YM 1820 Mystery electrical box

[pycoed]

I've just picked up a really nice little YM1820(see below) with the usual tractor wiring issues - I suspect connections behind the fusebox would be the main culprit. Ignition switch partly works but previous owner had bodged two wires to be joined under the the bonnet (hood!) to start her up. As a temp measure I've further bodged these into a push switch that at least you can reach from the wheel! She's an INSTANT starter.
Anyway I'm doubly mystified: firstly by the Japanese wiring diagram I found online, but I suppose I can get around that ... but I have small metal box on the rhs of the bulkhead labelled HITACHI W11-07. It's just a little smaller then the regulator on the other side of the bulkhead, but with a smooth steel case. Three wires are connected into it, Red, Yellow & Black medium diameter so no significant current carried I suppose. Does anyone have any ideas what it does?

 

[ponytug]

@pycoed Congratulations on the new, to you, purchase!

I guess I have three questions;
1) can you post a picture of the Hitachi part?
2) have you tried a google image search on the photo of the part?
3)given that the prior owner bodged a few things together, did you check where the item is connected to?

My bet would be that it is, in fact, the voltage regulator. Hitachi made a variety of them for older tractors and cars.

On older vehicles/tractors where the previous owners have mucked about with the wiring, I'm generally inclined to set aside time and just rewire. It gives the tractor fresh connectors, insulation, and, for my work, often a chance to upgrade the wire quality and gauge. I tend to use marine grade wire and waterproof connectors. I find that it saves me effort in the long run, as I end up touching every connection, switch, and sensor. For me, I find it rather satisfying work, but I know that isn't the case for everyone. Given the climate where you live, I personally would be inclined to be generous with dielectric grease and protection sprays.

All the best,

Peter

 

[winston1]

I

I've just picked up a really nice little YM1820(see below) with the usual tractor wiring issues - I suspect connections behind the fusebox would be the main culprit. Ignition switch partly works but previous owner had bodged two wires to be joined under the the bonnet (hood!) to start her up. As a temp measure I've further bodged these into a push switch that at least you can reach from the wheel! She's an INSTANT starter.
Anyway I'm doubly mystified: firstly by the Japanese wiring diagram I found online, but I suppose I can get around that ... but I have small metal box on the rhs of the bulkhead labelled HITACHI W11-07. It's just a little smaller then the regulator on the other side of the bulkhead, but with a smooth steel case. Three wires are connected into it, Red, Yellow & Black medium diameter so no significant current carried I suppose. Does anyone have any ideas what it does?
View attachment 883401

I suspect it controls the thermostart. My old 2002D had one.

 

[careyo63]

My 2000 setup! The box behind the Solid state is the Org. V. Reg.. I use a Alternator similar. Your Alternator should be a AL-1215 12V-15Amp. I use a AL-1220 that looks the same but is wired different. My guess is the Mystery box is the Org. Regulator. Not a Solid State. I'm showing a Solid State Voltage Reg. for a 1820 should be a VR-522 6plug. And being Org. the mystery box maybe a Regulator and needed a Adapter WH-522 4 plug adapter . Fredricks Equipment is clearly showing it so I'm sure they can tell you more about it and a possible upgrade made?.

Attachments

• 
  000_0222.JPG

  2.5 MB · Views: 559

 

[pycoed]

@pycoed Congratulations on the new, to you, purchase!

I guess I have three questions;
1) can you post a picture of the Hitachi part?
2) have you tried a google image search on the photo of the part?
3)given that the prior owner bodged a few things together, did you check where the item is connected to?

My bet would be that it is, in fact, the voltage regulator. Hitachi made a variety of them for older tractors and cars.

On older vehicles/tractors where the previous owners have mucked about with the wiring, I'm generally inclined to set aside time and just rewire. It gives the tractor fresh connectors, insulation, and, for my work, often a chance to upgrade the wire quality and gauge. I tend to use marine grade wire and waterproof connectors. I find that it saves me effort in the long run, as I end up touching every connection, switch, and sensor. For me, I find it rather satisfying work, but I know that isn't the case for everyone. Given the climate where you live, I personally would be inclined to be generous with dielectric grease and protection sprays.

