Another EEES / Prestolite Box debacle.

[UserError]

Alright folks, I've ran into a bit of a jam.

I had a no start HMMWV, ordered one of those KDS green label boxes. Works great. Now my buddy has the same issue, so we decided to pull apart the box he took out of the no start truck and see if we couldn't fix it.

The outside of the box has a silver label that says Prestolite Control Box. NSN 6110-01-395-9585. MFR 7E656

Inside the box is a small PCB with 2 transistors 3 FET's and a gaggle of diodes and resistors. Doesn't appear to be much in the way of logic on the board, i don't see any timer chips but I'm not much an electrical guy either. These are just my best wild ass guesses.

Also inside the box are 3 solenoids. 2 look like your typical ford firewall mount starter solenoid with plastic bodies, no markings on them what so ever. the 3rd {middle} solenoid is a regular metal canister type.

Upon inspection the left hand outside plastic relay {top relay in the picture} with the yellow wire coming off it is not clicking. I don't see anything obviously blown up on the PCB so i figure one of the relays is bad. I take the no click relay out of the box and drill out the rivets. To my surprise the relay is EMPTY. Nothing inside it!

Is this relay SUPPOSED to be a dummy relay? or did i just get a box thats been bad all along? This is the box was installed in the HMMWV when it was purchased from GP. Im a bit lost on where to go from here.....

Here are a few pics from inside the box. As configured, the relay that doesn't click and finally the relay that doesn't click opened up.

 

[juanprado]

So the wires going into the blank solenoid do not connect to anything and there are no contacts?

Sounds like a factory manufacturing defect and crazy to think the military did not change the box. Also says alot about prestolite's quality control and no testing...

I would put a new solenoid in for giggles. Cheap fix. Very common solenoid, just need to get a 24v version.

 

[NDT]

Too funny. Prestolite's qc testing missed that. No wonder Uncle sent the truck to DRMO: "thing won't start even with a new box!!" Actually, things sometimes happen in manufacturing. We shipped an entire shift of residential A/C units with no fan blade. Supposed to install later but the whse shipped them anyway! Heads rolled over that.

 

[UserError]

It actually looks like maybe the box was opened up one other time before i got to it. The cork gasket had black goop on one side and clear goop on the other. There were arc marks inside the box, all around the "empty" relay. I was thinking maybe they diagnosed a bad box, replaced it and got the same result and said Eff it, off to the Drmo she go!

Anyhow i replaced the solenoid with a new one, i was trying to convince myself that relay was a defect and not supposed to be empty for some crazy reason. But not having any sort of schematic made me a little nervous.

Box is all back together now with a new relay, will toss it in the truck in the morning and see if she'll start cold now. I will report back what i find.

Thanks!

 

[UserError]

Stuck the box in teh truck, and she fired right up! No magic smoke to report so i guess this was just another case of awesome QC.

25 bucks was alot better than 350 to get it back in the fight

 

[DrOfData]

ANy chance you have the P/N you used for the replacement solenoid & where you got it for $25?

 

[papakb]

This type of information is what makes these forums so valuable.

 

[snowtrac nome]

Sounds like prestolite is out sourcing to lucas , those who have worked on a land rover, or triumph know what im talking about.

 

[papakb]

Ah, George Lucas, inventor of the short circuit!

 

[pjwest03]

Joseph Lucas, actually. Generally referred to as the Prince of Darkness when some Lucas made auto lighting showed up in the US. Somewhat unfair to the man as he died in 1903 and was in the business of manufacturing oil lamps for bicycles at the time.

Also, Prestolite did buy a piece of Lucas in the late 90's.

 

[snowtrac nome]

Joseph Lucas, actually. Generally referred to as the Prince of Darkness when some Lucas made auto lighting showed up in the US. Somewhat unfair to the man as he died in 1903 and was in the business of manufacturing oil lamps for bicycles at the time.

Also, Prestolite did buy a piece of Lucas in the late 90's.

The comment was intended to be a joke to tickle a funny bone, but as Paul Harvey would say now you know the rest of the story.