TC 29D intermittent glow plug light when preheating

[Jakesta49]

Hoping somebody could help me with this question. I have a TC29D. recently I have noticed that when I try to preheat my glow plug light does not always come on. A couple of times it would come on when igniting switch was turned to heat and tractor was in gear. I would then shift to N and start her up. I have realized that it doesn't always work. I do know that even if the preheat light does not come on when I am trying to preheat it ALWAYS flashes on for a second when the engine is actually turning over. I figured there was a short somewhere. Does the fact that it ALWAYS flashes on for a second rule out the idea of a "short"?

 

[jinman]

Jake, do your glow plugs seem to operate even though the lamp is not illuminated? Without the electrical schematic for your tractor it's hard to give details, but in general, when you turn the key to preheat, there is a timer that operates the light and sends a signal to the glow plug relay. Thus, the glow plugs work off of a separate high current relay. Probably one of these has dirty contacts causing the light to be intermittent. I don't see any indication of a short. Something may not be making contact, but not shorted. If something shorts out, you'll normally blow a fuse.

 

[Ohio Paul]

I would take a close look at your ignition switch. New Holland is not known for quality switches, especially if you have alot of other keys hanging on the ignition key. It is easy to replace and cheaper at NAPA.

 

[brin]

I have a TC - 29 D that I bought new in 2000....I always hold the key for 8 to 10 sec but the glow plug light never goes out....I have tried holding it for 20 sec. and the glow plug light never went out...it always starts right up but I have always wondered why my light won't go out when the glo plugs are heated up....??????

 

[jinman]

I have a TC - 29 D that I bought new in 2000....I always hold the key for 8 to 10 sec but the glow plug light never goes out....

That's why I feel funny giving detailed advice on the Class II Boomers. I don't have one and don't have a schematic. I'm pretty sure that the glow plugs time out and go off and the light stays on to tell you that you have the key in that position, but I could also be full of prunes.

 

[brin]

That's why I feel funny giving detailed advice on the Class II Boomers. I don't have one and don't have a schematic. I'm pretty sure that the glow plugs time out and go off and the light stays on to tell you that you have the key in that position, but I could also be full of prunes.

Thanks Jim, that must be what is happening with mine...I do notice though even in 90deg. weather...I have to hold the key on the glow plug position for at least 10 sec. or it won't start...so it's not just needed in cold weather for my tc-29....

 

[bartonkj]

Hey guys. I have a TC 29D (or DA - can't remember.) I've had it since new. I have the same problem. Here are more details:

1) glow plugs sometimes work, sometimes do not work
2) glow plugs work when the light illuminates
3) glow plugs do not work when the light does not illuminate
4) glow plugs sometimes stay on for quite some time after the tractor has started
5) if the weather is warm enough I can start without glow plugs (after cranking engine for awhile)
6) no fuses are blown

I do not think it is the ignition switch. I had to replace my ignition switch I have this problem with the new switch (unfortunately I cannot remember if I had the problem with the old switch.)

I talked to the dealer service department and they think it could be the glow plug timer relay, but I haven't bought a replacement yet - my dealer charges $35 plus tax for it....

 

[jinman]

What you need is a glow plug timer relay. It's listed on the TC29DA parts list as SBA385870301 and is about $80. You have to pull the right side cowling underneath the instrument panel to get to the relays. In the illustration below, your right side relays are shown. The timer is item #2.

BTW: If you want a cheaper alternative, you can buy this one on eBay. It comes with a lot of extra stuff you don't need, but it's only $12.99.