question Repairing my Zetor 6945

[Vikafarm]

Just got hold of a 6945 for use on my small holding, it needs a new clutch which I'll have a workshop do but there's some electrical issues that I want to fix myself.
Therefore I could use a good wiring diagram if anyone has one as what's under the bonnet is unreadable and the workshop manual isn't great.

The biggest electrical issues are it's not charging, so maybe a regulator or a bad wire, and the start button doesn't work. Also possible a bad wire.
At the moment the only way to get her going is jumping the starter solenoid with a screwdriver and keeping the battery on charge when not in use.

If anyone could help is be grateful.

 

[Vikafarm]

To add there's a small connector loose next to the starter, I can't see anywhere it should attach, does anyone have any suggestions.

 

[Joachim]

This is a wiring diagram from a 4712 - should be the same as you need:

The biggest electrical issues are it's not charging, so maybe a regulator or a bad wire, and the start button doesn't work. Also possible a bad wire.
At the moment the only way to get her going is jumping the starter solenoid with a screwdriver and keeping the battery on charge when not in use.

Check the start magnet and the small cable at - it should have 12V when you press the start button. If there is 12V, then check the battery cable for 12V and corrosion at contacts.

 

[moliner]

To add there's a small connector loose next to the starter, I can't see anywhere it should attach, does anyone have any suggestions.

Could that small connector be for the oil pressure sensor? It located in the engine block, right above the starter motor.

 

[Joachim]

Not realy in this series - or Iam wrong? But I think electrical sensor came first time with series 10 (5011 to 7045) or not?

 

[Vikafarm]

Its at a workshop having the clutch replaced, its probably something simple but I need to have a good look at so see what goes where.
The contacts on the battery are fine so my guess a bad wire or regulator causing the lack of charge.

Does anyone have a good source for the window rubber seals? They're all heavily perished and need to be replaced.

 

[moliner]

Not realy in this series - or Iam wrong? But I think electrical sensor came first time with series 10 (5011 to 7045) or not?

I have one in my 3511, so they have been electrical for a long time

 

[Joachim]

Correct - my fault.

 

[Vikafarm]

Couldn't see it when I looked earlier today, could someone post a picture of the temp sensor location, maybe someone put a bolt in it's location instead

 

[moliner]

Not sure about your model, but I found this from a 6945 on YouTube.
Oil pressure sensor/switch marked with red arrow.

 

[Joachim]

could someone post a picture of the temp sensor location

 

[Vikafarm]

This is the connector in question, it's a little shot to go on the block if the main loom is in the right place. No obvious place for a sensor to go other than the weird bolg behind the starter.

 

[moliner]

View attachment 1085
This is the connector in question, it's a little shot to go on the block if the main loom is in the right place. No obvious place for a sensor to go other than the weird bolg behind the starter.

Did you try to find the other end of that cable?

 

[Vikafarm]

Its at a workshop having the clutch repaired so it wasn't the ideal place to go hunting it down. I'll be looking at all the electric once I get it home as there's multiple electric issues I need to fix but as I live down a steep hill I need the clutch sorted first

 

[Vikafarm]

I finally have the tractor back after the slowest clutch replacement in history. I had a look at the old one and the was nothing left so very happy I've had it done.
Now to try and fix it, as best I can before winter comes. First on the list is the start button. Looking at the wiring diagram it should connect to position 54 on the key. There's a similar colour wire on there and to the start button, I can't see it connects directly. Then a brown wire that I've not tracked where it goes, I assume the starter.

I'm not reading any power on 54 no matter which position the key is in. I assume this isn't correct but could someone confirm this?

 

[Joachim]

I hope that can help : Wiring diagram from Zetor 4911 to 6945

... but also to find in your spar parts book for this tractor model.
EDIT: mäh ... I posted it some days ago first time and now socond time

But it can also be a litle bit different like the older one 6745 it have:

 

[Vikafarm]

Thanks Joachim, it should have some power from the key right? I can measure it 12v on several terminals just not the one for the start button. A new ignition isn't much at least

 

[Vikafarm]

I had s look again, no power from point 54, even with the clutch down. Could someone give me the break down of the ignition sequence. I assume there's a cable that goes from the ignition to the clutch and back, then over to the start button. From there down to the start motor??

 

[Vikafarm]

Little update, I had the key in the wrong position as it needs to be position 0 (new tractor to me). Power on the ignition key terminal 54, but then the cable goes down under the floor. I assume to a switch on the clutch as the book stays it needs to be down to start. Can't see anything clearly under so I'll just run a cable from the ignition to the start button and bypass the clutch. Nice and simple.

 

[Joachim]

Sounds you realy need a instructions book for your Zetor 6945:

FAQ - Manuals for Zetor tractors

Due to the legal situation with the provision of operating instructions for Zetor tractors, there is "only" a link here, but to the official Zetor website. There you will find most of the operating instructions that exist for Zetor tractors and in many languages as well. So click on the...

zetorworld.com

It's possible that someone has retrofitted the safety switch on the clutch pedal. In itself, this is a very good thing. Newer Zetors have this fitted as standard.
It's supposed to prevent you from starting and possibly running someone over while the gear is still engaged.

 

[Vikafarm]

I dont have issue with that it sounds good but I can see enough under the cab. I'll leave the orginal cables in place and mark them, so when I get time next year i can see if I can get to the bottom of things

 

[Vikafarm]

I'll post here rather than starting something new, the fans for the heating need replacing. This is done from inside or by taking the roof off?

 

[Joachim]

You can lift up the cab roof in front of cab a litle bit, that makes it easier to change them.

 

[Vikafarm]

Perfect thank you so much, do you have any idea what the part number for the grill cover for them? I have one but am missing the other. I´ve found part ZE 59117807 but it doesn't match the one I have.

 

[Vikafarm]

So next thing to fix is the alternator. From the look of the electrics throughout the tractor I'm pretty sure a monkey has been doing the wiring . I don't think it was connected properly before but the previous alternator is heavily corroded.
I've got a new one with an in-built regulator. There's a b+ and b- which are straightforward.
I have two wires unconnected at the moment a red and grey. The red is reading around 10v without the tractor running and the grey isn't reading anything. I'm guessing the grey is for the D+ (I've not check this goes to the light on the dash) but does that sound right?
Currently there's D+ and W terminals on the new alternator.
Also where would I find the regulator if it's not been previously removed?

Attached photos are of the old alternator and the terminals of the new one.

 

[Joachim]

OK, thats not the original one alternator

I'm guessing the grey is for the D+ (I've not check this goes to the light on the dash) but does that sound right?
Currently there's D+ and W terminals on the new alternator.

Take a look at this Zetor FAQ entry:

FAQ - Alternator, regulator and co - Zetor and ZTS

Alternator, regulator and Co Caution - never let the engine run with the ignition key removed or the battery disconnected. There is a risk that the diodes in the rectifier of the three-phase alternator will break and thus destroy the rectifier. Design and structure of an alternator on a Zetor...

zetorworld.com

Also where would I find the regulator if it's not been previously removed?

The new one is mounted there:


The original old one was mounted just betwen alternator/starter and your ignition/starting switch - if its not removed previously.
I think it was mounted above the starter on the Zetor 6911/6945, and in later models it was mounted in the cab below the dashboard.