Cranetruck did a write up in MV mag. years a go, someone did a thread on this subject not long a go, CT added his data to it, very good and informative, look up protective control box or something like that in search.( about 25 threads with a lot of input from CT )
Last Thur, Tim and I talked about a bypass for the box ( getting ride of it all together) should be easy to do with a few off the shelf parts, this sure would make 5t life a lot easier
I would say look up these threads. They prob will explain it better than I could.
Ya yours looks like it has somemore electronics, and does not have the small coil. Is yours a Prestolite? and what year do you think it is?
Southern Automotive is the label on the box. It was new in '06 when the 818 was rebuilt. Had trouble with an intermittant loss of electrical power and the box was the culprit. Not sure why. Took it apart and tested the relays. They were fine. Replaced it with a new box and has worked fine ever since.
I gave several dead boxes to a buddy a month ago in order to have him rebuild/upgrade the components in them. He works on military electrical systems for a living and thinks that he can offer a very competative refurb business but wanted to play with a few first.
A 900 box will work with a 800 series truck, but not the other way around.
The article in MV magazine and the other threads on here have some really good info on them.
I try to always have a couple around as spares...
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Convoy Commander, 2012 East Coast Convoy
'53 M37 with Cummins 4BT, '63 XM708 dump
'68 M274A5,
'51 and '52 M38,
'70 XM813, '71M817 dump, '70M816
