M1083 Voltage drop and intermittent start issues found

[Grimbo]

Been seeing a voltage drop between the batteries(fully charged and good batt connections) and the cab voltmeter, starter was also intermittent and eventually no start. Problem came down to a cooked/corroded starter motor solenoid, and the 12v/24v isolator/diode bank was blown out(looks like corrosion). Also bad ground to alternator so redid that and put new bearings in alternator while it was off. Does anyone know where to get a new diode/isolator bank - 55156-2111B If I cant find one I will most likely install a separate 12v and 24v units. pics https://photos.app.goo.gl/kgMnewQoW92dtuie9

 

[GeneralDisorder]

Wow. Such a mess.

You can delete the polarity protection device if you don't believe you are silly enough to connect the batteries incorrectly like PVT Snuffy.

GD

 

[Third From Texas]

Wow. Such a mess.

You can delete the polarity protection device if you don't believe you are silly enough to connect the batteries incorrectly like PVT Snuffy.

GD

Guy on FB with an A1R just did this very thing (hooked up the batteries backwards).

Now he has Christmas lights for a dashboard (not strobing in sequence, but just all flashing at once) ...and a bricked truck it seems.

 

[Ronmar]

You really should have a diode on the 12v feed to the power panel. If the battery ground path is disconnected, battery power from the 12-24 battery can possibly flow thru a 24V circuit to chassis ground and backward thru a 12V device to reach the - terminal of the 12-24v battery and complete a backwards current path. Now there are not too many 12V devices native on an LMTV, but the trans on the A0 does receive 12V via the VIM and I have no idea if it has internal diode protection… Any added 12V devices could also be at risk, as soon as the main battery ground lead is disconnected. The polarity protection device provides this protection…

 

[Grimbo]

I found a ProMariner 2-130-2 that is dual alternator dual output multi voltage, when it arrives ill check that the two alt inputs aren't somehow cross connected and that should do it. I like the idea of deleting it as GD mentions, but I think of anyone else touching it when I'm not there

 

[wheelspinner]

Guy on FB with an A1R just did this very thing (hooked up the batteries backwards).

Now he has Christmas lights for a dashboard (not strobing in sequence, but just all flashing at once) ...and a bricked truck it seems.

I still don’t understand how the LCBD didn’t protect his components. Seriously think he’s got something else going on

 

[Ronmar]

The LBCD should have protected the truck components, but the A1 has several connections, a disconnect switch and battery relay before the LBCD. Not knowing exactly what he connected and how, he may have completed a short circuit thru those connections and contactors. a weak connection could have cooked off and is now causing voltage delivery issues to the cab.

A very bad connection will still pass full voltage until you try and pull current thru it, then the voltage will fall off. In his video things are pulsing. I think the truck is trying to pull current, the voltage falls off and the devices shut down. The drop in current draw allows the voltage to pop up and the cycle restarts…