Zetor 3340 with new battery, keyswitch, solenoid & clean ground will not start!!

[tim_]

Zetor 3340 with new battery, keyswitch, solenoid & clean ground will not start!! When I began troubleshooting, charged battery, shattered brittle solenoid body loosening nut to check connection. Took starter to garage and they used a charger/starter (bypassing bad solenoid) and motor spun up -- that is when I bought a new solenoid and key switch. When all is connected, got the same result as what originally happened--dash lights go out and gauges go to zero. Next, disconnected all ground points, cleaned and added anti-oxidation grease. Same results again. thought maybe had a bad, intermittent battery cell so bought new battery. Same results. Disconnected and reconnected all connectors under dash to re-establish good connection. Same results. Tried running jumper cables direct to starter and the solenoid clicks, but starter motor does not run. Please help !!!

 

[big_orn]

Welcome to Zetorworld, Tim.

You say you connected straight to the starter motor - did you ground directly at the starter motor and apply power directly to the starter motor, bypassing all other connections?

 

[tim_]

Yes I did and took off all positives to isolate the starter. Also jumpered 12vdc to spade connector to activate solenoid.

 

[tim_]

By the way, thank you for the welcome and responding to my post!

 

[tim_]

I know it seems like the starter motor, but that defies the test at the garage using a charger/starter. Do they have enough amperage to drive a partially faulty starter motor? What am I missing here?

 

[big_orn]

It sounds like you still used the solenoid to apply power to the starter...right?
Even new solenoids can be bad.
Unless you connected to the field wire and bypassed the solenoid.

 

[tim_]

I tried both ways- going through the solenoid and direct to motor terminal just to see if the starter motor spun up.

 

[tim_]

It occurred to me that the new solenoid may be pulling the voltage to ground. Maybe I should take the connector off the solenoid and go direct to the starter. What do you think?

 

[big_orn]

It sounds like it's time for another bench test.
This time check the solenoid independent of the starter to see if the plunger is functioning correctly. This will ensure the contacts are working.
Then test the starter the same way the garage did.
This will diagnose and rule out or convict those two components.

 

[big_orn]

Sorry didn't see your previous post. Yes by all means test it that way.

 

[hala]

Have had about the same symtom on my 4340, with the same type of starter. My problem was stucked carbon brushes. By the way that starter eats solonoids. If one brush is stucked it feels like bad battery and with two its dead. In the beginning this problem comes and goes however will end up in total death.
Hazze

 

[tim_]

My problem is solved. It all came down to a good ground to the starter. I thought I was pretty thorough wire brushing all the contact points, but overlooked where the cable eye end is bolted to the lead terminal clamp. Additionally, Peter of Zetor Tech Support pointed out that my particular 3340 has a ground strap bolted to the transmission and may need some bolts that connect the trans to engine loosened and re-tightend to re-establish a ground. One other thing noted by Peter is that jumper cables do not have a large enough gauge wire to transmit the 200-300 amps needed by these starters causing you o draw false conclusions.

 

[big_orn]

Good deal! Glad you got it figured out!