VW Bus idiot light mis-wiring

[loosecaboose]

I have a 1961 VW bus. The previous owner did a horrible job wiring it, even burnt through the oil pressure cable. I succeeed in re-wiring the whole bus and now everything works except to the two idiot lights indicating Generator and Oil. I am 99% sure it is a wiring issue because the battery charges up fine and the engine is not running hot and I've been riding 1000's of miles on the motor that is tuned regularly. I don't think it is the sensor but decided to go ahead and replace it anyway. So I'm sure it is wiring.

1. First time bus owner first time wiring. But the wires are all mixed up and I was just happy to get a wire coneccted to the right places for starters so colors wont tell me anything. ie ground the brown wire etc.
2. The oil pressure light and the gen light are synch'd up. meaning that either both glow or both don't and they flicker in synch.
3. the oil pressure light doesn't come on when i put the key in 1st position (on) but not have the engine on. Both lights come on and stay on when the engine is on, but only after a it is reved the first time do they both come on.
4. they turn off when i turn the engine off.
5. if i disconnect the oil pressure wire from the sensor and ground it, the light doen't come on. same with the generator.
6. if the generator wirre is disconnected and not grounded, niether light will turn on, no matter what i do with the oil light.
7. i'm certain the oil wire and gen wire aren't crossed. i checked with my volt meter and they are running independently and even in different insulated wire clusters.

I have a hunch i have to ground a wire, but i don't know what i have to ground. I understand the ground is the body of the car, but whre does the other end of the wire go? somewhere in the inst cluster or somewhere in the back by the oil sensor an generator?

thanks!

[Marc]

As you've surmised, the warning lights are supposed to come on when their respective sensing wires are grounded. In order for that to happen, there must be power applied to the "shells" of the bubholders.
Note the little black wire on this diagram that comes from Term 15 on the ignition switch - it supplies power to the bulbholders of K2, K3, and K4 and I suspect that's where your problem lies.



On the Bus speedo the high beam indicator lamp is at 6:00 and the t'signal indicator lamp is at 12:00 - opposite of the Bug speedo. So, for the Bug the three lamps that need power to their shells are all in one cluster at the bottom that has a single tab for the power wire, but on the Bus they're scattered around the speedo.

[loosecaboose]

You hit the nail on the head! Thanks! Now both the Red Gen K2 & Oil K4 come on when engine is off but ignition is on (in 1st position). To clarify: Both these lights should be on when ignition is on and engine is off?
Dont know yet if they both turn off when engine is on cuz I think some wire is shorted somewhere in the mains, bcuz my battery is dead. Starter turns but engine doesnt start. Trickle charging overnight and hopefully the bus will start. It ran fine yesterday.
Next Question. If i run juice from my charger to the Batt's + terminal and touch the charger's neg- to the bus body and there are sparks, that indicates a short somewhere right?
If yes, then would next step be tracing?
Final Q: managed to find a brown wire disconnected behind the instrument cluster while trying to connect the black wire to the damn D15 clip. Traced the brown wire to the underside of the bus and it was just dangling freely. I attached that end to one of the cross beams (chassis ) to ground it but where do i connect the other end behind the inst cluster? In oyher words, how do i ground the instrument cluster? Though everything seems to working: flashers, dash lights, idiot lights, headlights and highbeams. So not sure what this infamous brown wire does exactly.

[Marc]

...To clarify: Both these lights should be on when ignition is on and engine is off?

Yes. Let me take this moment to chastise you for driving even 10 feet, let alone thousands of miles, without those warning lights functioning properly. They're all you've got to monitor the engine with until the expensive noises and smoke start. Besides telling you that the generator's working, when that lamp's out with the engine running it means your fanbelt is present - pretty important on an aircooled engine. It can take less than a minute with the oil pressure light on before the engine bearings are damaged, too. But the lights need to be functional before you can assume all is well because they're off - always look to see that both lights come on before starting the engine. If not, investigate and correct before you drive off.

...my battery is dead. Starter turns but engine doesn't start...

I presume you mean that you ran the battery dead while trying to start. Switch the key on and see if there's power at the + (Term 15) terminal on the ignition coil, you may have disrupted something while working on the instrument lights. On your bus, "key-on" power should be going to the fusepanel, and from there back to the coil (all via black wires). The terminal at the fuespanel where two black wires go is just a junction point, there is NO fuse protection for the coil so if that wire ever gets grounded back in the engine compartment the whole harness can get smoked again. Assuming you have things wired correctly, the fact that the signals, etc. are working means that power is making it from the ignition switch to the fusepanel which should exonerate the ignition switch itself, but by your own admission this wiring job is "creative" (to put it politely) which limits my ability to troubleshoot it from a distance.

Next Question. If i run juice from my charger to the Batt's + terminal and touch the charger's neg- to the bus body and there are sparks, that indicates a short somewhere right?

No, that's normal - the charger's sitting there with voltage available, when you make the final connection to close the circuit there will be sparks. To avoid that, don't turn the charger on until both leads are hooked up.

...how do i ground the instrument cluster? Though everything seems to working: flashers, dash lights, idiot lights, headlights and highbeams. So not sure what this infamous brown wire does exactly.

It's grounded by its mounting screws, they didn't start adding dedicated grounding wires until `68 IIRC. The only brown wire that has any business in that neighborhood is the one that runs to the horn. The horn has power to it 24/7 (on a Bus) via a black wire with yellow stripe, and sounds when the brown wire is grounded up at the horn button.

[loosecaboose]

Just want to say you rock!

Can't wait to get home and check and see if the On wires junction at the fuse panel, i think they just run directly to the back though.

I hear the starter noises when i turn the ignition to start but it doesn't, the engine doesnt want to kick in -though it's trying. I disconnected the terminals and running a trickle charge today and will wait and see if i get it going.

Agreed it was a dumb move and very ignorant. had no idea of the importance of those lights (now i know why they are called idiot lights) just thought it was similar to the check engine lights in today's cars. I bought it in New Orleans and drove it back to Cali like that. I checked the oil eery morning and did a valve adjustments and timing checks all the way. caried spare fan belts which i never had to use. Now that I'm home I'm learning this bus, which I just love and can't imagine driving anything else again and working to get these two lights sorted!

I plan to re-wire the bus properly using all the correct colors, guages going to the right place and clean up that dangling fuse panel next, but for now, i just wanted to make sure there that things work when connected and to stop the leaking oil and trans oil.

Thanks again Marc!

[Marc]

If you're going to have to do extensive rewiring you might want to consider updating/upgrading a little while you're at it. I suggest you wire it as though it were a `62-`65 with an 8-fuse box for improved load distribution. You won't get full points at a Concours d'Elegance, but it'll be easier to live with.
If you want it to have hazard flashers, don't use the ridiculous `66-mid`69 arrangement that needs an expensive, complex 9-prong flasher relay. Instead study the `69½-`71 setup that moves the complexity to the 4-way switch and gets by with a simple flasher - it's possible to insinuate that system into any earlier bus, and if you do it using parts and stock-colored wires from a ~1970 donor it'll be easy to figure out for anyone who needs to work on it in the future.
http://www.vintagebus.com/wiring/bus-62-usa.jpg