before you change your start box....

[MattNC]

A big thanks to the work done and posted on an old thread here on SS by 85 USMC M998. https://www.steelsoldiers.com/threads/6-2l-wait-to-start-light-not-coming-on.139538/

After driving the M998 all over the place the past month it just decided to no longer show the wait light or energize the glow plugs. Batteries were fully charged, truck turned over, but no wait light when cold (~36F) and no drop in voltage indicating the glow plugs were being energized.

I had the later version KSS smart start that was 5 years old, and was ready to have to buy a new box after all the connections checked out good. Reading around SS I found this old thread and decided to measure the resistance on the TSU on the cooling loop as he described. Mine was measuring all open (infinite resistance) for every pin combination, and I decided to try the $40 KSS TSU first. That was it. New TSU plugged in and she was back to normal.

Thanks SS thread archives and 85 USMC M998 for saving me a lot of time and money! Maybe a good first check before changing out smart start boxes that are now $$$$$. The TM's kind of skip over the trouble shooting idea that it could be the TSU and focus straight on the start box.

Matt in NC

 

[TOBASH]

Great you did this, and I respect your sleuthing skills.

Many of us just eliminate the TSU altogether with a more robust rebuild/restification of thenPCB/EESS garbage boxes.

I posted about it years ago.

How to bypass PCB? I am aware some HMMWV owners have done it.

I'm not trying to speak sacrilege here, and I don't want to precipitate a war of words. :shock: How might I build a manual control box? My 24Volt Landcruiser just uses a glow wire to show glow plugs are ready, and then she just starts right up with the twist of a key. Civilian 6.2 Diesel...

www.steelsoldiers.com

 

[MattNC]

Great you did this, and I respect your sleuthing skills.

Many of us just eliminate the TSU altogether with a more robust rebuild/restification of thenPCB/EESS garbage boxes.

I posted about it years ago.

How to bypass PCB? I am aware some HMMWV owners have done it.

I'm not trying to speak sacrilege here, and I don't want to precipitate a war of words. :shock: How might I build a manual control box? My 24Volt Landcruiser just uses a glow wire to show glow plugs are ready, and then she just starts right up with the twist of a key. Civilian 6.2 Diesel...

www.steelsoldiers.com

I was 100% ready to do this and was researching this work you described, but thought for $40 for a TSU that you just plug in, I might as well give it a shot before going the elimination route. Sometimes, not often, I am lucky! The diagnostic described was really easy as well. Pull off the harness plug from the TSU and just check for resistance/continuity from pin 1 to each of the others in order. For mine it was like 85 USMC, all were open.

 

[TOBASH]

Absolutely understand and happy you found the solution!

 

[FlameRed]

Deleted.