fuse box confusion

[gdp_samson]

Hi,

in preparation to ever install a mini blade fuse box like Classic Retrofit or Adapt, I thought to dive into the fuse box a first time (1988 3.2 hasn't had electrical issues since I bought her several years ago...).

After some reading and the Joe Engineer video about his ADAPT fuse box installation

I was ready to find a similar fuse box with 21 connections

3 - 10 - 8

but that was not the case...I had like intermediate connections without a fuse ?
so I counted more than 21 ...



Anyone has an idea what this is ?

I also found some wires connected at the bottom without a fuse...and on the other hand, did not find the headlight relays although this US car had been modified to EU specs 15 years ago apparently...

[gdp_samson]

[PeteKz]

Every once in awhile I think about upgrading my 1973 fuse blocks to the Classic Retrofit or Adapt ones, and then I think about the warning, "if it ain't broke, don't fix it!" You could end up causing yourself more trouble than you avoid. Those bullet fuses are a crappy design, but if you just change them every 10 years or sooner, you won't have many fuse problems. Much easier and cheaper and less likely to break something that isn't broken.

Now, if yer doing a whole electrical rewiring project anyway, then yeah, I'd put in the blade fuse blocks.

[HarryD]

Originally Posted by gdp_samson

Hi,

in preparation to ever install a mini blade fuse box like Classic Retrofit or Adapt, I thought to dive into the fuse box a first time (1988 3.2 hasn't had electrical issues since I bought her several years ago...).

After some reading and the Joe Engineer video about his ADAPT fuse box installation

I was ready to find a similar fuse box with 21 connections

3 - 10 - 8

but that was not the case...I had like intermediate connections without a fuse ?
so I counted more than 21 ...



Anyone has an idea what this is ?

I also found some wires connected at the bottom without a fuse...and on the other hand, did not find the headlight relays although this US car had been modified to EU specs 15 years ago apparently...

[warning]If you do not take the time to understand German wiring philosophy, please step away from the fuse box [/warning]

Get a factory wiring diagram. It will identify which fuses are jumper together under the fuse box. This will explain all.

[GH85Carrera]

Originally Posted by HarryD

[warning]If you do not take the time to understand German wiring philosophy, please step away from the fuse box [/warning]

Get a factory wiring diagram. It will identify which fuses are jumper together under the fuse box. This will explain all.

Read that again, and print it out.

The fuse box in our 911s is just not like American cars. Just be careful.

[gdp_samson]

I have a wiring diagram, but none include the changes that some previous owner(s) made...

I just wanted to know if it was rather 'common' to see added screws / connections on the top of the fuse box row...

On the other hand: indeed, nothing seems broken now, so maybe better to step away from this

[Dpmulvan]

Originally Posted by gdp_samson

I have a wiring diagram, but none include the changes that some previous owner(s) made...

I just wanted to know if it was rather 'common' to see added screws / connections on the top of the fuse box row...

On the other hand: indeed, nothing seems broken now, so maybe better to step away from this

Blade fuse sockets are like a $1 a piece, I’m going to see if I can come up with a way to just replace the fuses and use the factory board. Like the others said if it’s not broke don’t fix it.

[darrin]

Originally Posted by gdp_samson

I have a wiring diagram, but none include the changes that some previous owner(s) made...

I just wanted to know if it was rather 'common' to see added screws / connections on the top of the fuse box row...

On the other hand: indeed, nothing seems broken now, so maybe better to step away from this

Believe the added connections you're seeing come from the factory that way (they're bridged behind the panel) -- my '86 targa has the same ones shown in your picture. I'm in agreement with others' sentiment on this issue, "if it ain't broke . . " I proactively replaced all of my bullet fuses a few years ago and cleaned the connectors up with a wire brush to remove oxidation at their contact points -- fusebox still behaving like a champ.

OTOH, If your car doesn't have a headlight relay installed, I'd strongly recommend tackling this project asap (before you start having issues with your high beam switch)

[porschedude996]

I thought about updating the fuse blocks. Over the years with several different 911’s with bullet fuses, I have not had many problems. On my new project, 1983 911SC, I changed out the ceramic fuses with torpedo glass fuses. They seem to me a bit better with regard to corrosion. Bussmann GBC’s. I found them on ebay.

