Can I test the amps from my alternator like this?

[Treemonkey1000]

Wires and regulators getting hot doesn't seem to be a normal operating mode unless there is a problem. Current clamp is the safest way to measure. Like others have said a Digital meter typically doesn't measure much more than 10 amps. If your wire is getting hot you are going beyond 10 amps unless those are like 18 or 24 gauge wire. I would really start around your wire harness and look for shorts to the chasis. A bad light switch your glow plug timer is holding on.. Something like that.

 

[rsmith02184]

I had a voltage regulator (VR) burn up on me. I replaced it and the 2nd one seemed to fry too. I found a loose connection at the battery and thought that maybe it had been arcing. I replaced the VR again and it started to act weird too. I then found the battery had a dead cell. I replaced it AND got another VR too.

like i said, the wires coming FROM alternator to the VR are getting real hot.

Also, the RED wire going FROM the VR to the battery is also getting hot.

Taking readings in all places (according to the technical manual) all voltage readings look fine.

I just need to find out why it is getting so hot.

How would I test for a bad ground? I put my continuity meter on the ground wire that goes to the VR and it makes a noise so....I am assuming that ground is good.

any ideas about why it is getting so hot?

 

[rsmith02184]

one other thing:

I am getting 14.3 volts (dc) going out of the regulator.

I am reading 13.4 volts at the battery.

this looks good but it is getting hot and I worry about it failing.

 

[jinman]

Smitty, I'm going to be in and out of this forum, so I may not have a prompt answer, but I'm thinking about the wire that is providing 13.4 volts to the battery. I think normally, the charge current for the battery is tied into the regulator line at the starter. Normally a big positive battery lead will go to the starter terminal at the starter solenoid. From that point, many/most tractors have a master current limiter (fuse) that is set at a value for the maximum current draw from the battery for accessories such as lights and glowplugs. The charge current/wire from the alternator/regulator will go to the junction point on the starter at the same point as the battery cable. In other words, it ties directly to the battery at that point and either the battery or the alternator will supply current through the main current limiter (fuse). By lifting the positive terminal off the battery, you will eliminate it from the circuit and only have the tractor's loads of lights and glowplugs on the alternator/regulator wires. You have to do this while the tractor is running because you can't start the tractor after removing the positive terminal. Once you lift that battery lead, you can monitor that alternator wire and the regulator wire to see if they get hot. If they don't get hot with the battery removed, then you pretty much have to consider that you got a battery that is no good. It does sometimes happen. I just think that what you have to prove first is whether the excess load is due to the battery or the rest of the tractor. This will help you identify that.

 

[rsmith02184]

thanks for the advice. I will do what you said and monitor the wires at the VR. I don't think it is my battery but you never know.

I also don't know where the red wire that leaves the VR goes? I thought it went back to the starter switch and then to the starter but now I am not so sure.

 

[Treemonkey1000]

Jinman from what I understand taking the positive terminal off the battery and floating the alternator isn't a good practice. Or did I misread where you just disconnect the battery and leave the wire with the rest of the wire harness connected. i.e. alternator and lights and all of the other stuff?

 

[jinman]

Jinman from what I understand taking the positive terminal off the battery and floating the alternator isn't a good practice. Or did I misread where you just disconnect the battery and leave the wire with the rest of the wire harness connected. i.e. alternator and lights and all of the other stuff?

Yep! Just disconnect battery and let alternator take care of the load. If there is not enough load there to heat up the wire, then the excess load is probably coming from charging the battery. If I were Smitty, I'd turn on the lights to make sure I had several amps of load on the alternator and then check that the voltage is not dropping. I'd also put the voltmeter on AC to see if perhaps there was some excessive ripple getting through the rectifier.

If we had an electrical schematic of Smitty's tractor or one like it, it sure would make this more like troubleshooting and lot less like an Easter egg hunt, but you gotta work with what you got.

 

[rsmith02184]

i have the technical manual with the wiring schematic but unfortunately I am not that good at reading the schematics.

question: what do you mean by "test it to see if the voltage is dropping"? do you mean I should put my meter on the red wire that leaves the VR and see if it starts to drop?

 

[Treemonkey1000]

Yep! Just disconnect battery and let alternator take care of the load. If there is not enough load there to heat up the wire, then the excess load is probably coming from charging the battery. If I were Smitty, I'd turn on the lights to make sure I had several amps of load on the alternator and then check that the voltage is not dropping. I'd also put the voltmeter on AC to see if perhaps there was some excessive ripple getting through the rectifier.

If we had an electrical schematic of Smitty's tractor or one like it, it sure would make this more like troubleshooting and lot less like an Easter egg hunt, but you gotta work with what you got.

Well you are a good Easter bunny then Mr. Jinman

 

[jinman]

i have the technical manual with the wiring schematic but unfortunately I am not that good at reading the schematics.

question: what do you mean by "test it to see if the voltage is dropping"? do you mean I should put my meter on the red wire that leaves the VR and see if it starts to drop?

Sorry, I had to run to town and get some flowers for my wife's birthday which is tomorrow. Nothing is more important than that.:thumbsup:

What I meant is that you said earlier the voltage read at the VR is 14.3 and 13.4 at the battery. That indicates a heavy current load that is dropping almost a full volt. When you have a lot of current, the wires and connections actually cause voltage drop. That's why battery cables are so big and have such large connectors. It's so that when you operate your starter, the cables can handle the current without heating up or causing voltage drop.

Smitty, I don't know if I can help, but I will surely try. If you can scan that schematic and send me a copy, I'll take a look at it and try to come up with a logical troubleshooting method that will find your problem. I'll give you my personal email in the PM that you should receive shortly.

I have some ideas, but I just don't want to Easter Egg your problem and get the Easter Bunny mad at me.:laughing: Treemonkey understands that.