Hitachi EX60 URG need electrical diagram

[David gladwyn]

Hi Back again,
Ex60 wont start on the key now... has been an intermittent problem for a while and then stopped completely so thought it was the pre starter safety solenoid so replaced the switch part as I cant find a complete unit with the electronic part and still no good I'm guessing its the electronic part as I've tested the 4 pins 1 Earth 2 ignition live and 3 switch live from key. not sure about pin 4 guess it comes live when it starts. (forgot to test) Any ideas on the fault or where I can get a new unit or would it be okay to drive the solenoid direct from pin 3 or would I need to put a relay in? thanks Dave

 

[007]

Hi Dave,
I would not drive the solenoid on the starter direct from the key if it was me.
Since you have not posted a picture all i have to go on is that earlier posted circuit diagram which has 5 wires on the safety relay.
So you have to tell me what your numbers are represented on the diagram and why a missing wire??.
Is this relay mounted directly on the starter?
Have you have checked that your ignition switch is sending out 24v in the start position and appearing at the safety relay on pin S (BW wire)??
The start position only sends power to that relay and a glow plug timer from what i can see.
If you can solder i can tell you how to modify the existing relay to remove the electronics or you can just go and buy a standard $10 relay and retrofit it.
Off course it will be just like any car, if your dumb and turn the key to the start position when running you will get a grinding noise from starter.
Do you hear any clicking noise when you try to start at the safety relay or the solenoid on the starter??.
The way you are describing the wires is very confusing.
You should only have power appearing at pin B when the key is turned on.
Power appears at pin S when you turn your key to the start position.
If the engine is not running power is passed trough the relay and appears at pin C and continues through the loom to energize the starter solenoid.
When the engine starts approx 24V will appear at pin R.
Pin E is earth or machine frame.
Use a small bulb or a multi meter to test each step.
Get someone to turn the key for you so you can listen for safety relay clicking or starter solenoid clicking.
Another thing worth checking is your fuses as they can become intermittent cause they can have hairline cracks in them.
That diagram could be a simplified diagram because i see very few wires on the fuse box but they are indicating current draw across the top of ignition switch on each circuit.
Shows a 10A on start circuit so may be corresponding 10A fuse??

Regards.

 

[chiefCW2]

This thread is good. I have a ex60 with charging and starting trouble. For over 3 years the customer would unhook a battery cable because it wouldn't charge the battery. Now he wants to fix it. I replaced the alt with a aftermarket one that was 300.00 cheaper than a John Deere. It only charges at 25 volts and Batts wont stay charged. Nothing electrical worked before. No running lights no idiot lights. So no charging idiot light ether. We put two good battery's and it started but want start again untill you unhooked a battery cable. We here a clunk when we take the ground off. Then I put a cleaned ground back on then it started but won't start untill unhooking ground again. I thank it is the safety solenoid that stops the starter from working when engine is running. There are three inside the door on the Right side. Which one is the starter safety solenoid.

 

[007]

Hi chiefcw2,
You might have to get someone to help you to find the clicking safety relay.
Just a note:
25V is probably not charging at all but just the standing voltage of the batterys.
Looking for around 28V.
You need to do some quick checks as you might burn out that new alternator you have fitted.
I know this is going to sound strange but an alternator MUST have a load and if it output is open circuit from the battery it overheats internally.
Your machine has a solenoid which does just that and isolates the alternator from the battery with the key off.
For that alternator to operate battery voltage must appear on its output terminal when you turn the key on.
Also some voltage (can vary) must appear on the LY wire.
This is provided by a resistor from the output terminal and some from the warning light so is not full 24V.
This trickle of a voltage is used by the alternator to excite its self and get up and away charging when the engine starts.
Your starting problem is almost certainly the start safety relay is faulty or wired wrong causing it to think the engine is running.
Good Luck.

