JD 310D Alternator/Accessory Relay

[vagabonddreamer]

hello all, this has partially been addressed in the past but i am looking for some confirmation. I have a 96 310D. It has intermittently had problems in the past where after starting the ALT light comes on and i have no 4X4 or lights or heater fan or windshield wipers. Usually after a while everything goes back to normal. I just off loaded a truckfull of round bales in the snow and thankfully everything worked until i was just about finished and then all those things i mentioned ealier stopped working and the ALT light came on. With the backhoe running i can jumper 12v to the D+ terminal and the ALT starts to charge and does so until it reaches the required level and then it stops and wont come on again until i jumper the terminal. |During this time even though the ALT is charging i still have NO lights 4X4 etc. I did manage to locate the accessory relay/solenoid. Before i pull it out is there ANYTHING i should check with respect to fuses or relays?? thx so much...vs

 

[franklin2]

Do you have a wiring diagram for it? I don't have one, but I have worked on a lot of charging systems on different tractors and vehicles.

Usually the "ALT" light in the dash has a plastic socket with two wires going to the bulb. The bulb is not grounded. One of the wires going to one side of the bulb comes from a key-on 12v power source. The wire on the other side of the bulb leaves the dash area and goes either to a separate regulator or a integral regulator made into the back of the alternator. There is a special terminal usually for this wire either on the separate regulator or the alternator.

So when the key is turned on, you have 12v on one side of the bulb from the key-on source, and nothing on the bulb side going to the alternator. So the bulb lights up. After the engine is running and turning the alternator, the charging system puts 12v on the alternator side of the bulb wire, so the light goes out. That is because you have 12v from the key on one side of the bulb, and 12v on the other side from the charging system, so there is zero volts across the bulb and it goes out.

If the engine stalls and the key is left on, the alternator light lights up because you lose the 12v from the charging system, but still have the key on.

In your case,it sounds like you are losing key on power, since some other things are not working also. So you might have a residual voltage on the alternator keeping it charging for awhile, which would put 12v on the charging side of the "alt" light, but if you are losing 12v on the key-on side, then the light is going to light up.

 

[mg2361]

Most likely your accessory relay is defective. When the issue is happening, confirm you have good voltage to one of the large posts. Then make sure you have voltage and a good ground to the relay's control circuit. If it is and you have no voltage at the other large post, then you need the relay.

 

[vagabonddreamer]

Thank you franklin2 and mg2361 for taking the time to reply. it is much appreciated. So, mg2361 in effect when the machine is running there should be voltage at all 3 posts on the relay?? thx...vs

 

[vagabonddreamer]

Hello, further to my previous message. i went out this morning and discovered the following:

• key off engine off voltage to one of the big poles on the accessory relay nothing to either of the other two
• key on engine off voltage to same big pole plus voltage to control pole (smaller pole of the three) no voltage to other big pole
• key on engine running voltage to same big pole plus voltage to control pole, no voltage to other big pole, ALT light on

I guess the relay is done?? thx....vs

 

[joe--h]

Sounds like.

https://www.ebay.com/itm/Relay-AR73...0E-310G-315C-410-410B-410C-410D-/143628870996

$20 on ebay.

If your's looks like the ebay picture you can drill out those 4 rivets and clean the contacts to fix it. That's IF it clicks when you turn the key on. No click it's probably the coil dead and no fixee. Or you can take it apart just to see what's in there.

Joe H

 

[JL Sargent]

It's important to use a 100% duty cycle relay (good quality). I replaced mine about a year ago.

 

[Delmer]

Yes, obviously it has to be bolted tight to ground it so you could check the voltage to the metal base of the relay.

 

[mg2361]

First, What Delmer said^^^^. If you have voltage at the metal base then you have a bad ground. If no voltage, then.....

I guess the relay is done??

Yes

As JL said, it is 100% duty, so buy a good one.

 

[vagabonddreamer]

I have the relay on order from Lordco. I will let everyone know the outcome. I really appreciate the knowledge and willingness to help others, that this site represents. As i have said before, this is nothing to do with not wanting to hire people to fix things, but when you live remote and the drive in for a mechanic takes longer than actually doing the work then it makes sense to try and take care of things internally. This site represents a massive amount of time tested empirical wisdom and the people that are willing to help and share and i sincerely appreciate all who contribute....thx...vs

 

[vagabonddreamer]

Replacing the "accessory relay" was successful and all works the way it should!! I have been guilty of not diagnosing the problem fully in the past and spending money on things that did not need to be replaced. In this case i thought at the beginning that the problem was the alternator but i was determined not to spend money on one until i knew it was indeed the issue. I thank all the people who helped out. This is an amazing site....thx...vs

 

[billybob231517]

Hey everyone I am having the same problem. But I am having trouble finding the accessory relay on my 1996 john deere 310d. By chance does anyone know where it might be located. Also a part number of a good replacement.

 

[Diesel Dave]

Hey everyone I am having the same problem. But I am having trouble finding the accessory relay on my 1996 john deere 310d. By chance does anyone know where it might be located. Also a part number of a good replacement.

Accessory relay part # AR73144 is mounted in the compartment below the side instrument panel.

 

[billybob231517]

Thanks! That did the trick.

 

[vagabonddreamer]

Hey billybob. Diesel Dave is a deity around this forum. He is such a wealth of knowledge and never is never shy about digging in and helping forum members. I was just about to tell you to PM him...vs