Glow Plug Issue

[hollywd75]

Hello,

I bought a 2004 TC30 a few months ago, the glow plugs don't seem to work. I've never had a tractor with glow plugs before so this is all new to me. I'm not much of a mechanic, more of a 'learn as I have to when things don't work.'

I did just replace the glow plug timer, as I read that is a common failure. Tried to turn on glow plugs - light on dash came on - good news.
In replacing the timer I noticed the wire to the glow plugs wasn't actually plugged in (aha!). Plugged wire back in.
Tried to turn glow plugs on - no dash light now.
Unplug wire - turn on glow plugs - dash light back on.
Does this mean the actual glow plugs are bad? Or some kind of short somewhere that happens when the glow plug wire is plugged in?

In all this the tractor still won't start. It is chilly, in the 30's. We have never been able to start it without ether, which I don't like doing so I really want to get this fixed. We haven't had it very long and have only run it maybe half a dozen times so I don't know it well enough to know what is normal and what is not for this tractor.

I did hear ether + glow plugs is very bad so if I need to run it I don't even try the glow plugs just in case. I was considering getting a block heater, I think Tractor Supply has them, has anyone had good luck with those?

I'm guessing next step is to test the actual glow plugs?

I was going to look for a video on how to use a multi meter to test things, I've used one a few times but am no expert there. You can use them to test for shorts, correct?

I also found a random black wire that I have no idea where it plugs into (see photo). I didn't know if it was related to this issue. I tried looking at the wiring diagram but I couldn't figure it out. The glow plug wire is unplugged in the photo.

I do know the previous owner replaced and moved the ignition switch to the left side so I don't know what wiring modifications (if any) were made.

Any help appreciated!

 

[Roadworthy]

If the prior owner has done significant rewiring nobody here is likely to be able to pinpoint your problem. I will tell you sometimes glow plugs fail as a dead short instead of going open. You could certainly try replacing them or at least testing them as a first step. If removed from the tractor they may be tested individually. Frequently 10.5 volts is the correct voltage. You can get proper replacements directly from NGK without going through the tractor dealer.

 

[TractorTech]

You can also just get a temporary jumper wire and hook to the glowplug wire or to the flat bar on the glowplugs for about 20 seconds to start it rather than ether.
1-6 ohms is the resistance of a typical glowplug that is good. Remove the flat bar on the glowplugs and test each one.

 

[hollywd75]

If the prior owner has done significant rewiring nobody here is likely to be able to pinpoint your problem. I will tell you sometimes glow plugs fail as a dead short instead of going open. You could certainly try replacing them or at least testing them as a first step. If removed from the tractor they may be tested individually. Frequently 10.5 volts is the correct voltage. You can get proper replacements directly from NGK without going through the tractor deal

Thank you - I haven't looked under the dash yet to see what the wiring looks like. That was going to be a spring task.

 

[hollywd75]

You can also just get a temporary jumper wire and hook to the glowplug wire or to the flat bar on the glowplugs for about 20 seconds to start it rather than ether.
1-6 ohms is the resistance of a typical glowplug that is good. Remove the flat bar on the glowplugs and test each one.

Good to know about the jumper wire for starting - will look into testing the plugs next.

My last tractor was an IH 454 and it actually had a button in the dash for a small canister of ether stored near the engine to start it, lol. No glow plugs, of course.

 

[hollywd75]

Pulled the glow plugs and tested, all three no readings. Ordered a new set, tested them and got readings, just installed them.

Same issue, won't start. Tested for voltage at the glow plug connector, got 12v.

If the glow plug connector is unplugged, the glow plug light on the dash comes on when activated. When I plug the glow plug connector in, then the dash light won't come on.

I've read other posts and people talk about a click coming from the timer. I am not hearing any click. I replaced the timer, no click from the new timer either.

It is pretty cold out, been around 25-30. Tractor is kept in a shed. Is it just too cold for the glow plugs? I was going to go buy a block heater next and try that.

 

[grsthegreat]

Have you talked to NH mechanic? My Kioti has a controller and a relay for glow plugs. The controller adjusts time of run for plugs according to temps ( or so I was told).

 

[grsthegreat]

Does the NH cycle glow plugs by partially turning key either right or left? For manually running plugs

 

[hollywd75]

Have you talked to NH mechanic? My Kioti has a controller and a relay for glow plugs. The controller adjusts time of run for plugs according to temps ( or so I was told).

I have not. I was hoping it was just a bad glow plug or timer as I hear that is a common fail, but no such luck. I have yet to hear the 'click' that people talk about.

According to a TC30 manual I read you are supposed to turn the ignition key backwards to engage the glow plugs. Mine seems to be different though. I have a switch that I pull out. I know the previous owner replaced the ignition switch (someone had broke a key off in it), so I'm wondering if he rewired the glow plugs to a separate switch. Now I'm wondering if he didn't connect something right - thinking I may need to look behind the dash now. He had told me the glow plugs worked though.. hmm.

 

[mjonesnh]

I have not. I was hoping it was just a bad glow plug or timer as I hear that is a common fail, but no such luck. I have yet to hear the 'click' that people talk about.

According to a TC30 manual I read you are supposed to turn the ignition key backwards to engage the glow plugs. Mine seems to be different though. I have a switch that I pull out. I know the previous owner replaced the ignition switch (someone had broke a key off in it), so I'm wondering if he rewired the glow plugs to a separate switch. Now I'm wondering if he didn't connect something right - thinking I may need to look behind the dash now. He had told me the glow plugs worked though.. hmm.

Don't have a TC30 but a TC34. There is a click to mine when glow plugs are active and have cycled. 1st indent on key turns on glow plugs for 4-5 seconds then a click, turn key to last position to engage starter then release key to spring back to run position, Believe there is another relay tied to glow plugs besides timer, at least on my model