Help for a new m936 owner please...

[nayrbrellim]

Bad pcb. Smack it with a hammer if you need it to work.

Rebuild it afterwards.

It's the black box behind the washer bottle on the drivers side of the engine bay.

Pcbs go on the fritz during hot and cold snaps in weather generally

Fuel vents won't cause any issue like you had. Especially broken

Where in TN are you?

I actuallty had my PCB go bad, incredibly enough hitting it with a hammer works, well for a little while.

 

[The FLU farm]

Alright, resurrecting an oldie here as I'm not sure what's the least dumb thing to do next.

M936 A1 with ABS (or at least the sticker) that one day had a completely unresponsive dash when turning that battery switch on. It clicks under the hood, lights work, etc., but dead dash.

Bonked the box somewhat lightly with a small hammer, resulting in that the the warning lights lit up, the shrieker made a muted noise, the fuel gauge woke up, and the volt meter moved up a needle width or two.

Removed the box and activated the solenoids with a small 12 volt battery. The bottom one sounded perfect, the top one a bit lame. Cleaned the corrosion off the easily accessible posts, plugged the box back in...back to nothing (could have been a bad ground to the box).

So here are my questions after watching Simp's videos: Do I need the electronics on the board in this application?

Do I need the second solenoid? I don't need functioning ABS.

Could I simply wire in a single 24063 solenoid and mount it outside the box, or maybe even leave the box off altogether?

Any words of wisdom will be appreciated as I need to move this one to access a trailer.

 

[IronGiant5Ton]

Alright, resurrecting an oldie here as I'm not sure what's the least dumb thing to do next.

M936 A1 with ABS (or at least the sticker) that one day had a completely unresponsive dash when turning that battery switch on. It clicks under the hood, lights work, etc., but dead dash.

Bonked the box somewhat lightly with a small hammer, resulting in that the the warning lights lit up, the shrieker made a muted noise, the fuel gauge woke up, and the volt meter moved up a needle width or two.

Removed the box and activated the solenoids with a small 12 volt battery. The bottom one sounded perfect, the top one a bit lame. Cleaned the corrosion off the easily accessible posts, plugged the box back in...back to nothing (could have been a bad ground to the box).

So here are my questions after watching Simp's videos: Do I need the electronics on the board in this application?

Do I need the second solenoid? I don't need functioning ABS.

Could I simply wire in a single 24063 solenoid and mount it outside the box, or maybe even leave the box off altogether?

Any words of wisdom will be appreciated as I need to move this one to access a trailer.

View attachment 937300View attachment 937301

FLU Farm, I just had this exact issue happen to my truck. My box circuit board shit the bed. I tested the old solenoids and they ready 55ohms on ne, 25 ohms on the other. Correct for continuous and intermittent solenoids.

In short, I'd wire 2 solenoids in the box even if not using ABS to prevent further issues down the road. I used 2 Cole hersee 24063 solenoids and the original box. No diodes inbetween.

If you need to start it just to move it temporarily you can jump "D" and "C" in the wiring harness, disconnect the electrical line on the same side as that box that goes to the fuel cutoss solenoid and touch negative and positive on the starters solenoid. You just won't have gages.

My circuit board looked like a resistor and a diode got way too hot and fried out.

I just got it rewired and started it up today no problem.

 

[The FLU farm]

Thanks! I ended up doing the very same thing (in here waiting for the liquid electrical tape on the new wiring to dry) hoping it'd work. Now I'm confident it will.

One thing I did differently was to modify the box a bit. basically cut the end of the lid where the connector goes off of the box and welded it to the base. That way the lid can be removed without disturbing the connection, should a 24063 stop working. Also haven't looped the yellow wire like you did. Should I, and if so why?

When testing the OE solenoids the top one had a much fainter "click", and no continuity. Anyway, I'll post some photos when the new paint on the box has dried.

 

[IronGiant5Ton]

Thanks! I ended up doing the very same thing (in here waiting for the liquid electrical tape on the new wiring to dry) hoping it'd work. Now I'm confident it will.

One thing I did differently was to modify the box a bit. basically cut the end of the lid where the connector goes off of the box and welded it to the base. That way the lid can be removed without disturbing the connection, should a 24063 stop working. Also haven't looped the yellow wire like you did. Should I, and if so why?

When testing the OE solenoids the top one had a much fainter "click", and no continuity. Anyway, I'll post some photos when the new paint on the box has dried.

I looked the yellow wire because its a sensing line from the alternator. I have a Brushless aftermarket alternator which is wired in differently from the OEM. therefore, kinda useless.

 

[The FLU farm]

Put the lid and base on top of the furnace for tonight, to hopefully cure the paint quicker. As you can see, I didn't spend any time making it look good, but it should work.

Drainage holes by the connector small enough to keep insects out, but should be enough to vent the interior and avoid the corrosion that was present in the OE box.

Had the same ares blackened on my circuit board, by the way.