Reverse-mount 12V alternator

Dedicated to the memory and knowledge shared by Jim Mettler - All things relating to the flow of electrons in a Pinz.
Sonarman
United States of America
Posts: 78
Joined: Sun Feb 05, 2017 8:15 pm
Location: Sonoma, Ca

Re: Reverse-mount 12V alternator

Post by Sonarman » Sat Sep 07, 2019 8:12 pm

Are you going to sell the bracket?

Thanks

Texas710
United States of America
Posts: 183
Joined: Thu Jan 22, 2015 4:00 pm
Location: San Antonio, TX

Re: Reverse-mount 12V alternator

Post by Texas710 » Mon Sep 09, 2019 9:39 am

Great job, I am sure a lot of people would be interested in purchasing one of these. I will be interested to see how it wears over time, but looking great

kdiqq
United States of America
Posts: 270
Joined: Tue May 26, 2015 3:30 pm
Location: Houston, TX

Re: Reverse-mount 12V alternator

Post by kdiqq » Mon Sep 09, 2019 8:27 pm

Personally, probably not going to sell it. I have a ton of other projects going on right now and I'm not sure I could offer the support a product deserves.

That being said, I will likely license the product to be supported by another Pinz owner. Stay tuned for that. That should allow me enough time to shake the thing down and see if I run in to any reliability problems.
1977 Austrian 710M

Bumber
Posts: 24
Joined: Sun Aug 10, 2014 9:36 am

Re: Reverse-mount 12V alternator

Post by Bumber » Tue Oct 15, 2019 1:24 pm

I haven't been on this forum in ages, so please forgive me if this has been covered ...

While running a second system you will find that one of your batteries is dragged down and beat unconscious. This, as I personally found, is due to the fact that everyone makes all their doodads and thingies to have a grounded frame. For example, my Warn 12V winch (running on 24V makes them much better) is running off a second set of Odyssey batteries placed in the second toolbox. One of the batteries went bad. After a lot of testing I found that the problem was that the winch is grounded, which was bolted to the winch mount, which was bolted to the truck. Even though there was a separate ground wire on the winch, the frame of the winch was grounding out. The solution was non-metallic washers and a sleeve over the shaft of the bolt to prevent the winch from grounding. I had a similar issue with my fog/spot lights. I had to use non-metallic washers and rubber grommets to isolate them from the light bar and prevent grounding. Once these isolation steps were taken, the battery levels remained constant. As best I can tell the ground was sneaking a little bit of electrons around the system to the factory batteries and giving them preference. In addition to all the isolation, I had a custom switch made that isolates the second set of batteries if the main batteries fall below 12.2V each (24.4V total) to prevent any ground leak from ever placing havoc with the main batteries. It works quite well, although I designed the switch slightly small. I put a lower amperage fuse in it and after using the winch for about 15 minutes to pull a friend's bushes out of the ground, the spare batteries get low and draw too much power from the alternator and the fuse pops. My solution was to hang a pack of fuses inside the box. But a better solution would have been to design the next switch with a 40 amp fuse. :)

kdiqq
United States of America
Posts: 270
Joined: Tue May 26, 2015 3:30 pm
Location: Houston, TX

Re: Reverse-mount 12V alternator

Post by kdiqq » Wed Apr 08, 2020 8:07 am

So I've gotten a ton of inquiries about this bracket. First off, I had no issues with it at all. Truck doesn't seem to notice at all, starts and drives the same. I used a marine battery box from Summit to mount a 12V battery and kept the ground common to the 24V system. I'm not saying this is how it has to be done, if you want to keep the ground separate, you can space the alternator with phenolic washers and have two isolated systems. Really, it's up to you, but my electrical eng said it wasn't needed, so I didn't do it.

In related news, I no longer have the truck. I moved on to another project and making space for some other things. Will probably get another Pinz or C303 sometime in the future!

So, I'd like to turn this project over to the community. Here are my design files. The BOM I listed on a previous page still applies, just add a belt of your choice. You can send it to your favorite sheet metal manufacturer as it is or modify it, sell it, frame it, whatever you want. I hope y'all can find a way to make it even better!



https://drive.google.com/drive/folders/ ... sp=sharing
1977 Austrian 710M

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