Can relays be tested?....John Deere 2320 electrical issues!!!

[kyles974]

John Deere 2320 .....300hrs
But had a battery go bad awhile back. After that ....the gremlins came out!!!
The tractor doesn't keep battery charged and the glow plug light stays on.

Now I have money...going to try and fix.

After many many hrs reading and searching the forums.........

Pretty sure it's a bad safty relay and maybe glow plug relay too. (I've got to figure out which ones they are)(already have dash/cover off)
But I think the safety relay is around $100.....and would like to see if I can make sure before paying out the money.

So...is there a way to test relays to see if they are bad?

 

[TomSeller]

John Deere 2320 .....300hrs
But had a battery go bad awhile back. After that ....the gremlins came out!!!
The tractor doesn't keep battery charged and the glow plug light stays on.

Now I have money...going to try and fix.

After many many hrs reading and searching the forums.........

Pretty sure it's a bad safty relay and maybe glow plug relay too. (I've got to figure out which ones they are)(already have dash/cover off)
But I think the safety relay is around $100.....and would like to see if I can make sure before paying out the money.

So...is there a way to test relays to see if they are bad?

Are the relays isolated or part of an integrated board? If you can separate the leads of the coil and measure the contacts, you can jumper the coil with 12V and measure the resistance through the contacts.

 

[tomd999]

Hiya,

Before you dive into relays and extensive troubleshooting, I would verify the grounds are connected, clean and tight. When I worked as a mechanic I seemed to have all the electrical problems handed to me, the majority of them were fixed by making sure the chassis, engine, harness and cab/body all had good clean and functioning grounds. One that a lot of people forget about is the braided strap from the engine to chassis, that will cause a charging system to flip out and give you all sorts of weird issues.

My 2 cents,

Tom

 

[kyles974]

Are the relays isolated or part of an integrated board? If you can separate the leads of the coil and measure the contacts, you can jumper the coil with 12V and measure the resistance through the contacts.

Isolated

Hiya,

Before you dive into relays and extensive troubleshooting, I would verify the grounds are connected, clean and tight. When I worked as a mechanic I seemed to have all the electrical problems handed to me, the majority of them were fixed by making sure the chassis, engine, harness and cab/body all had good clean and functioning grounds. One that a lot of people forget about is the braided strap from the engine to chassis, that will cause a charging system to flip out and give you all sorts of weird issues.

My 2 cents,

Tom

Yes....I will be doing this also. (Had to do other things....so had tractor already apart)
But...like I said....it all begin to happend after the dead battery.

 

[bumpyrider]

If it's a relay problem, it sounds like the contacts are welded together. If you test it the way tomseller suggests, the relay contacts should be closed/low resistance with power applied to the coil, and open/no resistance with the power removed. If the resistance does not change, or only changes a little, that's probably part of your problem. The relay should be off the board so you don't get misleading readings from the rest of the circuit.

 

[TomSeller]

If it's a relay problem, it sounds like the contacts are welded together. If you test it the way tomseller suggests, the relay contacts should be closed/low resistance with power applied to the coil, and open/no resistance with the power removed. If the resistance does not change, or only changes a little, that's probably part of your problem. The relay should be off the board so you don't get misleading readings from the rest of the circuit.

Yes, and if they are welded, you will need to figure out why they welded. A new relay would likely just weld again unless you track down what is drawing the excessive current causing the relays to weld. There was a model of Kubota that had a factory undersized relay, but that is rare. Generally something is drawing too much current.

 

[kyles974]

Are the relays isolated or part of an integrated board? If you can separate the leads of the coil and measure the contacts, you can jumper the coil with 12V and measure the resistance through the contacts.

Yes, and if they are welded, you will need to figure out why they welded. A new relay would likely just weld again unless you track down what is drawing the excessive current causing the relays to weld. There was a model of Kubota that had a factory undersized relay, but that is rare. Generally something is drawing too much current.

That would suck....because these relays are not cheap.
I'm not sure exactly how to test like tom mentioned. I've got very good comen sence....with decent electronics knowledge. ...but when it come to reading a volt meter.....well....kinda of a beginner there.

Hopefully in next couple days I can start to get hands back on......and hope to try and figure this out.

 

[tomd999]

Hiya,

Any idea why the battery went bad? Could it have been acting up and the battery was a symptom and not the cause of the issues?

John Deere 2320 .....300hrs
But had a battery go bad awhile back. After that ....the gremlins came out!!!
The tractor doesn't keep battery charged and the glow plug light stays on.

If you don't have one already, you should get your hands on the service manual for your tractor. It will have a troubleshooting section for each system and a detailed wiring diagram. These will be a great deal of assistance working on this and any other issues that come up.

