Intermittent Starting problem - sometimes starts,sometimes solenoid just clicks

[Marrow999]

A UK based newbie to this fabulous forum so be gentle! This issue is getting me down!
So, starting a Jinma 254......
As in the title she turns over no problem sometimes, but the next time just solenoid click....regardless of temp (ie starting from cold or from warm)
Have replaced the starter motor - bridging the two large terminals on the new motor and she spins freely, bridging to the smaller terminal and the + she engages and turns over no problem (NB tractor in neutral!!). Battery is fine (have had it professionally tested). Have linked out the clutch switch. Have set jumper lead from battery negative directly onto start mounting bolt. Have found suspect cable (white) coming into the connector block near the fuse panel so have cut/linked across the block. Next job is to cable directly from terminal 4 on the ign sw to the small terminal on the solenoid to see if that works.
Gut feel is that the solenoid is not quite closing strongly enough perhaps due to voltage loss? What is the best way to investigate this theory? (have multimeter....)
Am determined to get to the bottom of this so am starting this thread as a resource for those with similar intermittent issues (can't see this being covered elsewhere on the forum with a solution?)

 

[Bob Rooks]

I see this is only your second post, so :welcome: :welcome:

With your meter on the 3 volt DC scale connect one lead to the negative battery terminal and the other lead to a good clean chassis ground. Crank the engine normally and observe the reading. It should read zero to 0.01 volts. Any more than that and you have a grounding issue. You could also have a serious voltage drop through the key switch (there is no ignition system). Both of those scenarios are common to these tractors. Another thing which you mentioned is the starter solenoid itself - was that also replaced along with the starter?

 

[flyerdan]

Take the solenoid apart. The bakelite cap on the end should have two square head copper bolts that the battery cable attaches to on the outside, and inside is where the plunger bridges them to supply full current. Often the heads will erode and carbon up from arcing. Carefully tap the bolts out, burnish everything up on a wire wheel and reinstall the bolts so the new part of the head is facing inward. Put everything back together and enjoy new starter performance.

 

[BertZegers]

I see this is only your second post, so :welcome: :welcome:

With your meter on the 3 volt DC scale connect one lead to the negative battery terminal and the other lead to a good clean chassis ground. Crank the engine normally and observe the reading. It should read zero to 0.01 volts. Any more than that and you have a grounding issue. You could also have a serious voltage drop through the key switch (there is no ignition system). Both of those scenarios are common to these tractors. Another thing which you mentioned is the starter solenoid itself - was that also replaced along with the starter?

I would like to ad; put the probe on the battery negative post, not on the clamp. A bad contact between battery post and clamp is very common, check both positive and negative battery connections.

 

[Marrow999]

Hi Bob
Thank you so much for you detailed response. I will recheck the grounding and let you know. Solenoid was indeed replaced with the starter. Have ordered a replacement switch (of course you are right - not an ign switch as such!).
Will update you - thanks again.
Mark

 

[Marrow999]

Hi Dan - one for the future I think - the solenoid was replaced with the starter motor so very new!

 

[Marrow999]

I would like to ad; put the probe on the battery negative post, not on the clamp. A bad contact between battery post and clamp is very common, check both positive and negative battery connections.

Thanks Bert - wise comments indeed.

 

[jacques54]

On those JIMMA some owners have installed a BOSCH relay close to the starter. It save a lot of wear on the key switch, known to be the common culprit of starting issue on these tractors.
Plus those relays are cheap and reliable.
Jacques

 

[Marrow999]

On those JIMMA some owners have installed a BOSCH relay close to the starter. It save a lot of wear on the key switch, known to be the common culprit of starting issue on these tractors.
Plus those relays are cheap and reliable.
Jacques

Hi Jacques - yes I have heard that as an option and am probably heading that way. Am at my deskjob currently but will be running through the other great suggestions as well. Brilliant help all round!

 

[RonMar]

well if it starts every time jumping the small terminal, sounds like you have a starter circuit or start switch issue. there is a multi-pin connector above the fuel tank that can be a source of issues for this and for the glow plug circuit...