 

[chiefCW2]

Mr 007, I was glad you saw this. Can you tell me in the batt. Compartment on the right side, from top to bottom what the name. Of each solenoid and a short definition. I am not sure which one is safety solenoid. I can fill the one in the middle click when the key is turned on. And I can fill it when I take the negative cable off it's terminal. Otherwise it won't start two times in a row if I don't take the cable off.
Does John Deere have the solenoid and how much are they?

 

[007]

No Clue never seen your machine before.
Maybe someone with a manual might save the day for us.
The wire color code in the posted diagram would be a clue also.
a lot of machines have the safety relay mounted out on the side of the starter solenoid.
You could post some pics, you never know i might see some thing that might help.
If your machine is as per that diagram there should be only the battery relay in the top left corner being energized when you turn the key to the on position.
no other relay should click unless you crank the engine or the engine starts
The cost of what? you keep saying solenoid for some reason.
If you mean Safety starter relay I read a thread where the guy said a new starter safety relay was $150 i think.
I personally would be fitting a $5 dollar relay and losing that other starter inhibit feature.
If you mean Battery Relay it will be a fare size item with large cables attached and prob cost will be eye watering if you went genuine.
I don't believe it has any issues as the engine would not start if that was not closing.
Can you confirm its the relay with the large cables on it that is clicking with the key on please.

 

[chiefCW2]

I call it a solenoid because they look like a solenoid to me. Your right on the battery relay it is larger than the other two relays and all three are on the right side of the battery compartment.
I can fill the battery relay click, when the switch key turned on. But it don't click again when the key is turned off. It looks to me it's the safety relay like you said I don't know how to identify the safety relay.

 

[007]

Thats interesting thanks.
Based on what you have said odds are there is nothing wrong with the relays.
The starter saftey relay and the load damp relay both monitor the alternator light circuit to determine if it is spinning.
If it is spinning there will be a voltage present there which in the case of the safety relay stops you engaging the starter and in the case of the load damp relay it turns on and locks on the battery relay which is not disabling when you turn the key off.
This means both relays are doing as they should.
This means ether the alternator is faulty, or has been wired wrong, or someone has done some wiring changes and some how has ignition being applied to that circuit.
That circuit is what they call a latching circuit because once enabled it locks on until the engine stops.
Now you know where the battery relay is follow the small wires from it to find the load damp relay.
The diagram indicates a terminal with two small wires connected, maybe green colour.
One goes to the ignition and the other the load damp relay.
Then you have two out of three relays identified.
If you find the load damp relay and find terminal 1 and see if 24v appears there when you turn the key on.
If it is there then thats a problem and you have to find out where its coming from.

 

[chiefCW2]

Mr 007,
Thanks for your help with the ex 60 it is 30 miles away and I have been adding to my barn so I haven't been back to the machine. I will print your information off so I can follow it.
I was in Perth and Fremantle in 1982& 1983 I loved those cities. I was a Marine on a Navy ship. I met a young lady and wanted to stay but my Gunny wouldn't let me. I did have a friend that met a lady and went back after the Marine Corps. Australia is a beautiful country. Thanks!

 

[chiefCW2]

Mr 007, you seem to think the relays are working on this machine. Sense the none of the idiot lights work on this machine including the alt light. do you think if I put a light in this system the alternator would start charging?
Thanks

 

[007]

hello ChiefCWA,
Yes perth is ok but most people in Aus live on the eastern coast.
Not quite sure what you mean in your last post, i assume you meant not much of your instrument lights work any more.
In a normal motor car the alternator light is critical and is used to excite the alternator when you start the engine.
But your machine has two items to get your alternator away being the dash alternator warning light and a small resistor at the alternator wired to the output terminal.
This is assuming yours is the same as the posted wiring diagram, and the non genuine alternator has been wired correctly.
So yes to your question the non genuine alt prob has not got a resistor on it so you need the light to get the alternator started.
Cheers

 

[chiefCW2]

Ya your right none of the lights on the dash work. I have never taken the dash apart it might just need a light bulb to make the alternator work. That would be good. Someone said this is a latch system. I don't understand how to make the system unlatch when you kill the engine and turn the key off.
Thanks for your help.

