks the key doesn’t turn smoothly in the ignition switch...it’s kind of notching...almost like it’s obstructed by something internal. This morning, the engine wouldn’t start...turning the key produced only a click. :(

Battery, starter, and solenoid tested good. However, Jumping the 50 and 30 terminals on the back of the switch spun the starter which apparently indicates the ignition switch is bad.

So, I’ve got a refurbished replacement switch on the way from Gabe. Once I install that, I’m curious to see if the issue with the intermittent green light persists.

Mon Oct 19, 2020 11:32 am

Take the ignition switch apart and clean all the contacts. I posted a thread showing how to do this. Good luck

Mon Oct 19, 2020 4:02 pm

I had this same oil light issue on my '63.
It seemed random.
The sender worked fine when the car was running or had been running, it just didn't always come on when I turned the key.

The wire to the oil switch had a loose connection/connector at the switch, fixing this made it a little more reliable but not perfect so I suspect that was one issue.

Replacing the oil pressure sender fixed it and now it works correctly.

Tue Oct 20, 2020 12:05 pm

I just replaced the ignition switch and the bulb and holder for the green oil light.

The ignition switch now operates perfectly with nice smooth key action.

However, the green oil light still operates intermittently when the key is turned to the on position. So, next I’ll try replacing the oil pressure switch. I’ll be a little disappointed if it winds up being the pressure switch since I just replaced it about a year ago...I got it from Wolfsburg West.

Tue Oct 20, 2020 12:32 pm

FL-Frank wrote: next I’ll try replacing the oil pressure switch.

Don't overtighten !!!

Tue Oct 20, 2020 1:11 pm

FL-Frank wrote: ....the green oil light still operates intermittently when the key is turned to the on position. So, next I’ll try replacing the oil pressure switch. I’ll be a little disappointed if it winds up being the pressure switch since I just replaced it about a year ago...I got it from Wolfsburg West.

Easy enough to test the circuit independent of the pressure sensor.

Next time the light does not come on, go back the the engine compartment, disconnect the wire off the sender and touch the wire terminal to ground. You can also use a jumper wire from the terminal to ground.

If the light lights, it's a bad sender.

If it doesn't, it's something with the power supply, bulb, socket, wiring etc as has been discussed.

Wed Oct 21, 2020 10:54 am

FL-Frank wrote: I just replaced the ignition switch and the bulb and holder for the green oil light.

The ignition switch now operates perfectly with nice smooth key action.

However, the green oil light still operates intermittently when the key is turned to the on position. So, next I’ll try replacing the oil pressure switch. I’ll be a little disappointed if it winds up being the pressure switch since I just replaced it about a year ago...I got it from Wolfsburg West.
When the OIL lamp next fails to turn ON when you rotate the key to the ON/RUN position (before starting the engine)... walk around to the engine compartment and gently disconnect the wire from the oil pressure switch and ground the end of the wire to the case. Does this turn the OIL lamp ON? This confirms thepower source, bulb and wiring are good.
Reconnect the wire to the switch, does the OIL lamp remain ON or turn OFF? If OFF, try tapping on the switch body and see if you can get it to turn ON.
All the switch does is ground the wire when the pressure drops below a set point (~5psi). If the switch internals are getting stuck, you need a new switch. If grounding the wire does not turn the OIL lamp on it suggests a problem with the wiring or possibly the bulb filament.

Wed Oct 21, 2020 1:12 pm

Thanks again for everyone’s advice!

Here’s where things stand....

After the engine has been off for At least 5 minutes or so, both the red and green lights light when the key is turned to the on position, and both go out once the engine has started.

However, after the engine has been running and then switched off...if I immediately turn the key Back to the on position, only the red light lights...the green one doesn’t.

With the key still in the on position, and only the red light lit, I Disconnected the wire from the oil sending unit and grounded it, and the green light lit.

Next I Replaced the sending unit with a new one from WW (in addition to replacing the bulb and bulb holder earlier). I Applied dielectric grease to the spade connector, and crimped the connection tight.

After all of this, the green light still doesn’t light immediately after the engine has been running, but it does light after the engine has been off for several minutes.

Any other suggestions?

Wed Oct 21, 2020 2:06 pm

Residual oil pressure? (as in some sort of clog keeping it up)

Wed Oct 21, 2020 2:13 pm

MrGoodtunes wrote: Residual oil pressure? (as in some sort of clog keeping it up)

That would be my guess. I would pull the oil relief valve and make sure it moves freely.

Thu Oct 22, 2020 2:40 am

splitjunkie wrote: MrGoodtunes wrote: Residual oil pressure? (as in some sort of clog keeping it up)

That would be my guess. I would pull the oil relief valve and make sure it moves freely.

Although I change the oil every 3,000 miles and the engine doesn’t run hot....I had the same thought.

Looks like I’ll finally get to use the drag link socket that came in the tool set I bought 40 years ago :D