All the best,

Peter

Yeah I know what you mean - my first tractor an UTB 445DT (sold in US as a Long 445) needed a complete rewire since just about every cable was rotted. I've found the former Soviet bloc countries couldn't do plastics at all well - ever felt the interior panels in a Yugo or Lada? Ugghhh!
Ditto with my Zetor - which has a LOT of wiring: lights, flashers, heater wipers washers trailer sockets etc etc. Took a LOT of work to get everything working on that - climbing up stepladders to get at the work lights & heater blowers was fun!
However this one is very good generally - cables all have kept their colour & flex well & all seem in place except the solenoid starter connection. Also no sign of bodgery behind the dash. Original starter connection had been disconneced & a jumper pair connected from the + terminal & solenoid & left loose under the bonnet. Touching the two ends together started her up. Apart from that, the wiring looks original & in good shape.
Horn & turn indicators work - all guages but no headlamps, & this start issue. I'll work through it slowly over the next couple of days but wife's car needs an MOT test next week so that'll take precedence (you know how it goes...?)

 

[pycoed]

I suspect it controls the thermostart. My old 2002D had one.

Looks exactly like it - I'll post some pics today. I wonder what it might do for the thermostart? Sense temperature & inhibit operation unless below 0 Celsius? I'd be surprised if I ever needed the thermostart this little engine is such a good starter & our temps never get much below 5 Celsius here ( absolute coldest ever here was down to -15 but most winters only a week or so of sub zero)

 

[pycoed]

My 2000 setup! The box behind the Solid state is the Org. V. Reg.. I use a Alternator similar. Your Alternator should be a AL-1215 12V-15Amp. I use a AL-1220 that looks the same but is wired different. My guess is the Mystery box is the Org. Regulator. Not a Solid State. I'm showing a Solid State Voltage Reg. for a 1820 should be a VR-522 6plug. And being Org. the mystery box maybe a Regulator and needed a Adapter WH-522 4 plug adapter . Fredricks Equipment is clearly showing it so I'm sure they can tell you more about it and a possible upgrade made?.

Attachments

• 
  000_0222.JPG

  2.5 MB · Views: 559

My regulator has the six plug & all looks original there & with the alternator too.

 

[pycoed]

Fredericks Equipment looks a very useful reference site too, though I expect the shipping costs would kill any order possibility. Luckily most engine parts are easy over here since Yanmar engines were widely used in diggers & dumpers as well as the compact tractors

 

[winston1]

Looks exactly like it - I'll post some pics today. I wonder what it might do for the thermostart? Sense temperature & inhibit operation unless below 0 Celsius? I'd be surprised if I ever needed the thermostart this little engine is such a good starter & our temps never get much below 5 Celsius here ( absolute coldest ever here was down to -15 but most winters only a week or so of sub zero)

When turning the key to the left for activating the themostart the red light on the dash would come on indicating the themostart was working. The little box then automatically turned off the thermostart and red light. Just how is did that is a mystery to me.

 

[careyo63]

Ghetto Rigged on his Ign. Switched

 

[pycoed]

Just taken a couple of pics of the mystery box.(See below) I thought I'd cracked it today by removing & cleaning all the connections on the fuse box & fuses even though they all looked fine (I hate glass fuses, but at least they are better than the old Euro fuzes with exposed fuse links, though give me a blade fuse any day). Voila - all the lights worked correctly!
Then I thought I'd check the clutch safety switch - this as far as I know is the only start-inhibiting switch on this model - I don't think it has the neutral & PTO netral switches as well. I found that the clutch pedal wasn't pushing it far enough make contact. Adjusted it's position, clamped the clutch down & still no signal at the original starter solenoid connection when turning the key (switch is fine). So I started to trace the wires (2 black) from the start terminal on the switch... one of the wires is the black wire which runs into the mystery box! Haven't traced the other yet, but it doesn't connect directly to the clutch switch as I'd expected.
Very interesting to read the magic box may control the thermostart, acting as a timer... I get the red dash light coming on when turning the key back but I haven't checked this box to feel if it starts to buzz or anything. I'll have to leave it for a day or so while I sort the missus' car, but I'll post back when I get some progress...

