As Higgins would have said: "My God, Magnum! Your FIRST car project, and you've hit a wall on the easiest repair!" I'm planning to start a full restoration thread this week, but wanted to get my individual technical questions out of the way first. First task easing into mechanically restoring my 79 GTS is installing a Birdman fusebox. I'm willing to accept the gospel that it cures electrical problems, and is a simple solution to the "flawed" OEM design. That said, I found no apparent problems with my blocks, and they appeared made of nylon, not like the examples with meltable bus bar mountings on Birdman's site (Pics 1&2). At any rate, several connectors that fit snugly and "all the way" onto the OEM prongs will only slide about 1/3 to 1/2 way onto the Birdman connectors (see Pic 3), and only with great enough force that I'm afraid of breaking something. At the risk of sounding amateurish - but since I don't usually do electrical work - here are my questions: 1) How does one "clean" these connections? I bought contact cleaner spray, but don't really see corrosion on the leads inside the plastic connectors. Not sure about neatly spraying cleaner into those plastic bits, or how I'd scrub the leads anyway without removing the connectors. 2) Is it recommended/okay to use dielectric grease to help the plastic connectors slide onto the prongs and splitters? 3) Is it difficult/advisable to just pull off the connectors and re-do the wire leads in the name of fuller restoration? Are the plastic connectors easily sourced? I ask because, as you can see in Pic 4, a couple of my wires have been taped up and look like they've seen better days. The connectors are stuck on there pretty good, and I don't want to damage something I can't fix. 4) Many forumers have discussed removing previous owners' electrical add-ons, or "unnecessary items." I can clearly read the OEM covers to see each fuse function, but how do you know what's extraneous, especially when some fuses have split connectors and only one listed function for that slot? Besides a radio and A/C, I don't think my car has any electrical extras. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
I haven't seen that issue before, I would expect that if you wiggle them a little they should go on just fine. Take a look in the end of the connector and see if the little tabs are squished. They shouldn't need cleaning. No. If there are any that are particularly damaged, go right ahead and lop the connector off and crimp on a fresh one. I'm not sure if you can recycle the plastic tab that covers the connector or not. Any connectors that are not damaged, there is no point in changing them. Add-ons are easy to spot because they will not use the same plastic tab as the stock wiring harness. Also, you can look in the schematic and see how many wires should be on each tab and what their color-code is. So even if someone has replaced a connector with a new one, you can determine if that circuit should be present. Most "add-ons" are audio related (power amp for example) or for a alarm or radar detector. There is no harm in having additional electrical stuff in the car as long as you know what it is and where the circuits go. As far as schematics go, I can't recommend these color-coded schematics from Paul Bennet enough. Wiring Diagrams 308 365 400i 512 Birdman
Birdman's blocks are great, but if you want to keep the OEM appearance and if your OEM fuse block are not melted they can be soldered to insure good contact and the fuses replaced with new ones. [edit] Before I soldered these if I touched the fuel pump connection it would burn my finger. Afterwards, it would get slightly warm, but not hot, not uncomfortable to touch. Image Unavailable, Please Login Image Unavailable, Please Login
Thanks everyone. Would anyone worry about that fourth wire that's all taped up, or just leave it alone?
A vintage Mercedes owner told me about a new line of ceramic style fuses being sold by MB. Apparently they're much improved over the old ones.
Good day Johnk, This is what I did and maintained the OEM look and fuse covers. That being said, indeed, soldering the connections will help a lot to address some of the Original fuse block issues. Sadly, the "clips" become fatiqued over time resulting in less clamping force against the original style fuses... which causes oxidation ... a great voltage drop ... and thus more heat and less voltage for the load. Cheers, Sam Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Nice. But I did not find the clamping pressure to be weak. Rather what I found was that over time the clamps had actually cut through the copper "hats" on the ends of the ceramic fuses resulting is reduces contact area and consequently another source of higher resistance and current loss. Another interesting benefit was that, while I never had over heating problems with my car (85 QV) I had noticed that operation temps were increasing beyond what they were when new. After soldering the fuse holders and replacing the fuses temps dropped back downs as the fans ran noticeable faster.
Hi, where can you get those fuse boxes shown in Sam's posting ? Are those custom made...?? Kind Regards, Joachim
Good day Patrick, My apologies! ... That being said, I have been slowly gathering all the bits and pieces to make more of them... so the tease could also be interpreted as a shameless plug Cheers, Sam
Good day Joachim, Yes, these are custom made by me. I detailed the design and analysis in the Boxer section (search Boxer Fuseblocks). Incidentally the fuse blocks are virtually all the same for the 308 (GT4, GTB/S injected or carb) and Boxer (injected or carb) series. The only differences are the fuse sizes and that the injected cars have a slightly different common power connection for a few fuses on the white blocks. Cheers, Sam
Good day John, Indeed, this can happen too. However the clips themselves will fatigue over time which reduces the clamping pressure etc. If one periodically cleans the contacts/fuse ends and lightly pinches the clips together, this will somewhat alleviate this issue. In my case my blocks were simply too knackered to repair, but also I just found it frustrating to have to worry about the OEM fuse blocks... and thus I tried to improve the overall design while maintaining the OEM look and fuse covers. The added benefit was that by using ATC fuses meant that I could go pretty much anywhere and find replacement fuses if needed. Cheers, Sam
