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Mon May 05, 2014 7:26 pm

Hey all. I tried to save myself the agony of asking and went through a search with no luck.

On my 60 standard fuse box, the far right one has blown a couple of times on start up leaving the alternator light on. Doesn't happen all the time so it's either something in the system or I've got the wrong fuse in there. I couldn't find the correct fuse ratings but I'm using the big red one in that spot which seems correct based on the pictures I've seen. It's stamped "16" on the fuse but I'm not sure if that's the rating or not.

If It's not a problem with the fuse then I'm meeting resistance somewhere in the system. Can you help me trace which grounds and connections I'll need to check? The bus has been out of commission for over a year so I'm hoping a little attention in that department will save me some future headaches.

Clue me in guys, this is kind of lame!

NAES

Mon May 05, 2014 7:40 pm

6 fuse screw terminal
8 fuse screw terminal
or
8 fuse push terminal fuse box?

Tue May 06, 2014 12:19 pm

Sorry. 8 fuse screw terminal

Tue May 06, 2014 2:23 pm

Does it happen if you pull the light switch on by itself? You might have a bad ignition switch that's shorting out internally.

Tue May 06, 2014 5:10 pm

Reading the schematic, I assume it's the fuse with the red wires going to it.

Should be a white 8 amp fuse.

Assuming all accessories are turned off, that leaves the only full time connected loads left: horn and front dome light as contenders for shorts. Unless something has been added or modified... Check the wiring going to these two devices.

If not that, then check the rear dome light switch and wiper switch connections.

This fuse should not affect the GEN (ALT) light at all, unless something's been modified. Stock dash indicator light wiring is unfused (no points, VW...) See: http://www.thesamba.com/vw/archives/info/wiring/1961bus_IdiotLights.jpg

Tue May 06, 2014 5:53 pm

Can you be more specific about what "on startup" means?

Before the fuse blows does the starter turn at all, or does the solenoid go click or nothing?

I would suspect a short in the ignition switch ->solenoid -> starter motor circuit since it happens on startup and not when the lights are operated or some other random time...

Wed May 07, 2014 8:08 am

If your system is wired like the schematic posted by Crofty, then you have a limited source for your problem.

As posted by mnengineer, the only things on the load side of the fuse are the horn and the dome lights. The ignition switch and starter are not fused and are on the line side of the fuse. A short in the ignition switch would not blow the fuse as the current to the switch does not flow through the fuse block. A fuse blows because too much amperage is flowing through it and, in your case, the only things that draw from that fuse are the horn and dome lights.

Please check your wiring at the fuse block and report back.

Wed May 07, 2014 5:14 pm

Cool, thanks everyone. Considering that i have no horn or working dome lights ill first check for rouge frayed wires!

Ive got some time this week. Ill report back with what i find

Thu May 08, 2014 7:48 am

olliehank47 wrote: If your system is wired like the schematic posted by Crofty, then you have a limited source for your problem.

As posted by mnengineer, the only things on the load side of the fuse are the horn and the dome lights. The ignition switch and starter are not fused and are on the line side of the fuse. A short in the ignition switch would not blow the fuse as the current to the switch does not flow through the fuse block. A fuse blows because too much amperage is flowing through it and, in your case, the only things that draw from that fuse are the horn and dome lights.

Please check your wiring at the fuse block and report back.

The horn and dome light are always hot - why would the fuse only blow when the key is turned?

Thu May 08, 2014 10:29 am

The best guess answer is that the wiring has been modified from stock, and the mods are biting back. Without looking, can't really tell.

Thu May 08, 2014 11:25 am

Quote: The best guess answer is that the wiring has been modified from stock, and the mods are biting back. Without looking, can't really tell.

This is what I am thinking...

Quote: The horn and dome light are always hot - why would the fuse only blow when the key is turned?

Like Telford said, the op needs to get in there and look around, but one possibility is that one of the red wires has been moved from the top of the fuse to the bottom. This would cause the entire starter current (mucho amperes) to run through the fuse. :shock:

Thu May 08, 2014 6:40 pm

crofty wrote: olliehank47 wrote: If your system is wired like the schematic posted by Crofty, then you have a limited source for your problem.

As posted by mnengineer, the only things on the load side of the fuse are the horn and the dome lights. The ignition switch and starter are not fused and are on the line side of the fuse. A short in the ignition switch would not blow the fuse as the current to the switch does not flow through the fuse block. A fuse blows because too much amperage is flowing through it and, in your case, the only things that draw from that fuse are the horn and dome lights.

Please check your wiring at the fuse block and report back.

The horn and dome light are always hot - why would the fuse only blow when the key is turned?

You're right, it shouldn't matter if the ignition is turned on unless the wiring has been modified--that's the point I wanted to make. Didn't seem to come out clearly.