[Jonny H]

Originally Posted by gdp_samson

Hi,

in preparation to ever install a mini blade fuse box like Classic Retrofit or Adapt, I thought to dive into the fuse box a first time (1988 3.2 hasn't had electrical issues since I bought her several years ago...).

After some reading and the Joe Engineer video about his ADAPT fuse box installation

I was ready to find a similar fuse box with 21 connections

3 - 10 - 8

but that was not the case...I had like intermediate connections without a fuse ?
so I counted more than 21 ...



Anyone has an idea what this is ?

I also found some wires connected at the bottom without a fuse...and on the other hand, did not find the headlight relays although this US car had been modified to EU specs 15 years ago apparently...

There is a bit about the 'intermediate' fuses on page 7 of our install manual here:

https://www.classicretrofit.com/pages/manuals-and-software

(p.s. You won't find headlamp relays on any standard air cooled 911 - that's why we add them to our panel)

[PeteKz]

Originally Posted by porschedude996

I thought about updating the fuse blocks. Over the years with several different 911’s with bullet fuses, I have not had many problems. On my new project, 1983 911SC, I changed out the ceramic fuses with torpedo glass fuses. They seem to me a bit better with regard to corrosion. Bussmann GBC’s. I found them on ebay.

Thumbs up on those too.

[darrin]

Originally Posted by PeteKz

Thumbs up on those too.

I went with the stainless torpedo fuses a few years ago as well. At the time, folks expressed concern that the stainless fuses might react with the brass terminals. I've kept a close eye on this and so far, no problems at all.

[gdp_samson]

Originally Posted by Dpmulvan

Blade fuse sockets are like a $1 a piece, I’m going to see if I can come up with a way to just replace the fuses and use the factory board. Like the others said if it’s not broke don’t fix it.

I think many are very interested to go that way...I'll be watching you

[gdp_samson]

Originally Posted by porschedude996

I thought about updating the fuse blocks. Over the years with several different 911’s with bullet fuses, I have not had many problems. On my new project, 1983 911SC, I changed out the ceramic fuses with torpedo glass fuses. They seem to me a bit better with regard to corrosion. Bussmann GBC’s. I found them on ebay.

these are a simple replacement ? they fit in the same area without any change whatsoever ?

[gdp_samson]

Originally Posted by Jonny H

There is a bit about the 'intermediate' fuses on page 7 of our install manual here:

https://www.classicretrofit.com/pages/manuals-and-software

(p.s. You won't find headlamp relays on any standard air cooled 911 - that's why we add them to our panel)

good point, don't have headlight relay and could buy one (85 EUR) but then again, this is integrated in your fuse box (so that would not cost me 340 EUR then, but 340 minus the 85)... at least, that's the argument I'm gonna use towards my wife

[HarryD]

Originally Posted by gdp_samson

good point, don't have headlight relay and could buy one (85 EUR) but then again, this is integrated in your fuse box (so that would not cost me 340 EUR then, but 340 minus the 85)... at least, that's the argument I'm gonna use towards my wife

Are you referring to the factory headlight relay or the aftermarket one to isolate the flasher stalk from the headlight current?

[gdp_samson]

https://www.kroonwireharnesses.com/porsche-911/porsche-911-1988/headlight-relay-set-for-porsche-911-74-88-version?sort=p.price&order=ASC

[HarryD]

Originally Posted by gdp_samson

https://www.kroonwireharnesses.com/porsche-911/porsche-911-1988/headlight-relay-set-for-porsche-911-74-88-version?sort=p.price&order=ASC

Ok.

Our host May be less expensive. https://www.pelicanparts.com/More_Info/JWST911HLPR.htm?pn=JWST-911-HLPR&bc=c&SVSVSI=0577

[gdp_samson]

Originally Posted by HarryD

Ok.

Our host May be less expensive. https://www.pelicanparts.com/More_Info/JWST911HLPR.htm?pn=JWST-911-HLPR&bc=c&SVSVSI=0577

the shipping to and import taxes in Belgium will make it horribly expensive I'm afraid...time to launch a PelicanParts Europe

[HarryD]

Originally Posted by gdp_samson

the shipping to and import taxes in Belgium will make it horribly expensive I'm afraid...time to launch a PelicanParts Europe

Ok. Makes sense.