Anyone bypass the PCB?

[kfrosty]

I'm just having the fortune of experiencing the no start issues. I've had my M998 a couple of weeks, the one good thing about it was how well it starts. Then today I need to move it and all of a sudden, the PCB just clicks when you try to start but nothing from the starter.

I hooked a slave cable up from my 5 ton in case the batteries had been drained but doesn't make a difference. One thing I notice is a click and the voltmeter dropping while start switch is in the run position. I think that has something to do with the glow plugs.

I've been searching through threads for an hour about wiring harnesses, replacement easy start boxes etc. But I've been thinking, why not just bypass the control box all together? Wire the glow plugs to a switch and use them when needed.

Then the start switch directly controls the starter and fuel shut off. Has anyone tried that? I haven't fully gone through the TM and completely thought this through but I don't like the idea of a bad glow plug or something frying an expense box and leaving me stranded somewhere.

Thoughts?

RetiredWarHorse, I left you a vm about a EESS.

 

[TedG]

I had a hmmwv that this was done to. It worked fine as long as you were not overheating the glow plugs buy keeping the lit up too long.

 

[86humv]

They used to do it to CUCV's with a spring loaded switch, ,.......count to 9 and let go, then start it.

 

[kfrosty]

Posting details for future reference. This evening I got to troubleshoot some more. I went ahead and put together the ground harness. The starter still wouldn't turn over. I get the wait light normally. It goes out and when you try to start you hear the clunk in the PCB but nothing. If you leave the switch in the run position, you can watch the volt meter fluctuate. When it does there is a clunk in the PCB which I think has to do with the glow plugs.

Then I tried to jumper the start to see if it would bump. Nothing. So then I got out my volt meter and put the switch to start and realized I'm getting power to the wire on the solenoid.

Really odd as the starter has been strong the few weeks I've had it. Starts as soon as you bump the switch.
Then all of a sudden nothing.

 

[Trailboss]

Had a no-start problem with a M931A1 last week that had cranked and ran 3 times the week before. Even jumping with another truck the starter would only click once. Charged the batteries for 2 days and tried jumping again. Turned out one of the batteries was bad, even though the voltage showed good with a meter and the gauges worked normally. When I put a load tester on it, it showed that the one battery out of 4 was bad. Swapped in 2 type 31 batteries and it cranked right up.

 

[kfrosty]

Just put brand new batteries in last week. Starter won't click or do anything.

 

[Retiredwarhorses]

Have you checked/bypassed the neutral start switch? Or....is the shifter in Neutral? Gotta ask bro....

 

[kfrosty]

Have you checked/bypassed the neutral start switch? Or....is the shifter in Neutral? Gotta ask bro....

Thanks. Power is getting to the wire on the starter solenoid so wouldn't that mean that the neutral switch is working? But regardless, I have tried the trans in neutral and then in gear. In neutral, you hear the clunk in the PCB. In gear, nothing which is normal.

Note, I put mine in gear when I'm out just so somebody just hit the start switch and have it run without knowing what to do so that's usually the first thing I do getting into my MV's now.

To bypass everything, you should be able to jumper power to the wire on the starter solenoid, correct? Even that does nothing.

 

[Retiredwarhorses]

Probably a bad solenoid on the starter....hit it with a hammer.

 

[kfrosty]

Probably a bad solenoid on the starter....hit it with a hammer.

Haha, late last night I was trying to hit it but hit everything around it. Plan on taking it out today or tomorrow and tapping on or replacing it.

Anybody know of a part number at a Napa or retail parts store that would match up and work.

 

[Retiredwarhorses]

Haha, late last night I was trying to hit it but hit everything around it. Plan on taking it out today or tomorrow and tapping on or replacing it.

Anybody know of a part number at a Napa or retail parts store that would match up and work.

once out of the truck, you test the solenoid with a single 12v battery.
and no, you will most likely need to find solenoid or just replace the entire starter.
Or send it out to rebuild...easier to buy a new one on auction sites

 

[gcbennet]

I've got an S3 box that does everything it's supposed to except start the truck. The same issue on another thread (either here or in the G, can't remember) the owner dissected the box and found a stuck relay to be the culprit. The easy fix is to replace the box. If you know an electronics SME, they may be able to diagnose and replace U/S components.

 

[DatGuyC]

For all the money the military spends, you would think they could design a glow plug control system for the HMMWV that wasn't complete ****. Had my KDS S3 box break for the 3rd time yesterday. Went out to start the truck and noticed no wait to start light or power drain on the volt meter. It was sorta warm outside and the truck was sitting in the sun so I thought maybe it was warm enough to not need them. It started after a couple cranks but not as fast as it usually does. It was fine when I last drove it sunday and hadn't been touched since then, so the box broke without anything happening, and I have the grounding harness.

I'm doing my body lift today so I move the truck in the garage and again no light or anything, so I figure the box is definitely bad since its not sunny so the truck isn't that warm under the hood. I put the truck in the garage and turn it off and figure I'll just replace the box after I'm done with the lift. Maybe 30 minutes go buy and I'm on the drivers side and notice that warm electrical smell. I put my hand on the generator and its warm to the touch, which isn't good since I only moved the truck a little and the engine didn't get a chance to warm up. I disconnect the battery and hear a click which I figure is one of the relays in the S3 box resetting, it must have been holding open or something and doing something to the generator. I'm hoping it didn't fry anything. I'm done with this **** thing and wont be using it again. I'll just leave my Nartron yellow label box in the truck after I swap the S3 out.

 

[gcbennet]

I'm on my 3rd S3 box now in less than a year. One goes through the wait cycle but no start. The other won't cycle and draws battery power even with the switch off, and has the audible clunk when the neg battery cable is unconnected/connected. The newest box worked fine at first but started drawing power like the second box was doing. For whatever reason that has since stopped but now the box bounces back and forth between normal operation or flashing wait light. It bothers me that this is a common fail item that makes the truck inop without notice that can't be easily repaired. It seems to go against the military concept of field-expedient repair. I suppose they get around this by making the box itself simple to replace when it fails- and I do mean 'when'.

 

[nickd]

Guys,
I have owned mine for 5 years. The first thing I did was install a kill switch to prevent unauthorized starting of my vehicle. The switch disconnects the negative terminal by disconnecting the ground. I have not had any trouble with my "smart box"

 

[drivebymashing]

Haha, late last night I was trying to hit it but hit everything around it. Plan on taking it out today or tomorrow and tapping on or replacing it.

Anybody know of a part number at a Napa or retail parts store that would match up and work.

So 2 years later ... was this a starter or pcb problem?