Glow Plugs

   / Glow Plugs #1  

ctjstr

Silver Member
Joined
Sep 7, 2007
Messages
119
Location
Orting, WA
Tractor
New Holland TC35D
Just curious if anyone has run into this. On my TC35D, when I start it for the first time on any day, the glow plugs do not activate with the key as they should. Every other time from then on during the day, they activate properly. Its just that first time.

I'll tear into the switch and stuff if I have to, but I'm wondering if that's a common problem with an easy fix. Thanks

toni
 
   / Glow Plugs
  • Thread Starter
#2  
BTW, I did read several of the posts about problems with the timer relay on this and similar models. Those symptoms seem a bit different and I'm just not sure if its the same thing or not.
 
   / Glow Plugs #3  
In reading this, the only think I can think of is a bad relay. When you start it the first time, the battery has its lowest voltage. After running for a few minutes with the higher voltage from the alternator, you would have a slightly higher voltage. Perhaps this is just enough to get the faultly timer to function normally. That's the only way this makes any sense to me.
 
   / Glow Plugs
  • Thread Starter
#4  
That makes about as much sense as anything I've come up with. Just for giggles, I'm going to check battery voltage before I turn the key and see what's up. Its a relatively new battery so I'm a bit skeptical, but who knows. I'm just glad I'll be able to sort this out on my own (with help from this group) rather then having to haul it in. I just can't imagine what a pain it would be to have to haul stuff to the dealer for all sorts of little stuff. Frankly, its one reason I don't care about buying stuff with warranty. Absent a catastrophic failure, its usually easier to do something yourself then fuss with the dealer. At least that's the way I'm justifying it right now. probably a way different tune if this was something big.:eek:
 
   / Glow Plugs #5  
Battery will probably test fine; the relay has the issues. Just as Jinman says.
 
   / Glow Plugs
  • Thread Starter
#6  
yup. Battery fine. Sometime this weekend I'll have to root around and find the relay, figure out what energizes the glow plugs and wire up my own switch. I've got tons of relays laying around and I'll be dipped if I'll pay 50 bucks for one.

(yeah sure....what will REALLY happen is I'll fuss with it for a few hours and THEN buy the factory relay)
 
   / Glow Plugs #7  
ctjstr said:
yup. Battery fine. Sometime this weekend I'll have to root around and find the relay, figure out what energizes the glow plugs and wire up my own switch. I've got tons of relays laying around and I'll be dipped if I'll pay 50 bucks for one.

(yeah sure....what will REALLY happen is I'll fuss with it for a few hours and THEN buy the factory relay)

They don't make this circuit easy to figure out. There are three relays: glow plug timer, glow plug power, glow plug light. The timer relay controls the glow plug power relay by opening the ground path to it's coil. The glow plug power relay has two contacts. One set powers the glow plugs and the other supplies power to the glow plug lamp relay's coil. It is possible for the glow plugs to be working fine and the lamp not indicate. However, if the timer is not working, neither the glow plugs nor the lamp will operate.

According to my circuit diagram, the timer is relay K4, the glow plug power relay is K3, and the lamp relay is K9. If you are looking at your relays from the left side of of your tractor. The timer is the relay on the lower left with the "tongue" that has a philips head screw holding it in place. It has three wires in a plug right below it. I believe the connector number is C-16.

Hope this helps you "root around" a bit.
 
   / Glow Plugs #8  
<ahem> excuse the interruption...

Your circuit diagram?

That's one thing i was interesed in - shop manuals, wiring diagrams, etc. I just got my TC-18 and ll i have are the owner's manuals. Would a dealer have them, or do I have to get them from NH directly?

Thanks, & good luck with the relay!
 
   / Glow Plugs #10  
TomOfTarsus said:
<ahem> excuse the interruption...

Your circuit diagram?

ToT, the circuit diagram I was using is in the back of the Owner's Manual that comes with the tractor. Did you not get that with your TC18? I have circuit diagrams in the Repair Manuals I own, but the one in the Owner's Manual is fine for most troubleshooting. The location of the relays came from the Repair Manual.

Your dealer should be able to get the manuals for you, or you can buy them online from NH. They have printed manuals and manuals on CD. They are quite expensive. The CD is about $84 and the printed manual set is about $312. Messicks.com shows the Owner's Manual as selling for over $45.

Here is a link to the NH website:

NH Tech Pubs
 
 
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