Komatsu D20A6 Glow plugs and indicator

[swartb]

Thought I would pass along a little experience on the glow plug system on a D20A6 Komatsu. I experienced a burned indicator. Thought that it was old and possibly reached its natural life. Ordered on from Komatsu dealer, installed it and immediately fried it. So, had to order another, but not without some troubleshooting. Simple system runs from ignition switch that powers in both "heat" and "start" positions. Power runs thru indicator, to connector, to number one glow plug. There is a rail that connect power to all four glow plugs. Did some research on glow plug diagnostics on the web and there is some misinformation out there. Some say if the glow plug is not open, then OK. Not true. Glow plugs do go to ground and it is difficult to diagnose as the OHM resistance is small. Had one open and one "questionable". Ran a wire from #1 to #4, bypassing #2 (open) and #3 (suspect). The indicator functioned normally but experienced a long "glow" period. As far as the indicator goes, I went to the local Appliance Store and the owner looked at the "glow indicator" and said, I might can help. He came back with a PN 2RW460A 24601 dryer (I think) element. It was about 3ft long and the perfect nichrome wire already coiled in 16ga/1mm thickness and just the right coil diameter. I cut a piece about 12 coils, unwound, straightened both ends, made a curl on each end for attachment to the indicator housing screws (leaving 7 coils for "glow"). Hooked it up to the glow indicator housing and it works perfectly. So, now I have lots of the proper wire for future use. Just posting in hopes it helps someone else.

 

[tantoy]

Thanks for posting, I will remember that for my d21a if I have issues.

 

[GuglioLS]

You wound up a good solution with the Ni Chrome wire off a dryer element. I am interested in how long it takes for the glow of your new indicator to reach peak brightness and stabilize?

That glow plug indicator on my D20A-6 burned out too, maybe from leaving the glow plugs on too long? When it failed, I pulled it out then used a hole saw to punch a 2" hole through the dash, then fitted in an amp meter. The glow plugs on mine draw around 35 amps when cold , then rapidly and steadily drop to 25 amps in about 10 - 12 seconds then I fire it up. Glow plug resistance measured with an ohm meter will be near dead short on a cheapo meter (less than 1 ohm for all 4 in parallel) as the elements inside the plugs heat up resistance increases drawing less current.