 

[careyo63]

Turn your key backwards and it puts power to the Thermal start! On the YM2000. The 1820 isn't showing how they done it or what Thermal start setup they used.

Attachments

• 
  003 (2).jpg

  499.8 KB · Views: 222

It should be pretty much the same. I don't use it and don't have the fuel cup hooked up! Put fuel to it and it works AIS..

 

[ponytug]

Just taken a couple of pics of the mystery box.(See below) I thought I'd cracked it today by removing & cleaning all the connections on the fuse box & fuses even though they all looked fine (I hate glass fuses, but at least they are better than the old Euro fuzes with exposed fuse links, though give me a blade fuse any day). Voila - all the lights worked correctly!
Then I thought I'd check the clutch safety switch - this as far as I know is the only start-inhibiting switch on this model - I don't think it has the neutral & PTO netral switches as well. I found that the clutch pedal wasn't pushing it far enough make contact. Adjusted it's position, clamped the clutch down & still no signal at the original starter solenoid connection when turning the key (switch is fine). So I started to trace the wires (2 black) from the start terminal on the switch... one of the wires is the black wire which runs into the mystery box! Haven't traced the other yet, but it doesn't connect directly to the clutch switch as I'd expected.
Very interesting to read the magic box may control the thermostart, acting as a timer... I get the red dash light coming on when turning the key back but I haven't checked this box to feel if it starts to buzz or anything. I'll have to leave it for a day or so while I sort the missus' car, but I'll post back when I get some progress...
View attachment 883500View attachment 883501

I'm glad that the wiring is mostly ok.
You might want to look at a YouTube video of the thermostart.
Quick:

Longer:

(Skip to the almost the end to see the ignition.
Basically, a coil gets red hot, the heat opens a valve to dribble in some diesel fuel that ignites and burns, warming the intake manifold. When the ignition switch moves from preheat to start, voltage to the thermostart goes off. I believe that the box has a relay and timer to prevent the thermostart from being on too long. As you can tell, it would not do anything very productive to be on while cranking, unlike glow plugs or electric intake heaters.

Good luck on the MOT testing.

All the best,

Peter

 

[pycoed]

I've just found a wiring diagram for a YM 2420 that seems to have this box in the circuits (it's a lot clearer than the one for the 1820).It seems to connec to the little red light & what might be the thermostart. Does anyone have a wiring diagram in English for this model they could post ?

 

[bmaverick]

I've just found a wiring diagram for a YM2420 that seems to have this box in the circuits (it's a lot clearer than the one for the 1820).It seems to connec to the little red light & what might be the thermostart. Does anyone have a wiring diagram in English for this model they could post ?

You need this doc off of the YTOG. Our team put this together just for the reason of using it as a deciphering tool for the Gray Market machines to compare the English model schematics to the Japan ones.

YANMAR ELECTRICAL SCHEMATICS YM 3-DIGIT MODELS R3.pdf

Here are some examples towards a YM1802

YM1802 Headlamp to switch

YM226 Headlamp to switch that matches

 

[pycoed]

I'm glad that the wiring is mostly ok.
You might want to look at a YouTube video of the thermostart.
Quick:

Longer:

(Skip to the almost the end to see the ignition.
Basically, a coil gets red hot, the heat opens a valve to dribble in some diesel fuel that ignites and burns, warming the intake manifold. When the ignition switch moves from preheat to start, voltage to the thermostart goes off. I believe that the box has a relay and timer to prevent the thermostart from being on too long. As you can tell, it would not do anything very productive to be on while cranking, unlike glow plugs or electric intake heaters.

