New Holland TC29D Starting Issues

stevegay · Nov 8, 2020

I have a 2003 New Holland TC29D that will only start if I boost it off or bypass the ignition switch and connect the start solenoid directly to the battery. The starter/solenoid, battery, and key switch are all new. I used another battery (instead of the new one) just in case the new battery was bad and it still wont crank. I have swapped relays 1, 2, & 3 around, cleaned the terminal strip where the relays connect, and nothing helps. After boosting it off, it will crank one or two times after disconnected from the boost battery but if it sets for a few minutes, it wont crank. I can hear the start solenoid hitting, but it wont engage the starter motor except under the conditions described earlier. I have also cleaned the connection where the negative batter cable is bolted to the frame. Any help would be greatly appreciated.

LS Tractor Owner · Nov 8, 2020

Check your ground cables. Clean off any paint or corrosion at all ground points. If that doesn't help, try running another ground cable. That's where I would start.....

LS Tractor Owner · Nov 8, 2020

Next, try an amp / volt meter on the battery while attempting to crank it... if the voltage drops below 12 and it won't crank, a battery / cable problem.

dlctcg · Nov 8, 2020

I agree with the above on checking & cleaning the battery terminals, connectors & grounds, but being it seems you've done that....

Older New Holland battery cables often corrode inside the terminal where it is sometimes impossible to see; not sure it was an issue with your particular yr / model... You will often have voltage so everything seems good. (gauges & all are working).

You can test if there is an issue with your existing battery cables pretty simply.

Remove the negative battery cable & then take a negative jumper cable wire and place it on the bare negative post of your tractor battery. Connect the other end to a solid clean ground of the tractor (bare metal location). Try starting the tractor & see if that makes a difference...

If that doesn't change anything you can do the same process on the positive post. Disconnect the Negative jumper from the Battery terminal. Then using your positive jumper cable attach one end to where the positive battery cable connects to the starter (connect this end first), and the other end to the positive battery post (last). Make sure the jumper cable is not able to arc to near by metal. Now reconnect the Negative jumper cable to the battery & try starting the tractor again & see if that changes anything...

Doing this process you basically bypassed the battery cables on the machine, and then can troubleshoot from there. I wouldn't put any more parts on it till I checked the factory cables...

stevegay · Nov 8, 2020

Thanks for the info. I'll try that next. I made a typo in the original post. Its a 2003 model, not 2013. The starter motor (original) and battery (5 years old) bench tested bad so they needed to be replaced so the only thing I may not have needed was the aftermarket key switch and it was only $12.

WM75Guy · Nov 8, 2020

Like the others said the factory cables have a bad habit of internal corrosion. I had to replace mine on the TC40DA. They will allow voltage to go across but not amperage under load. You put a meter on them and volts looks good. I have a DC amp clamp so I could see nothing was being allowed to pass when I hit the key to start it. Without a DC amp clamp using the jumper cables is an easy way to test to see if the cables are the problem. I got new cables from the auto parts house, cheaper than NH factory cables.

stevegay · Nov 9, 2020

I used jumper cables to effectively replace the factory battery cables as you described and it still doesn't crank. It seems I have a bad ground on the 12V supply circuit to the solenoid. It gets its ground by contact with the frame where the starter mounts. Next, I will connect a wire from the case of the solenoid directly to the negative terminal of the batter and see if that helps

stevegay · Nov 27, 2020

I have found the problem. The lamp timer circuit shares a voltage source with the start solenoid. With wire HM17 (supply voltage to the start solenoid) connected, I'm only getting 5V to the solenoid. I get 10V with HM17 disconnected. I get the same voltages when tested at the start relay. The manual says that the lamp timer only controls the glow plug indicator lamp on the dash, but I think it supplies voltage to the glow plugs as well. With the lamp timer disconnected I get 12V to the solenoid, the starter will engage, and the engine will turn over fine, but it just won't crank. Occasionally, the tractor will crank after reconnecting the lamp timer.

dlctcg · Nov 27, 2020

You can modify the current wiring & add a dedicated relay for supplying direct power to the starter solenoid via the same circuits. I did this on our TC40D & it made a big difference for our machine.

There is a write-up on TBN about it & I think I might have saved the PDF diagram on how to do it, I can look for it if you are interested. Basically over time the connections get dirty, contact corrode, ect & there winds up being to much resistance in the circuit to provide full voltage to the solenoid . Adding the dedicated relay eliminates that issue while keeping all other functions of the circuit intact.

This is a pic of the relay I added: