My Fuse 11 has always had a short.

I've replaced the fuse panel itself with the blade fuse panel.

I thought it was the Interior light. I tested the continuity of the Black/Red wires...that's good.

Also tested to black and red on the hazard. For the moment, I have both disconnected.

Someone here suggested I look at the door switches...and think I am getting close.
There is a red wire coming off Fuse 11 going to the driver side door switch.

Was able to get that one. Looks to be in decent shape, the contacts look good. Tested the continuity with the switch open/closed. Seemed to be good.
Passenger side, the contacts were missing, the spring was hanging out of the bottom.

Both switches were the original black plastic, 4 wire models.
I ordered replacements, and they came in the two pin varierty (assume I'll need to solder on some new connectors for 4-into-2)

WHEN THE SWITCHES ARE REMOVED: all good.

Tested with the new switches-both and individually and kept popping fuses.


Any input would be appreciated!

Looking at the wiring schematic, there's a +12v coming from fuse 11 to the interior light that's always hot, even with ignition off. Makes sense because the emergency flashers and the clock (if you have one) are the other items that it looks like are fed off fuse 11. Does the interior light come on at all before the fuse pops? If not, then my guess is the interior light is wired incorrectly.

The light has a 3 position switch and 3 wire connections, the red/black +12v always hot, a brown that provides a constant ground for the light to turn on using switch on the light, and a brown/white that completes ground with the door switches when the light switch position is selected for it. I think the switch positions are up for on, center for off and down for on with the door switch, but I may have the first and third backwards, been a while since I've had power on our car. Anyway, if the red/black and brown/white happen to both be on the same side of the light's connectors, you'd definitely see a short and pop the fuse anytime a door switch was engaged. The red/black should be on the side of the light with the single spade connector and the brown and brown/white on the side with the 2 spade connectors. It'd be quick to at least check this out.

Dan

The light was out when I bought the car. So I bought a new one and it never worked. So right now I don’t even have it hooked up. Just so I can check if I’m getting power there. I

I thought those door switches were neg only (negative switching) and the hot wire went to the interior lamp on one side. Mine have one 4 lug and one 2 lug switch, IIRC.

Correct, door switches just complete a path to ground (if wired correctly)
should not have red wire to them.

Mine are both 4 connections.
2 red (hot)
2 brown (ground)

One of the reds goes to fuse 11.

I disconnected the switches.
The fuse holds.

Hooked up the interior light. Works!!

So.
The switches that I have are the new versions of this part. They only have two connections.

+1. I have found that many of the switches in these cars are ground wired ones.

Wiring for the door switches depends on the year of 914. Per George's 700 Tech Tips, "70-71 switches actually conduct 12 volts on the way to the open-door warning buzzer. Thankfully, this condition was corrected by 1972. It is suggested one not connect the red leads when reinstalling 70-71 door switches, but rather tape them off. These red leads could cause a serious short."

Thanks for sharing that. Learn something new every day. I'd just assumed it'd been the same all along and always refer to the '74 diagram, but yes, it does have +12 going to the door switches on the early cars according to the diagrams. That's what I get for assuming.

Dan

Yes!! That's gotta be it.

Mine is a 71.

I'm going to pull that wire out of the mix.

So, Just so I'm understanding...

I am going to replace those switches with the new 2 pole switches.

I will tape off the red wires.

Each side of the switches will only include grounds.

Correct?

Yes!! That's gotta be it.

Mine is a 71.

I'm going to pull that wire out of the mix.

So, Just so I'm understanding...

I am going to replace those switches with the new 2 pole switches.

I will tape off the red wires.

Each side of the switches will only include grounds.

Correct?

VICTORY LAP!!!!

Removed both the the red wires, clipped the wire at the Fuse.

Used both grounds.

Light works.

SUPER DUPER ADDED BONUS...now that Fuse 11 has power, my Hazards are now flashing proper.

Thank you all!!!!!!!

back to the dash renovation!

Good to hear you got it working! On my 74 I'm having a different issue with these switches. They are two connector switches with brown/white wires to each. One set has continuity to the other switch. The other does not and does not go to ground either. I've located the black red to power the cabin light but will only have a light if I turn it on at the light switch. The brown/white wires run up under the dash board where I can't see them. Am I correct in thinking these should run to ground to close the circuit when a door opens?

Rob

Hi Rob,
Here's the wiring diagram for a 74 with just the interior light.
Click to view attachment

Yes, door open causes switch to close to ground which would then provide a path of current for the light to turn on. So one set of brown/white wires feeds to the seat belt warning system, and the other set feeds to the interior light. Each of these are daisy chained from the left door to the right door according to the wiring diagram. Sounds like you've been using a meter already, so you could see which one of the two are actually running from the left door switch up to the light.

Good luck,
Dan

Thanks Dan: I have that circuit figured out. I took the Haynes diagram and added the relay contact numbers to the drawing Jeff Bowlsby put on the notebook site. There were a lot of inconsistencies but I'll clean up the new drawing and send it to Jeff. I went over to a friends today and looked at his relay hookup. It does not match the drawing either, but it works.
New door switches, lights and fuse block are due tomorrow.

Started the car yesterday to check all of the connections and it's all good! Just need to make a couple of new wires and I'm good to go. Of course now that it's running again I have some idling issues. I suspect my AAR rebuild might be at fault. Going to recon another one I have today and see if that fixes it.
Thanks everyone for you suggestions!
Rob