DX 33 Starting Problem Fixed

[cardenharry]

I have been plagued by the starter solonoid clicking now for about a year and have read the various post by others at this sight. I did not experience a blown fuse. Today I installed the 30A relay that others have reported using to fix a low voltage problem and the starter comes to life like it has 24 volts going to it. The fix appears to be working as there have been no failures today. I did install a relay purchased at a local Napa store. I had not realized that local parts places would carry a relay with the pin numbers 30, 85, 86,87 as others on this sight have shown. Mine also had a pin 87a which I left blank. Member Farmall Aces helped me understand that. Thanks. Also thanks to Radiopoor, Ron and others who have contributed instructions on this.

 

[SteveInMD]

Glad to hear you resolved it. Could you post a cross reference list of NAPA vs NH part numbers? I think there are many people that could benefit from it.

 

[thclimer]

This sounds like this fix everyone needs to perfom who has had starting issues. I wonder if anyone could sketch the circuit diagram showing how the additional relay is wired into the existing starter circuit?

 

[cardenharry]

The Napa relay I purchased shows part # AR276
I also purchased a plug with 4 wires that plug into the relay part EC23. You do have to make sure the 4 wires are in the position to contact pins 30, 85, 86, 87 (and not 87a)
There are detailed pictures on this site from Jsheds. For those interested a search under TC33DA-Starting problems will furnish good instructions. I basicly followed the instructions that others furnished on this site.
(1) Relay installed under plastic on left side down low in a vacant hole in the steel plate. Attached the inline fuse 30A on the engine side on the same bolt.
(2) Ran the wire from pin 30 thru the inline fuse and attached at the bolt holding the battery positive to the starter.
(3) Ran the wire from pin 85 to ground. I attached to a bolt under the clutch area that holds a hydraulic line. (need a loop end here just like what is needed to attach at the starter.
(4) Unplugged the white plastic connector from the back side of the starter solenoid and cut it off along with a few inches of wire. Connected this white connector to the wire from pin 86 and plugs back to the solenoid.
(5) Take the cut wire that previously went to the solenoid and connect it going to pin 87 .
I saved pictures and instructions on what others posted and printed them out for instructions to follow.

 

[SteveInMD]

Well, I'm no expert at drawing circuit diagrams, and PowerPoint doesn't seem to supply standard circuit diagram objects to insert, but I did what I could. The attached PDF file is three pages showing the original circuit, the completed alteration to the original circuit, and finally the new starting circuit. There are things missing from the diagram, such as the original fuse, but since you don't touch that part I left it out to keep the drawing simple. The circuit is more complicated than I have shown, but it does show you what you need to know to complete this fix. I tried to use the same wire colors as Jsheds describes where I could, but the white wire was hard to draw on white paper. Let me know if this needs any clarifications and I'll do what I can.

 

[SteveInMD]

Did anyone find this useful?

 

[CCWKen]

Yes, that is a useful diagram. It highlights were the actual problem lies--The key switch or safety interlocks. Seems that adding another level of connections (relay contacts) is adding more faults to the system. At some point, the resistance in the key switch or interlocks will become higher and the relay will fail to trigger. Is it then proposed to add another relay to trigger this relay?

 

[SteveInMD]

I believe the problem is in the series of interlock switches. The solution works because it only takes a few volts and very little current to trip the relay. However, the starter solenoid is much less tolerant of low voltage. A relay is a mechanical switch and it can fail, but it most cases they are very reliable and will likely outlast the tractor. It is possible for the interlock switches to become so dirty or corroded that they completely stop the current flow but we haven't have any reports of that yet. Remember, this is a standard method of increasing the reliability of a starting circuit; not just a crazy idea dreamed up for this tractor.

 

[dqdave1]

I believe CNH is now using the relay in the starting circuit on new production. This says that it must be a proven solution to the system.
All the relay does is make sure that 12 volts is getting to the starter solenoid. I have heard that in the old circuits, it was dropping to 10 volts.

 

[MikePA]

Let me know if this needs any clarifications and I'll do what I can.

Great drawing, Steve! The only way I can see to improve it would be to include the relay part number, the fuse holder part number, wire size and and anything else that would be needed to implement the fix. That way people could use it both as a shopping list and instruction list. Some (all?) of this is listed in other posts, but having it in one place would be great.

 

[thclimer]

Did anyone find this useful?

Hi Steve,

I've been away from the Internet for the last few days. This is a terrific drawing, thanks for your time and effort you put into it. I believe many owners will be using it in the future.

Tim

 

[SteveInMD]

Here's the drawing with part numbers and notes added...

 

[thclimer]

Here's the drawing with part numbers and notes added...

Now there is no excuse to not perform this conversion if you are having problems.

 

[cardenharry]

With reference to the inline fuse between the battery/starter cable and the 30A relay. In an earlier picture I believe I saw a 40A fuse. Since it is listed as a 30A relay I used a fuse holder with a 30A automotive fuse. I noticed that SteveInMD showed a 10A fuse. Just wondering what others feel should be used here and why. Anyway, used my tractor today and it started just as it should.

 

[SteveInMD]

I though this issue might come up.

I believe there is a difference in where I picked up power from the method posted by Jsheds, but I could be wrong. It wasn't clear to me. This might account for the different fuse recommendation. I can tell you that my tractor starts just fine with a 10 amp fuse. If you run a 40 amp fuse you will burn up the 30 amp relay before the fuse blows. With my diagram a fuse smaller than 10 amps may even be sufficient. Tomorrow I'll use an ammeter to see what the max current is with the new circuit when starting under normal conditions.

 

[SteveInMD]

I chose a 10 amp fuse since that's what the original circuit called for.

Since I'm having trouble locating my ammeter, I did the next best thing. I inserted a 5 amp fuse and tried to start the tractor. It started twice, but on the third try the fuse blew. I attribute this to a slightly lower battery voltage after the third glow plug cycle. And of course as volts go down, current goes up. I then put in a 7.5 amp fuse. I started the tractor a number of times with no problem. Therefore the current under normal conditions must be more than 5 amps but less than 7.5 amps. I'll leave the 7.5 amp fuse in for a while and see what happens. I think a 10 amp fuse is about right. If the tractor sits for a while and the battery isn't topped up the 7.5 amp fuse may blow when you try to start it.

I think the fuse needs to be less than 30 amps to protect the relay. A 25 amp fuse may be acceptable, but a 10 amp is more conservative.

 

[thclimer]

Hard to beat the data from an actual test; like you said 10 amps is probably a very good place to start.

 

[dqdave1]

Am I wrong, or does the inline fuse protect the newly installed relay? I just did this and CNH gave me a 25 amp fuse to protect the 30 amp relay. The original fuse will still protect the start circuit.

 

[SteveInMD]

Yes, the inline fuse protects the new relay. The original circuit has a 10 amp fuse, but we are creating a new circuit here too, so we need to add a new fuse. Others have picked up power at a different point, with other systems drawing on that circuit so a larger fuse may be needed for that method. I've had no problems with a 10 amp fuse on the newly created circuit as show in the drawing.

 

[pedalstomper78]

Guys, I wanted to give this thread a bump. I've had some starting problems with mine and I've replaced tons of stuff chasing my tail on this. I did all sorts of testing on batter voltage, the starter, etc.

Needless to day, I'll be installing a relay this morning....... So I figured I'd bump this so it's fresh in any new owner's mind.

Thanks!!!!!