Glow plug light.

[billdiesel]

2006 TC35A 240hrs, used a garden hose to spray it off earlier this week and now the glow plug light stays on continuosely. Runs and starts fine other than the light staying on. Closest I got to the engine was spraying the backside of the radiator. Any suggestions? Thanks.

[jinman]

You may have gotten some water down into the relays due to leakage around the steering wheel. . .not sure? The glowplugs staying on is a bad thing. You might check to see if it is just the light or if they are actually powered. You can pull fuse #1 for just a second to see if the light goes out. Fuse #1 cuts power to the glow plugs, but the glowplug light gets power from fuse 4. Therefore, if the light stays on, it's an indication that the lamp relay K9 has sticking contacts or a short due to water. The fuses are below your instrument panel on the left side. Fuse #1 is the first one on the left. It also controls your voltage regulator inside your alternator, so you will see the alternator light on also while the fuse is pulled.

If the light goes out when you pull fuse #1, you will need to take the cowling off below the steering wheel. There are two bolts directly below the steering wheel and two on the firewall on the left and two on the right side firewall. You can get to those by raising the hood. You'll need a socket extension to get to the bolts. I think they are 12 or 13 mm, but don't remember for sure.

Inside the left cowling (and probably covered with dust) is your relays. Relay K4 is the glowplug timer and is most often the culprit when the glowplugs stay on. I just replaced mine on my TC45D because the glowplugs were coming on at odd times and staying on too long. The timer is expensive, about $65, but that's what it takes to fix your problem. If the problem turns out to be the K9 light relay, then it will be cheaper, but I don't know the actual price. If I were a betting man, I'd bet on the glowplug timer K4 being bad.

[billdiesel]

Thanks Jim. I'll see what I can find out. So if the light stays on it's the K9 light relay?

[billdiesel]

Went out to the tractor to check the relays and decided to try it one more time before I tore it apart. It must have finally dried out, turned the key and the glow plug light came on and cycled like its suppose to. Hopefully all is well. Thanks for your help Jim.

[jinman]

That's the typical symptom when the glowplug timer relay starts to fail. Sometimes it works perfectly and other times it comes on and stays on at odd times. If you see this problem reappear (and I think you will) just replace the timer and you'll be set. $65 is a lot, but a lot better than burning up your glowplugs.

[fishpick]

And I was just about to ask "Is it normal to have the glow plug light come on, go off, start, come back on for a few and then stay off..." Sounds like it's time for me to go buy a new relay!

[jinman]

Buy the timer and keep a happy tractor at Chicken Thistle Farm.

[fishpick]

Picked up the relay the other day. Different part number than what the original part had on it but same relay. All you need to do is remove 4 bolts - 2 above the operator platform and 2 inside the engine compartment so the plastic cowling on the left under the steering wheel comes off. Then it's one small bolt, unplug the old and reverse operations to reassemble.
Relay cost $65.
Total work time - 15 minutes.
Now the glow plug light does what it should - turns off the second the engine is running!
Yeah forums for the time saver in diagnostics!
@jinman - happiness has been restored on the farm and the chickens are laying eggs now too!

[SuperCobra]

You may have gotten some water down into the relays due to leakage around the steering wheel. . .not sure? The glowplugs staying on is a bad thing. You might check to see if it is just the light or if they are actually powered. You can pull fuse #1 for just a second to see if the light goes out. Fuse #1 cuts power to the glow plugs, but the glowplug light gets power from fuse 4. Therefore, if the light stays on, it's an indication that the lamp relay K9 has sticking contacts or a short due to water. The fuses are below your instrument panel on the left side. Fuse #1 is the first one on the left. It also controls your voltage regulator inside your alternator, so you will see the alternator light on also while the fuse is pulled.

If the light goes out when you pull fuse #1, you will need to take the cowling off below the steering wheel. There are two bolts directly below the steering wheel and two on the firewall on the left and two on the right side firewall. You can get to those by raising the hood. You'll need a socket extension to get to the bolts. I think they are 12 or 13 mm, but don't remember for sure.

Inside the left cowling (and probably covered with dust) is your relays. Relay K4 is the glowplug timer and is most often the culprit when the glowplugs stay on. I just replaced mine on my TC45D because the glowplugs were coming on at odd times and staying on too long. The timer is expensive, about $65, but that's what it takes to fix your problem. If the problem turns out to be the K9 light relay, then it will be cheaper, but I don't know the actual price. If I were a betting man, I'd bet on the glowplug timer K4 being bad.

Thanks. I just went to order one because I've had this same symptom but it looks like the $65 relay is the K-9 (at least for the TC40DA). Not to make this seem like a knock because I appreciate you taking the time to post and save me a lot of trouble shooting but did you perhaps get the relay names/locations bassackwards? Looking at the Messicks diagram, K-9 is the glow plug timer relay:

New Holland TC40DA 4 CYL COMPACT TRACTOR

Anyway, thanks for taking the time to help us all out.

[jinman]

Thanks. I just went to order one because I've had this same symptom but it looks like the $65 relay is the K-9 (at least for the TC40DA). Not to make this seem like a knock because I appreciate you taking the time to post and save me a lot of trouble shooting but did you perhaps get the relay names/locations bassackwards? Looking at the Messicks diagram, K-9 is the glow plug timer relay:

New Holland TC40DA 4 CYL COMPACT TRACTOR

Anyway, thanks for taking the time to help us all out.

SuperCobra, you made one big error. You looked at the item number on the parts diagram and assumed it was the relay number. I know, I know it's confusing as heck, but item numbers are NOT relay numbers on the schematic. If you have a manual with the electrical schematics, you'll see relay K9 is indeed the lamp relay and K4 is the glowplug timer. On the parts list Item 8 is the lamp relay and Item 9 is the glowplug timer. It's just a coincidence. Frustratin' isn't it? Thanks for keepin me on my toes.