MF 399 stop solenoid fault

mickdw

Im looking for info on wiring etc to stop solenoid at the diesel pump on MF 399. The tractor stopped suddenly and wouldnt start. Found that there was no power at the stop solenoid with ignition on. Found a blown fuse and now there is 12v coming with ignition to one of the 2 pins on the solenoid. Is there a 24v feed also needed to this solenoid or is the single 12v feed correct - I know some heavy machinery have a strong feed while starter is activated to actually pull the plunger in the solenoid then a lower powered feed to hold the plunger back.
Any info on tracing this fault or a wiring diagram would be appreciated. Tractor is running now with plunger removed but has to be manually stopped at the pump.

himwdah

fit a choke cable and be done with it.

or else check ur keyswitch as that happened ours, we fitted choke as keyswitch dropped power when turning engine, best job we done.

mickdw

So there is an additional supply when starter is turning?
And yes, fitting a manual stopper is a good option but its not my tractor so want to put it right.

himwdah

mickdw wrote: »

So there is an additional supply when starter is turning?
And yes, fitting a manual stopper is a good option but its not my tractor so want to put it right.

not sure of additional supply, guessed key was done as the next thing was it wouldnt heat her right but found that out in winter and electric stop went in summer, electric stop had 12v supply a little smoke at start then it died away as the engine turned, if that helps ur symptons.

mickdw

himwdah wrote: »

not sure of additional supply, guessed key was done as the next thing was it wouldnt heat her right but found that out in winter and electric stop went in summer, electric stop had 12v supply a little smoke at start then it died away as the engine turned, if that helps ur symptons.

Seeing as the 12v stays on for the tractor to run, if yours was smoking while turning over to start would suggest to me an additional current at that stage that switches off once started. i.e, a pull current and a hold current.
Hopefully someone here will be able to clarify.
One pin is now giving 12v and the other pin is going to earth but I guess that could change from earth to current flow if a relay is energised so that is why I would like some info on the wiring. I tried 12v direct and various earth combinations on the pins but its not pulling the plunger. Didnt want to stick 24v onto it if its not supposed to get 24v.

beretta686s

its only a 12v system 1 pin is live the other is earth,if u have 12 volts there now its probably just the solenoid they do give bother

mickdw

beretta686s wrote: »

its only a 12v system 1 pin is live the other is earth,if u have 12 volts there now its probably just the solenoid they do give bother

Thanks alot.

Are you 100% that its just the single 12v supply. If so, I will just order up a new solenoid.

marlyman

mickdw wrote: »

Thanks alot.

Are you 100% that its just the single 12v supply. If so, I will just order up a new solenoid.

100% deffo sure. There is a power drop fault on the loom of the 399. A rekay kit is available to solve this problem.

mickdw

marlyman wrote: »

100% deffo sure. There is a power drop fault on the loom of the 399. A rekay kit is available to solve this problem.

Can you explain more about this? Ive got 12v at the pump again so im good surely?

sandydan

My 1991 Mf 399 has a wiring problem New alternator same model as old one but Rev counter not working checked all connections at back of dash , battery charging fine ,light at side under panel is lighting though, suggestions appreciated

gctest50

mickdw wrote: »

Can you explain more about this? Ive got 12v at the pump again so im good surely?

Careful ! some stop solenoids are about 7 volt to get over the low voltage problem

If you order the wrong one and your yoke doesn't have the volt dropper device it will burn out your new solenoid



Stick a relay down near the solenoid if it is 12v and the loom has voltage loss issues

http://www.ebay.com/itm/waterproof-relay-and-connector-12-volt-fuel-pump-cooling-fan-Hi-temp-wire-/300900290202

Thelostcountry

What, Mr KNOW IT ALL told you about 24V system on a 399? FFS

You have 12V . you have a good earth? if You have a test light put it in series with the power supply connector. check the solenoid for continuity also.

Do not buyanything!!! until You can say, OH... THATS THE PROBLEM. i see lads all the time throwing money at yolks.

emaherx

sandydan wrote: »

My 1991 Mf 399 has a wiring problem New alternator same model as old one but Rev counter not working checked all connections at back of dash , battery charging fine ,light at side under panel is lighting though, suggestions appreciated

How many wires going into alternator? 3 or 4?
There should be 3 connected via a single block connector, these are for charging system. A 4th wire is then connected for the rev counter. the 4th wire may look like an earth strap but its not, it has to be connected to the special sense terminal not an earth point.

on a separate note I have seen these rev counters not working if the battery is in a low charge state (even charged well enough to start the engine), Stick the battery on charge over night and see if that helps. Alternator should charge the battery well enough in time.

sandydan

Sorry for crashing into your page Mickdw was not intentional had post sent before realizing it,I posted on separately after but it wasn't noticed.The MF 300 series are 12v, the only make i knew of combining 2x12v to produce 24v was zetor using a unit under seat for starting, if ever in doubt check batteries to see how they connect to starter or isolating switch for 12v or to each other for 24v

Thanks for reply emaherx, all wires are connected as you suggest, what i forgot to say was if tractor is started on run rev counter works ok, but not if key is used, stopping immediately and re-starting on run does not sort this problem it needs time charging, thought it seems like power going astray and overloading a circuit or connection in dash or key switch thanks for suggestions though.
any ideas about 4WD braking? thanks, sandyman

emaherx

sandydan wrote: »

Thanks for reply emaherx, all wires are connected as you suggest, what i forgot to say was if tractor is started on run rev counter works ok, but not if key is used, stopping immediately and re-starting on run does not sort this problem it needs time charging, thought it seems like power going astray and overloading a circuit or connection in dash or key switch thanks for suggestions though.
any ideas about 4WD braking? thanks, sandyman

Sounds like a bad alternator or battery is causing your issue. I've had 3 300 series Massey's and they all behaved this way when battery’s or alternators were on the way out. Have also had the issue with new spurious alternators.

sandydan

Thanks for help emaherx
i will put both batteries on charge on Mon for 24 hrs at least,was considering enlarging one battery case and fitting one heavy duty battery, did it previously on a 390 and alternator coped ok, also was considering replacing lamps with led lamps especially the tail lights if i can get ones that fit in existing slots, corrosion is a nuisance despite spraying regularly.