mcarlson93

I searched the forum with no luck but...

The previous owner of my 928 had all the fuses replaced with buss type fuses, I know the car isn't supposed to have that type of fuse but I have a very limited knowledge of electrical systems. My question is has anyone else done this with their car (or heard of it being done) and could it cause any issues with the electrical system? I'm assuming the new buss fuses are the same amp as the ones they replaced but obviously the car wasn't designed for those and I'm having issues with headlights not working and turn signals not working, could these new fuses have something to do with that?

dr bob

What year?

mcarlson93

It's a 79

Alan

What do you mean exactly - ATO/ATC style fuses and fuse holders?

Can you post a picture of what you have now so we can see what was done...?

The old style fuses are generally a little bit more problematic than the later ATO/ATC style used in 928's 1985 and later. However regular cleaning every few years was all they really needed to stay in good shape.

Depending on how well this was done it may be a good improvement.

Alan

mcarlson93

No they're not ato/atc fuses or fuse holders, they're buss type fuses (not sure if that's the technical term but the maintenance history says "replaced old fuses with buss type fuses") I can't post pictures to the forum for some reason but if you google it you'll see what I'm talking about, they're a glass cylinder with metal caps on each end and the metal strip in the middle of the glass. All that was done was they took the old fuses out and put that style in, no modifications to the holders. The fuse panel is the same as it would be if it had the original fuses in it.

Alan

Well that would be a bad choice then - these have flat ends which won't stay located in the holders very well.

Get replacement OE style ceramic barrel fuses from a reputable supplier, and clean all the fuseholders before you install them.

Alan

mcarlson93

Thank you for the help! I was planning on doing just that but I've never seen one of those ceramic fuses in my life so I wasn't sure if these new fuses were an improvement or not. You're right though, they don't stay in there very well at all. switching them out asap!

dr bob

Buss makes a glass tube fuse with pointed ends. It's their standard replacement for the ceramic/plastic fuses. The original way-back-when German fuses had bare copper elements. Those upgraded to tin-plated elements at some point in the mid 1960's because of oxidation issues. The fingers in the holders were changed at some similar point. The Buss replacements with flash-chromed ends and sealed elements were considered by many to be an upgrade from the tin-plated since they were mechanically more stable.

Alan

If you mean the GBC fuses I believe the dimensions are slightly off (smaller) Probably not a big issue if you tension all the fuseholders for a sure grip.

Bosch ATS Torpedo type: 25mm length ~5-6mm 'diameter' (not round)

Buss GBC Glass type: 24.6mm length ~6.4mm diameter

Whilst an encapsulated fuse element seems desirable - the fuse end contacts are really the problematic area with these type of fuses. Lower tension from a shorter body would likely make these worse unless you also adjust the holder terminal tension, I'd suggest that is smart to do anyway in ~ annual maintenance even for the Bosch ATS fuses.

Alan

Landseer

The Bus style round fuses have length variation, as Alan says.
We've proven that here before with micrometer measurements.
They are typically too long for the fuseblocks and over stretch the electrodes.
Overall, they then don't fit well.
Can't spin them to seat them, the wimpy electrode bends in the middle and/or tear on the ends.
see post 25, especially the associated picture of the fits within the fuse blocks.
Great start, replace with the right ones. Get that fusebox solid, makes chasing the rest easir.

Look familiar?

https://rennlist.com/forums/928-foru...t-blowing.html