Tom

 

[horsepuller]

Check the wire size going to the load section of the relays, that will tell you the approximate current rating in amps. (wire gage should be marked on the wires, 12 gage = 20 amp, 10 = 30 amp, ect.) Go to an auto parts store and buy an auto-resetting relay, they are usually less than $5. Jumper the relays in place of the original ones, one at a time. If the auto-resetting relay clicks on and off, you have an overload that must be tracked down by disconnecting individual loads. If the circuit works OK, then you know the original relay is bad, and can replace it. Good luck.

 

[kyles974]

Check the wire size going to the load section of the relays, that will tell you the approximate current rating in amps. (wire gage should be marked on the wires, 12 gage = 20 amp, 10 = 30 amp, ect.) Go to an auto parts store and buy an auto-resetting relay, they are usually less than $5. Jumper the relays in place of the original ones, one at a time. If the auto-resetting relay clicks on and off, you have an overload that must be tracked down by disconnecting individual loads. If the circuit works OK, then you know the original relay is bad, and can replace it. Good luck.

Thank you so much sir. Even if the resetting relays are $20.....it's still worth it.
I am heading to town and will pick one up.
(I just went out to look at wires and did notice one of the electrical clips that go to a relay was just slightly pulled out....not sure if enough to make a bad connection? Hopefully it was!!!.....but I doubt it....lol)

I appreciate the help so far from everyone!!! Greatly!!!

 

[bumpyrider]

Don't forget that service manual, too! They're well worth the money if you plan on keeping the tractor...
Since you said the glow plug light was always on, one quick test you could do is (once you've located the glow plug relay) have someone turn the ignition on (not start, just on) while you listen and maybe touch the relay, if it's safe (I don't where anything is on your rig). The relay should click when the ignition is turned on, and after a short time the relay should click again after the glow plug has heated up. If you don't hear or feel the relay change at all, you could be on the right track.
Without the electrical schematic, I'm totally guessing here, but the relay is probably operated by a timer, and the glow plug comes off of one set of contacts, the indicator light off of another set. If you can measure the voltage on the coil (sometimes marked A1/A2 on the terminals) you should see 12volts there only during the normal glow plug warm-up time. If the 12volts on the coil does not go away, your problem is before the relay.
Like Tom said, the best thing is to get the manual and start following the troubleshooting charts. The problem might not be here at all and I'm just "leading you down the garden path..."

 

[kyles974]

Don't forget that service manual, too! They're well worth the money if you plan on keeping the tractor...
Since you said the glow plug light was always on, one quick test you could do is (once you've located the glow plug relay) have someone turn the ignition on (not start, just on) while you listen and maybe touch the relay, if it's safe (I don't where anything is on your rig). The relay should click when the ignition is turned on, and after a short time the relay should click again after the glow plug has heated up. If you don't hear or feel the relay change at all, you could be on the right track.
Without the electrical schematic, I'm totally guessing here, but the relay is probably operated by a timer, and the glow plug comes off of one set of contacts, the indicator light off of another set. If you can measure the voltage on the coil (sometimes marked A1/A2 on the terminals) you should see 12volts there only during the normal glow plug warm-up time. If the 12volts on the coil does not go away, your problem is before the relay.
Like Tom said, the best thing is to get the manual and start following the troubleshooting charts. The problem might not be here at all and I'm just "leading you down the garden path..."

I will GLADLY take any advice....even if it leads me in wrong direction. ...lol
As a said....my expertise in this leval of electronics are slim.

Also...I do have the service manual. Found one used one on the bay a while back. But...not sure if any has tried to look up something in these......wow! It's almost another laungue. Kinda frustrating. But I do plan on opening the book back up.
Wanted to try my luck out here first...since most seem to be on the "same page" in the words of speaking.
In fact....today...was talking with my dad o phone....told him about the service book...he lmao....almost...roflmao at me because they way I said it.

Last time I looked thew the book I was like wtf! ...lol

Ok...I just opened the service book....what would you think you could find relays under? Relays right? Nope! .....lol
Ok...maybe under electrical system right? Nope again.....
Anyone know what an engineer would call a relay?

 

[bumpyrider]

That little square greasy thingy...

Actually, I did a quick search and found they might refer to it as a 'module'.

Also found a reference to a controller/timer on a different JD, http://www.tractorbynet.com/forums/parts-repairs/281477-john-deere-4100-glow-plug.html

Just thought you might want something to do today!

 

[k0ua]

Relays are just called Relays. Here is how they work.
Let us talk about the simplest relay, one that has a single set of contacts that only go in on direction to make an electrical connection when energized. We call this a SPST relay. It is Single Pole, Single Throw.

