Cheezwedge

Hello to everyone, I am fairly new to these forums and it already looks like a great place for owners and mechanics alike. I have been working on HMMWV's for the past 5 years in the US Navy Seabees.

I am trying to either compile, or find an already existing list of troubleshooting techniques for HMMWV's. What I have had in mind recently is something that would benefit military personnel who might either drive or ride inside a vehicle, possibly in a combat environment who has little to no mechanical or troubleshooting experience. I am trying to find a compilation of all of the "tips and tricks" of troubleshooting a HMMWV when time is of the essence, such as a quick fix over the permanent correct solution.

I am trying to find answers to some of my questions, as well as add some of the very useful things that I have learned that others should know. I have access to manuals so that isn't really the issue, I guess you could say I am looking for the "secrets" not in the manual, but acquired by years of trial and error as well as experience. I have been doing a little searching on the web but cannot find very much information. If anyone has any information on something like this, or any tips they could contribute then maybe I will just compile a list myself for the benefit of everyone, especially when it could help save lives.

(I know that there is a HMMWV school through GM, and some of this is taught there. Unfortunately very few people are able to be sent through that school)


This leads to my second question to which the answer is something I would like put on this list, and it has to do with glow plugs. (sorry I cant verify the model or year, possibly a 1097A2, or 998.) I believe the glow plug relay (clum relay?) is not cycling correctly and the glow plugs stay engaged for only about 1-2 (if that) seconds before starting the vehicle. Is there a way that anyone knows of where you can manually bypass or bridge the connection to cycle the plugs get and it started quickly?

This seems to be a very common problem on HMMWV's due to people not knowing how to cycle glow plugs, and eventually they either mushroom the glow plugs, or the relay goes bad.

I know this is possible on certain CUCV's where the connections are exposed and can be bridged with a long bolt or something. Yes it sparks a bit, but it works.

As far as a solution I found when a HMMWV would not start due to that glow plug problem (I attribute this to my friend who actually got it started, and i think that the model was a 1097A2, possibly a little older), here it is:

He covered exhaust pipe with his hand, which was enough to raise the compression and ignite the fuel. Now there may have been more serious problems with that vehicle, but I never got a chance to find out. All i know is that it was spitting out unburned fuel fumes through the tailpipe, and that quick fix did it and allowed us to move it. This little "trick" that wasn't in the book was very useful in my opinion and is something everyone should know just in case you are in a sticky situation with a down vehicle.

So this is my little contribution, and if anyone else has any similar experiences, or knows of resources that contain useful tips for HMMWV's (or even Oshkosh MTVR's) it would be greatly appreciated. Thank you.

fobrat

A good place to find stuff like that is www.themotorpool.org. There are alot of little tricks you could find there. As far as the glow plug system a good way to truble shoot it is that when you turn the start switch to run and you have no wait light the PCB box is bad, when it flashs the controler is bad, when the light comes on like it should and there is no draw on the voltmeter the glow plugs are bad, and when the wait light comes on for a second and gos off it also means the glow plugs are bad. The glow plug system cannot be bypassed cause the relay is inclosed in the PCB box.

__________________
SSG Gary Matt
Field Maintance Shop #6
Utica, New York

emmado22

So your looking for BDAR fixes? Call the TACOM BDAR guys at APG. There isnt much "special" about the HMMWV in terms of BDAR that isnt a common BDAR fix across all wheeled vehicles.


In today's current Army combat maintaince mentality, if a truck goes down, it gets recovered to the UMCP via towbars, tow chains, flatrack, whatever.... Fixing it isnt the main issue at that point.. It's getting it back to the FOB (or more importantly get the crew out of danger, which both happening is the best solution) or behind the wire where mechanics can look at it.

Army Ed

geez i was gonna write the same thing...lol..Ya HMMVV's arent special enought to get secret tips...lol..we have so many come in and out of our shop that i lost hope for em...lol..so many issues,blown seals like its no one business and transfer issues.it never stops..lol

HUMMER1

Hello everyone,

just wanted to chime in that there is a BDAR manual that covers only the HMMWV family and there are alot of fixes in it specific to just the series. Especially if your in combat zone, or even just to keep you moving to a shop. Fair warning though the manual only comes with a very expensive BDAR kit through supply. Give me a little bit and I will post the NSN. or just drop me an email.