Good luck on the MOT testing.

All the best,

Peter

Yeah _ I know about Thermostarts - I had one on a UTB 445DT & still have a new one in it's box in my garage (was the wiring to the thing was dead on the UTB, not the TS)

You need this doc off of the YTOG. Our team put this together just for the reason of using it as a deciphering tool for the Gray Market machines to compare the English model schematics to the Japan ones.

YANMAR ELECTRICAL SCHEMATICS YM 3-DIGIT MODELS R3.pdf

Here are some examples towards a YM1802

YM1802 Headlamp to switch
View attachment 883566

YM226 Headlamp to switch that matches
View attachment 883567

I'll have a look for that - thanks!

 

[pycoed]

I'll have a look for that - thanks!

The search on the YTOG doesn't return any file found for that & I couldn't find it in the Resources section either - any direct link available? TIA

 

[California]

I see Wi1-07 in your photo. Searching that # online one guy says it is the turn signal flasher on a Yanmar, in an old TBN thread. But there's no additional detail in that thread.

A post on a boating site says Wi1-05 is the engine alarm, for low oil pressure etc.

https://www.sailnet.com/threads/engine-alarm-buzzer.24298/

your buzzer model is WI1-05. Its one input and 3 output (negative as return) via 3 diodes. If the other two alarm works, then its probable the 3rd diode is faulty. You could wire two diodes to one of the working output thus making it as 2 circuit. That should solve your problem. When activated, the positive passes through the buzzer diode, then through to 1 of the new diodes to say Oil Pressure switch or Sail Drive Unit switch then to ground (negative). The buzzer maybe just alittle softer as there'll be 1.2V drop across the series diodes but I guess it won't affect much. The Hitachi buzzer doesn't come cheap. [$150+ in 2006]

I didn't research this any farther but searching "Hitachi Wi (letter i, not numeral 1) 1-0" should find more information.

If it is either a turn signal flasher, or a boating dashboard alarm, it doesn't sound essential so long as you have oil pressure and temp gauges or idiot lights.

​

 

[pycoed]

I've realised that it is in fact WI1-07 rather than W11- I found an old post from Winston back in 2012 that described it & it is in fact a timer for the thermostart as he suggested, fair does!
I tried holding the key in the TS position today & the red TS indicator light goes off after about 20 secs.
Thanks for looking - I should have seen that - I blame failing eyesight after 74 years of abusing it!
I now know this box is working, & all I have left to trace is why the ignition switch doesn't seem to send a signal to the solenoid in the Start position - I think I need to prove the wires from solenoid to clutch switch & clutch switch to ignition. I'm beginning to suspect mousie may have been nibbling somewhere along the line , though to be fair, the loom & the whole tractor is in VG condition for its age, which is why this little problem is nagging at me

 

[ponytug]

I've realised that it is in fact WI1-07 rather than W11- I found an old post from Winston back in 2012 that described it & it is in fact a timer for the thermostart as he suggested, fair does!
I tried holding the key in the TS position today & the red TS indicator light goes off after about 20 secs.
Thanks for looking - I should have seen that - I blame failing eyesight after 74 years of abusing it!
I now know this box is working, & all I have left to trace is why the ignition switch doesn't seem to send a signal to the solenoid in the Start position - I think I need to prove the wires from solenoid to clutch switch & clutch switch to ignition. I'm beginning to suspect mousie may have been nibbling somewhere along the line , though to be fair, the loom & the whole tractor is in VG condition for its age, which is why this little problem is nagging at me

It is very easy for one or two poor connections to reduce the voltage from the switch to the starter solenoid to the point where the solenoid doesn't function. I've sprayed carb cleaner through starter switch keyholes more than once. I usually follow it up with some DeOxIt as a contact cleaner, and general purpose anti corrosion spray. I use DeOxIt on connectors routinely. I suspect wet West Wales is a challenging environment for wiring harnesses...

All the best,

Peter