What that means is there is just a single set of contacts (the single pole) and it just moves in one direction when energized and does not make any connection when it is relaxed. So what causes the single pole to move? All relays have at least one coil. A coil is just what it sounds like a coil of very small wire. If we apply 12 volts on one end of this coil and ground on the other, electrical current will flow in this coil of wire.

This coil of wire has resistance that you can measure on an ohm meter, it will be fairly low, but not 0 ohms. So what happens when we pass this current thru this coil of wire? A magnetic field is generated in this coil of wire when current is passed thru it.

This magnetic filed attracts a piece of steel called the "pole piece" which has the movable contact of this set of contacts we talked about, towards the non moveable contact until they touch. These contacts have leads attached to them and brought out side of the relay enclosure. As long as the coil is energized by the electrical current flow these contacts will will remain "closed" and making contact with each other. The resistance between the contacts when they are touching together should be near 0 ohms.

So what is the overall point of a relay? Why do we need them? Well they allow small amounts of current to be used in controlling large amounts of current. For instance we could have weak small relay coil current be able to switch on a huge amount of current that would be used to control something like a starter solenoid, or the huge amount of current that glow plugs require.

You could not for instance run the glow plug circuit thru the key switch ( you sure would need an awfully large key switch) but with a relay, you can easily accomplish this with just a tiny current from the key switch to control the glow plug relay whose SPST contacts now control a huge current (in the order of 60 to 70 amps).

So in summation. a simple relay is an electro-mechanical device that a small current passed thru its coil will cause mechanical movement of a set of large current carrying capacity contacts inside the relay to operate much like a large switch.

When the relay is relaxed (not energized) the contacts are "open" in other words infinite ohms, and when the relay is energized the contacts are "shorted" or 0 ohms.

There is more of course, like all subjects electrical, but I hope that this gives you some idea of what relays are and how they work.

 

[kyles974]

That little square greasy thingy...

Actually, I did a quick search and found they might refer to it as a 'module'.

Also found a reference to a controller/timer on a different JD, http://www.tractorbynet.com/forums/parts-repairs/281477-john-deere-4100-glow-plug.html

Just thought you might want something to do today!

Relays are just called Relays. Here is how they work.
Let us talk about the simplest relay, one that has a single set of contacts that only go in on direction to make an electrical connection when energized. We call this a SPST relay. It is Single Pole, Single Throw.

What that means is there is just a single set of contacts (the single pole) and it just moves in one direction when energized and does not make any connection when it is relaxed. So what causes the single pole to move? All relays have at least one coil. A coil is just what it sounds like a coil of very small wire. If we apply 12 volts on one end of this coil and ground on the other, electrical current will flow in this coil of wire.

This coil of wire has resistance that you can measure on an ohm meter, it will be fairly low, but not 0 ohms. So what happens when we pass this current thru this coil of wire? A magnetic field is generated in this coil of wire when current is passed thru it.

This magnetic filed attracts a piece of steel called the "pole piece" which has the movable contact of this set of contacts we talked about, towards the non moveable contact until they touch. These contacts have leads attached to them and brought out side of the relay enclosure. As long as the coil is energized by the electrical current flow these contacts will will remain "closed" and making contact with each other. The resistance between the contacts when they are touching together should be near 0 ohms.

So what is the overall point of a relay? Why do we need them? Well they allow small amounts of current to be used in controlling large amounts of current. For instance we could have weak small relay coil current be able to switch on a huge amount of current that would be used to control something like a starter solenoid, or the huge amount of current that glow plugs require.

You could not for instance run the glow plug circuit thru the key switch ( you sure would need an awfully large key switch) but with a relay, you can easily accomplish this with just a tiny current from the key switch to control the glow plug relay whose SPST contacts now control a huge current (in the order of 60 to 70 amps).

So in summation. a simple relay is an electro-mechanical device that a small current passed thru its coil will cause mechanical movement of a set of large current carrying capacity contacts inside the relay to operate much like a large switch.

When the relay is relaxed (not energized) the contacts are "open" in other words infinite ohms, and when the relay is energized the contacts are "shorted" or 0 ohms.

There is more of course, like all subjects electrical, but I hope that this gives you some idea of what relays are and how they work.

The first quote above.....thank you!! That is great info.
The second.... great info too....learned something. Thank you for taking the time to write all that out for me.


My house was flooded back in April. (Lower half....we been living in upper part that was an addition and sit on blocks...which is kitchen ...living....bath....and one bedroom. .....me...wife....and two girls..5&8.....so been very busy trying to get the damage finally fixed.....been a stressful summer! My closet has been a ccardboard box behind couch in livimg room.....which is filled with boxes of things that made it threw the flood)

Anyhow. ....most of my time has been focusing there. Today I'm taking day off. Goimg to go tinker on the tractor and see what I find. I will post later.

Bit again.....a big thank you to all that has been helpimg along.