 

[chiefCW2]

Mr 007,
How is everything down under? I have taken the relay apart and cleaned the contacts. It seemed to help but the relay still sticks sometimes. If I turn the key from off to start and back several times it will start. So sometimes the relay works right and sometimes it don't would you have an idea what to check next? I took the dash apart and none of the lights worked but the glow plugs light and the fuel Gage. The bulbs screw into the printed board. But I couldn't get the dash completely apart so I couldn't check for voltage. Their for I couldn't check why the batt light was not working. Could you help.

 

[007]

Yes it is a latch system and it unlatches when the engine stops.
What relay did you pull apart, the starter safety relay??
What do you mean it sticks some times, means nothing to me without knowing what relay you are talking about and how you are testing it.
You have to be more technical with your approach and use a bulb or multi meter to test things or you will get no where.
The symptom of intermittent starting that you are describing is commonly worn out brushes in your starter motor.
That can be tested by bridging out the terminals at the starter to bypass all other wiring.
And if the starter is engaging intermittently its a starter problem.
The key has to be on for the battery relay to be enabled when testing.
If your wiring and dash is in a mess you can put a bulb or resister directly on the back of the alternator if you just want to get it charging.
Cheers

 

[chiefCW2]

This is a Diesel engine so when I cut fuel to the engine and the engine stops the alt stops then the relay unlatches is that correct?
I took apart the largest of the three relays inside the access door that opens to the radiator. It was the one that clicked when the key was turned on. It has a large cable from the batt and I thank the other goes to the starter. I thought the contacts stuck together because the contacts are made of copper and there was burnt places on them. I used sand paper to clean the black spots on the flat copper pieces that the cables are attached to. Then I cleaned the flat round copper piece that carries current from one cable to the other.
The dash didn't look like anyone had ever been in it. I didn't have my meter with me the day I was there. When I go back to the machine I guess I need to take my multi meter and check voltage at the switch and alternator. The starter brushes could be bad but I don't thank so. I will check them when I go back to the machine. I like the idea of putting a resister on the back of the alt to make it charge. What size would I need and would I get my current straight from the batt?

Thanks

 

[007]

Yes you are correct but left out a bit of detail.
There are three relays there if your machine matches the schematic.
There is the starter safety relay, load damp relay and the battery relay.
You pulled to pieces the battery relay which is energized at first by turning on the key.
When the engine starts the load damp relay senses that the alternator is operating and keeps the battery relay energized until the engine stops.
So assuming you have done a good job of cleaning the contacts in that battery relay and it is working correctly then the only causes of your intermittent starter would be loose wiring, ignition switch, faulty starter safety relay, or faulty starter.
You can use a resister to excite your alternator, you can use a 200ohm 5watt ceramic wired between the alternator output terminal and the warning light terminal.
I would recommend you use a 24V aprox 2watt watt bulb wired in the same place.
You can buy a small inline bulb holder from auto outlet or electronics store.
Some people use mini festoon bulbs and they fit perfectly inside a inline fuse holder.
It has to withstand the heat of the bulb so buy appropriate item.
The bulb would give quick visual guide as to the operation of your relays and alternator.
The bulb should be off with the engine off and ignition off.
On with the ignition on and then go out when the engine starts.
Keep in mind heat and vibration when your wiring at the back of your alt.
Clamp your wires with some small cable tires and some tubing so they don't wear through.
Cheers

 

[Coaldust]

Holy thread resurrection! I needed that ancient Hitachi wiring diagram that -3Doc posted in 2017. Now, I can fix my customer’s antique, dirty, greasy, hoe with confidence. Under the midnight sun, no less. I love this place and all you crusty bastages.