New Holland TC33DA - Engine Suddenly Stopped / Fuel Shutoff Solenoid OK

[VegasDan]

Hi Guys:
I'm a new member to this forum. I'm somewhat of a novice on tractor repair, but have some auto mechanic knowledge passed on from my dad. I own the above New Holland TC33DA and as I was driving forward, it stopped suddenly. After that, it would just turn over and nothing. I got great advice from several seasoned men to check the fuel shutoff solenoid by running a hot lead from the battery. It checked out fine, so now I need to troubleshoot what to do next (you can see the short video below where I did a temporary fix). Here are a couple other things I need to mention:

• The ignition switch could be going out because it takes several times of turning the key to finally engage the starter and kick over
  • I am ordering a Ignition Switch #86405634 from Messicks
• The glow plug light sometimes lights up briefly after the engine has started
• I believe the safety system is ok (PTO & Operator Seat)

A relay was mentioned, but that is where I need your wisdom. Looking at my manual (starting system electrical diagram), there appears to be several different relays. I'm guessing it's the Glow Plug Timer Relay? This is where I need your advice:

• Could that be the problem or is it something else?
• How do I diagnose this step? Am I missing something?
• Is there a video or PDF on removing my cowling to replace the ignition switch and get to the relays?

Thanks Guys!

[Here is the video I took yesterday on the bypass]

 

[dlctcg]

@VegasDan - I cannot confirm this as I do not have a TC33da or the correct diagrams... But on our TC40D (series) tractors here is some info:

The seat switch and the parking brake switch will not stop the engine from turning over. However they will cause the fuel solenoid to shut off... which will allow a engine cranking yet a No Start issue... (your situation) so you really need to make sure these circuits are working...

The neutral safety switch on the transmission & the PTO safety switch, these will stop the the engine from starting / cranking so I don't think they are the issue...

Again I don't have the diagram to your fuses & relays but you should have a Safety Start Relay, a Glow Plug Relay, & a PTO Safety Relay...& one of these relays could cause the same issues... but these are all separate from the Glow Plug Timer (different problem).

Again this is on the TC35 - TC45 series but to remove the two consoles / cowl panels...

To remove the cowling, you remove the bolts between the two sides under the steering wheel and then there are two bolts on each side of the firewall, visible when you raise the hood, that need to be removed. be careful not to force them if they are frozen...

One last thought... I know you are planning to install a new ignition switch.... at the same time you should plan to install the additional starter relay that has resolved so many issues for TC owners... Well worth it!!!

 

[thclimer]

@VegasDan - I cannot confirm this as I do not have a TC33da or the correct diagrams... But on our TC40D (series) tractors here is some info:

The seat switch and the parking brake switch will not stop the engine from turning over. However they will cause the fuel solenoid to shut off... which will allow a engine cranking yet a No Start issue... (your situation) so you really need to make sure these circuits are working...

The neutral safety switch on the transmission & the PTO safety switch, these will stop the the engine from starting / cranking so I don't think they are the issue...

Again I don't have the diagram to your fuses & relays but you should have a Safety Start Relay, a Glow Plug Relay, & a PTO Safety Relay...& one of these relays could cause the same issues... but these are all separate from the Glow Plug Timer (different problem).

Again this is on the TC35 - TC45 series but to remove the two consoles / cowl panels...

To remove the cowling, you remove the bolts between the two sides under the steering wheel and then there are two bolts on each side of the firewall, visible when you raise the hood, that need to be removed. be careful not to force them if they are frozen...

One last thought... I know you are planning to install a new ignition switch.... at the same time you should plan to install the additional starter relay that has resolved so many issues for TC owners... Well worth it!!!

You nailed it. The ignition switch is well documented as a weak link and the modification of adding a starter relay on its own circuit has helped many other owners.

I've attached a few pages that you may find useful.

 

[VegasDan]

@VegasDan - I cannot confirm this as I do not have a TC33da or the correct diagrams... But on our TC40D (series) tractors here is some info:

The seat switch and the parking brake switch will not stop the engine from turning over. However they will cause the fuel solenoid to shut off... which will allow a engine cranking yet a No Start issue... (your situation) so you really need to make sure these circuits are working...

The neutral safety switch on the transmission & the PTO safety switch, these will stop the the engine from starting / cranking so I don't think they are the issue...

Again I don't have the diagram to your fuses & relays but you should have a Safety Start Relay, a Glow Plug Relay, & a PTO Safety Relay...& one of these relays could cause the same issues... but these are all separate from the Glow Plug Timer (different problem).

Again this is on the TC35 - TC45 series but to remove the two consoles / cowl panels...

To remove the cowling, you remove the bolts between the two sides under the steering wheel and then there are two bolts on each side of the firewall, visible when you raise the hood, that need to be removed. be careful not to force them if they are frozen...

One last thought... I know you are planning to install a new ignition switch.... at the same time you should plan to install the additional starter relay that has resolved so many issues for TC owners... Well worth it!!!

Thank you for your reply.
I have attached the schematics for my TC33DA. Since I only want to do this once, do you think it makes sense to order additional components/relays; like you pointed out, maybe the seat switch & parking brake switch? I did order a "glow plug timer relay" along with my ignition switch. Do you have a preference on the companies you order from? Some of there web pages are quite confusing.

 

[dlctcg]

@VegasDan -

If I don't use my local dealer I pretty much use Partspring or Messick's

I'm not a big fan of just throwing parts at something... However, I would definitely do the addition of the Starter Relay, there is no downside to installing it.... & it is pretty easy...
For it you will need:
- A Bosch style relay (30 or 40amp) will work
- A inline fuse holder & fuse
- Some 14 gauge automotive grade wire (or 12ga)
- Some insulated .25" (quarter inch) freemale connectors (or relay plug with pigtails)
- Some miscellaneous connectors, like butt-connectors, ring terminals... etc.


Here is a pic of ours installed...


Below is the PDF explaining it (I believe originally posted by SteveinMD) showing the installation of the Starter Relay Circuit:


Again, I'm not a big fan of just throwing parts at something... I like to know what the issue is... instead of just rabbit-holing it it's fixed... I would do some quick diagnostics prior to just throwing parts...

As I mentioned in post #2, the seat switch & parking brake circuit will NOT stop the engine from turning over / cranking; it will still turn over the starter & the engine, but tractor will NOT start. This is because they shut off power to the fuel solenoid. I would check these first...

I would first try bypassing only the seat safety switch. It is simple & easy to get to... If it is the normal N.H. safety seat switch, with just two wires, you can just pull the plug at the switch & place a jumper across the two terminal in the plug.... If it starts & resolves the problem it is either the switch or your seat not making correct contact with it when someone is in the seat.... Also you can test the switch with a ohm meter... while you have it unplugged...

You can also check the relays... You can test them or just swap them for an alike one in the tractor for testing...

The fact your engine turns-over & does not fire narrows it down to the seat switch, fuel shutoff relay, the operator safety module, or fuel solenoid (which you ruled out already).

I think I have the testing procedures for the relays (but I would swap one first... just easier) & maybe the Operator Safety Module if you need them...

But check the the Seat Switch 1st... Then Relay... ect

 

[thclimer]

That's strange. I now see that my attachments did not post, they were the starting circuit mod schematic and the wiring schematic for the TC deluxe tractors, but I see you have your wiring schematics and dlctcg has posted the starting mod.

Good luck, hope your able to resolve your issue.

 

[VegasDan]

Thank you so much. I will take your advice and instead of throwing parts to fix my issue, I will try to determine what actually caused it. I will let you know what I find out. Again, thank you for the attachment and all the great information.
Have a great day!