Protective control box signals

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snock
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Protective control box signals

Post by snock » Wed Sep 30, 2015 8:46 am

Does anyone know idea behind running the parking brake switch signal into the PCB on the control box? The only thing I can see that being good for is to be able to control the "BRAKE" light provided the brake is released. My green label KDS would make the brake light flicker when started but I just assumed this was a bug. Also, I am assuming that the AC output of the alternator is run into the unit to give it a signal that the engine is running. Does that sound right?

I'm thinking of building up some replacement PCBs for these units since it looks to be a PITA to find them in known good working order and they seem to be the source of many headaches with these vehicles.
1989 M998
1964 M151 w/1967 M416
1986 M1009


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Kurt Lesser
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Re: Protective control box signals

Post by Kurt Lesser » Sat Oct 03, 2015 6:54 pm

The Brake warning light goes into the PCB on the body connector pin C and then in to the lamp check relay. This should activate when the truck is initially powered on.

Making up replacement circuit boards for the PCBs is going to entail an awful lot of work. Just take the dead one and replace the toasted MOSFET with a better one.

Kurt
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US Navy, 1969-1975
M996A1 Ambulance w/M101A3 Trailer
M274A2 Mule
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snock
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Re: Protective control box signals

Post by snock » Mon Oct 05, 2015 12:06 pm

I guess the lamp check function makes sense though I never noticed it since my truck always had the brake applied when starting. I really wish it was just blown MOSFETs but they're good. Tonight I am going to connect up a 9V battery and pushbutton switch to drive the gates on the MOSFETs so I can get this thing started. I've put a couple hours into troubleshooting the PCB and I'm already sick of looking at it. It should be fairly trivial to build up a replacement PCB that acts like the green label open loop KDS units. I get bored in the winter anyways.
1989 M998
1964 M151 w/1967 M416
1986 M1009

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Kurt Lesser
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Re: Protective control box signals

Post by Kurt Lesser » Wed Oct 07, 2015 10:09 am

I'm still looking forward to the days when I can get bored! I tried contacting Nartron without much success to see if we can get a schematic of the PCB. I'm wondering of there's a patent application on it that would be public information.

My box is still working so I'm not inclined to open it up but would like to pick up a dead one. Somebody must have one that's fried out there.

Kurt
Kurt Lesser
US Navy, 1969-1975
M996A1 Ambulance w/M101A3 Trailer
M274A2 Mule
M151A1 Mutt w/M416B1 Trailer
M890 Crew cab

snock
G-Sergeant First Class
G-Sergeant First Class
Posts: 77
Joined: Fri Jul 30, 2010 9:11 pm
Location: Loudonville, Ohio

Re: Protective control box signals

Post by snock » Wed Oct 07, 2015 12:10 pm

beltfed34 has some yellow and white label boxes on ebay and they are likely dead. I should have one arriving today or tomorrow. Hopefully the PCB mounting studs are in the same location for the green, white, and yellow label units. It seems there would be more of these out there but used automotive electrical parts are always problematic. A friend has a green label unit in his that I managed to fix once so it's a cross your fingers kind of part which is why I want to build up some replacement PCBs. Then I could buy up the dead units and use them as cores for rebuild. I'm just not willing to drop close to $800 on an S3 box and any of the KDS, Nartron, etc. boxes on govliquidation have to be suspect.
1989 M998
1964 M151 w/1967 M416
1986 M1009

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Kurt Lesser
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Re: Protective control box signals

Post by Kurt Lesser » Thu Oct 08, 2015 3:41 pm

Where are you located? It really should be a part of your profile. Maybe we could work together on this project.

Kurt
KG6KMJ
Kurt Lesser
US Navy, 1969-1975
M996A1 Ambulance w/M101A3 Trailer
M274A2 Mule
M151A1 Mutt w/M416B1 Trailer
M890 Crew cab

snock
G-Sergeant First Class
G-Sergeant First Class
Posts: 77
Joined: Fri Jul 30, 2010 9:11 pm
Location: Loudonville, Ohio

Re: Protective control box signals

Post by snock » Fri Oct 16, 2015 5:32 am

I'm in Ohio. I've got something in the works now with a 14 pin PIC and high side driver IC. I don't plan on using the temp. sensors. It will work like the KDS green label time based units but I'm guessing the PCB will look a little less crowded due to the use of the high side driver IC.
1989 M998
1964 M151 w/1967 M416
1986 M1009


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