Solenoids in PCB........

[Cobra2401]

My PCB is bad in m939. I cut open the box and the one wire was burned out going to the one selenoid. Does anyone know how to tell which solenoids bad and as far as testing them? I was gonna replace the bad one or just the whole box if need be. I can post a pic tomorrow in the light. Thanks guys. Also any ideas what causes the box to burn out? Didn't wanna get a new one and have that one burn up too. I never knew til now, when you shut the truck off......you should shut the starter switch of. Then completely wait til the engine shuts down.....then shut the battery switch off. I always just would shut both switches off,one after the other.....without waiting for the engine to stop completely. Thanks again

 

[Suprman]

They are solenoid relays. You can actuate them with 24v and meter the contacts. They should probably both be replaced and are commonly available. Like any other high current relay the contacts wear out over time. It's a simple design and quite rebuild able. I would replace the damage wire also.

 

[Cobra2401]

Yeah Napa has each one for 45 and $70. Any ideas where I can find them cheaper or a whole new/used box cheaper?

 

[swbradley1]

http://www.eriksmilitarysurplus.com/elcoboxform9.html

 

[VPed]

Or: http://www.steelsoldiers.com/showth...ontrol-Box-(Black-Box)-for-M939-Series-Trucks

 

[Andyrv6av8r]

http://www.delcity.net/store/Solenoid-Switch-!-SPST-24V-100A-Insulated-Continuous/p_743395

Here are the relays. It's not a bad job to do yourself.

 

[Cobra2401]

Andyrv6av8r- I see that relay is the continuous one you found. Do they have the other one.....it's a intermittent one

 

[Andyrv6av8r]

Andyrv6av8r- I see that relay is the continuous one you found. Do they have the other one.....it's a intermittent one

I'm sure that they do but there is no problem with putting 2 continuous duty ones in there. I did and it works fine. You can't put a momentary in place of a continuous.

 

[Cobra2401]

What was wrong with yours? Mine, when you turn the battery switch on the selenoid it activates....the starter switch doesn't activate. I opened the pcb bozlx and the one wire was melted