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Ford/NH 555D issue

eKretz

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Nov 29, 2023
Messages
80
Location
NW Indiana
Very interesting indeed! Did you find any potentially faulty components? One of the relays maybe getting weak?

Not yet, still digging down to get to all the component leads. I try to identify every component first when doing this, as it's highly likely that I'll damage some of them digging down to remove the potting compound. To get to the relay pins I'm going to need to get the circuit board completely out. Still digging but I might not get it all the way done tonight.

So far I've inventoried the 2 relays, 2 capacitors, 3 FETs, 3 variable resistors, a zener diode and a plain Jane resistor.
 
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eKretz

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Nov 29, 2023
Messages
80
Location
NW Indiana
And, as I feared, the back side is WAY more complex:

20231210_223411.jpg

I'll check the relays individually, as well as look at all the solder joints and check for cracks. I'll also check the two electrolytic caps for high ESR - they can sometimes cause all sorts of trouble as they age. I broke diode D5 and slightly melted the variable resistors on the opposite side while removing potting compound, will have to order those and replace them.
 
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eKretz

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Nov 29, 2023
Messages
80
Location
NW Indiana
New development. I've got an idea for a replacement setup that is actually available to buy today, and not very expensive. It will basically replace this entire module. I'll try out the idea and report back.
 

eKretz

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Nov 29, 2023
Messages
80
Location
NW Indiana
Victory! Just ran the machine for a couple hours with zero issues. Pulled a couple stumps, then hauled off the wood and graded back over with the loader bucket. Not a hiccup the whole time. I only had this set up in a temporary fashion at the moment to see if it would work. I happened to have a PWM DC motor controller with programmable soft start laying around the electronics bench. This particular model soft starts as soon as it powers on. Perfect for use with the signal from the shuttle shift stalk. Also can be set to display either voltage or amperage in use. Also nice.

I took the plugs from the original controller so it could plug straight into the harness. I set it up with a ganged ground to both solenoids, and the positive from the controller going to a 3-position toggle switch. That way I could set the toggle switch for sending power to either the forward or reverse solenoid, then engage the shuttle shift to forward to activate the solenoid and engage the selected clutch. I settled at a 2.5s soft start engagement time, that worked pretty good. I just ordered another controller, so in the permanent installation I'll have one controller for forward and one for reverse, that way the toggle switch will be eliminated and the shuttle will work just like it originally did. These will tuck up under the dash just like the original. They're rated for way more power than is needed in this application, so I'm hoping they'll be pretty hardy.

Speaking of which, the original control module is unavailable anywhere as far as I can tell. These DC motor controllers are available on eBay for around $25-$30 each. I'll probably order some spares.

20231211_135720.jpg
 
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Welder Dave

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Oct 11, 2014
Messages
12,517
Location
Canada
This is one of those times you're specific knowledge with something really paid off. I'd have been totally lost. Congrats on getting it working.
 

eKretz

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Joined
Nov 29, 2023
Messages
80
Location
NW Indiana
This is one of those times you're specific knowledge with something really paid off. I'd have been totally lost. Congrats on getting it working.

Thanks. I am told that I'm pretty good at fixing things. People call me all the time for help, heh. Have always had a knack for it. I wasn't particularly looking forward to spending several hours on digging through the original board without a schematic, so it was a happy circumstance that I thought of using the motor controller.
 

Welder Dave

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Oct 11, 2014
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12,517
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Now you just have to get it to read the proper speed you're going or RPM. A problem like you had would have a huge majority of people pulling their hair out trying to figure out what's wrong and how to fix it.
 

eKretz

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Nov 29, 2023
Messages
80
Location
NW Indiana
It already has a separate tach that still works just fine. Never had a speedo. And yeah, I have saved more than a few things that would otherwise have been in the dumpster or a rusting hulk somewhere... I'm not a fan of disposable stuff. I would rather rebuild or repair, modify if necessary. Hopefully this will help some other owners who might run into the same issue some day.

Next on the list for this machine after the new controllers are installed is an adapter for a front quick change. I'd like to be able to use a set of forks (and still see where they are!) and a couple other things. May make and weld up my own. I'm leaning toward the Global/Euro.
 

eKretz

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Joined
Nov 29, 2023
Messages
80
Location
NW Indiana
Ah, gotcha. I'll probably leave those hidden away up under the dash. Useful for troubleshooting though, they display the amperage that the solenoid coils are pulling.
 

rumblecloud

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May 6, 2012
Messages
187
Location
Michigan
Occupation
Living the dream...:]
Now you just have to get it to read the proper speed you're going or RPM. A problem like you had would have a huge majority of people pulling their hair out trying to figure out what's wrong and how to fix it.
Unfortunately I don't have enough hair to pull out...but you are right on in your assessment --- I didn't understand a thing that he said :D
 

eKretz

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Joined
Nov 29, 2023
Messages
80
Location
NW Indiana
If any future readers should need help setting this up, just send a PM, more than happy to help. The nice thing about this setup is that if an original module *is* ever found, it can still be plugged right in and used too. All the modifications made to wiring are on the module side of the plug, the tractor side is still all original.
 

eKretz

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Joined
Nov 29, 2023
Messages
80
Location
NW Indiana
Ack. My order of DC motor controllers got screwed up and instead they sent me AC fan speed controllers. Working on getting them swapped now. Latest project: cleaning up the rims and getting them ready for new front tires. Sandblasted them outside behind the garage, and then a couple primer coats, then a couple of Raptor bed liner paint. Should outlast me hopefully.

20231222_041156.jpg
 

eKretz

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Joined
Nov 29, 2023
Messages
80
Location
NW Indiana
Here's my near final implementation of the FWD/REV controllers. Including a shot of the harness terminals and my extended harness. The original red wire is not used, so it can just be capped or taped off. I only have mounting the controllers up under the dash left to do.

I made up the small extension harness earlier tonight and tested the controllers, everything is working perfectly via shuttle switch. I used the same color wires on my harness that the original harness uses. I'll include a photo of the wired connections. I just ran a jumper across from "Power -" on one controller and connected it to the same terminal on the other with a black wire. For the overload setting, I set it at 3.0 amps, and I think I'm settled on a 3.0 second soft start. I left the under-voltage protection setting at 10.0 V. I left my displays set for amperage so I can monitor the current the solenoid coils are pulling. Oh, and the "soft stop" timer I set to 0.2 second so that it's almost instant off.

20240104_182156.jpg

20240104_183529.jpg
 
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