electrical problem at fuse 10 in 1975 bus

[cutter57]

Hi. This might be lengthy, so bear with me, please.
I have a 1975 bus, Riviera conversion, with a beetle motor in it. Runs great.
My windshield wipers and stereo stopped working Monday. Here's the story.

1. For as long as I have had a replacement headlight switch, about 4 years, the instrument panel lights would sometimes go out and I could get them back by rotating the headlight knob left and right. No big deal

2. Last week, I noticed that if I turned on my headlights while my stereo played, the stereo would die momentarily and come right back on. I ordered a new headlight switch.

3. My stereo is wired to Fuse #10 since installed 3 years ago, in place of the long-gone rear window defogger. Shares the upper side of fuse #10 with the wire to the windshield wiper switch.

4. Monday, while driving home in the rain, I decided to turn my headlights on while my stereo and wipers were on. The wipers and stereo quit and I momentarily smelled a whiff of smoke and I quickly shut my headlights out. Wipers and stereo remained dead.

5. Wednesday, I removed instrument panel and replaced my headlight switch and installed my new clock (yea!). I looked at old switch and wires attached to it and saw nothing wrong. Placed cable back on battery and checked it out. Instrument panel (and clock) lights came on, as did my side marker lights. Still no wipers or stereo.

6. Got my wire diagram out. Traced stereo wire back to fuse block, confirmed it is connected to same side of fuse #10 as wipers. Fuse was not blown. Replaced it anyway and still no wipers or stereo. Checked headlights and they were dead, too. My marker lights, interior and instrument panel lights all work.

7. Looking at wire diagram, I saw a black and yellow wire labeled "X" comes from ignition switch to bottom side of fuse #10, with additional black and yellow wire going from same side of fuse to the "X" post on the light switch (and then to the headlights). I traced this wire from fuse block to light switch and found no breaks, burns, etc. Contact points look pristine. I traced the other "X" wire from fuse block back to connector at ignition switch. Again, all looks pristine. I disconnected the plug from the ignition switch in steering column and still find no burns, wire breaks, etc. The prongs on the ignition switch itself are shiny and clean.

Any ideas on what my problem could be and/or ideas on what to do next to diagnose it. The bus starts right up and it seems the other wires (in the diagram) coming from the ignition switch have no problems at their ends; only the switches fed by the "X" wire from the ignition switch are affected, on either side of fuse#10.

any help would be appreciated. Thanks for reading all this
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[Wildthings]

The "X" circuit is a load reduction circuit that turns off high amperage loads while the key is in the "start" position. Otherwise it functions the same as the #15 circuit. Maybe time for a new ignition switch.

The #7 fuse is typically used for the stereo, but use the "X" circuit and a relay if you are really pumping out the wattage.

[busdaddy]

Sounds like it's time for a new ignition switch to me.
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[cutter57]

Thanks Wildthings and busdaddy. My stereo is basic with no amplifiers, etc. Has not been a problem until now. I was thinking it might be the switch itself, so looks like I will do a search on switch replacement and start there
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the enemy of good is better.

[SGKent]

I concur but did you check ALL the fuses to see if any were bad? You could have more than one thing going on - for example a shorted tail light etc that took out another fuse and the ignition switch.
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[Wildthings]

Stock switches are still available and about the lowest priced switch out there. If you are running anything with a higher amp draw consider adding headlight relays to protect both the ignition and headlight switch.

[cutter57]

Update: I was able to get an ignition switch today. Installed it and everything is working fine. SGKent, I did check the other fuses, too. Thanks everyone for the help.
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the enemy of good is better.

[alman72]

thanks for the update. threads with no resolution are so frustrating. Did they fix it? sell it? crush it? die in a tragic work accident?
Kudos OP

[KentABQ]

[cutter57]

Wildthings, sorry it took so long for me to reply. I got my switch locally (an hour away from me), at Avery's Air Cooled Auto Parts in Kelso, WA. I did find the appropriate switch available at cip1.com and Wolfsburg West, but I needed to get the job done yesterday, so I could not wait. My switch is new, but if you are ever looking for original used parts, Avery's does ship, I think. I picked up some VW hubcaps for my 66 beetle while I was there since I am sick of my re-pops rusting so quickly. They are not perfect, but they will shine up nicely I think and they are not rusty...not even after 50 years.
_________________
the enemy of good is better.

[cutter57]

Oops, should have addressed that last post to KentPS...sorry
_________________
the enemy of good is better.

[Wildthings]