Can I test the amps from my alternator like this?

[Transit]

I've made a simple diagram of an alternator charging system that may help to see what is going on. The last time I tied to upload the file it would not go. The diagram was created in Visio and printed as a PDF file using PDF995. The file should upload; I do it all the time at work for those who do not have access to Visio to open the file.
Here goes again.

The PDF file is uploaded, but when you try to open it, a window opens to my desk top. I'll have to remove the PDF file till this is cleared up.

Another try with an older pdf file.

Nope! same results.

OK, it works!! Open the file as a Word Doc.

You can open the file now in post # 74.:thumbsup:

 

[John47]

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.

NEVER remove an alternator from it's load, ie battery. The regulator requires the battery as a reference voltage.
Removing an alternator from the battery while running will cause the regulator to increase field current and a sudden voltage rise will be the outcome. That voltage will be too high for the solid state components to handle, diodes and transistors will fry!!
You also risk blowing every bulb and electronic device on the machine!!
Just my two cents worth ....

 

[rsmith02184]

no I don't have a clamp on meter. I know, you are all saying "just get one". However, they are about $100. More than I want to spend right now.

I am new to my part of Indiana, so i don't know a lot of people yet, but I will contact one guy and see if he has one.

I scanned the wiring schematic but I don't think it came out right. I will scan it again later on today.

thanks

 

[rsmith02184]

I can see now that the schematic didn't come out right. I will fix it soon.

 

[jinman]

NEVER remove an alternator from it's load, ie battery. The regulator requires the battery as a reference voltage.
Removing an alternator from the battery while running will cause the regulator to increase field current and a sudden voltage rise will be the outcome.

I hate to get into a side discussion/disagreement, but this needs to be addressed. On my tractor and most others I have seen, when you turn off the key switch, you disconnect the "R" lead from the battery to the alternator by opening switch contacts. The alternator does not suddenly put out a surge in voltage nor current. Let's say you have the lights on. When you shut off the key, do the lights suddenly go "poof" like a flashbulb before the engine stops spinning? I don't think so. If you have a battery with dirty terminals and making intermittent contact, does the alternator go wild and burn up anything attached? I will not argue that it is a bad idea to run a vehicle with an alternator and the battery disconnected for a long period of time, but as a troubleshooting aid, disconnecting the battery for a few seconds will hurt nothing, especially if you have the lights or something else to provide a minimum load on the alternator's output. If you want, I can show you the circuit diagram, but I'd rather not do this in this thread because it distracts from finding Smitty's problem.

 

[Soundguy]

Well, I first thought that was the case, but I looked at my meter and it only does AC current. When I did a google search, I only found $400 Flukes with both AC and DC current. I'm glad you debunked my theory. I'll have to change my statement to "a lot of cheap meters only read AC." Thanks for the correction and link Soundguy.

your not wrong.. just the definition of cheap changed

I can find 10-30$ clamp ons.. I DEFFINATELY consider those as cheap meters.. and as you say.. they do ac amps only.

Once you hit the 50-60$ range.. you can find clamp ons that do dc.. that sears one is popular, as well are the chines knock offs of it. I'm sure there are others.. that's just 2 sets I'm familiar with. I'm guessing the average tractor owner may not want to spend 60$ on a meter when a 10$ meter will do 95% of their stuff.

soundguy

 

[Soundguy]

NEVER remove an alternator from it's load, ie battery. The regulator requires the battery as a reference voltage.
Removing an alternator from the battery while running will cause the regulator to increase field current and a sudden voltage rise will be the outcome. That voltage will be too high for the solid state components to handle, diodes and transistors will fry!!
You also risk blowing every bulb and electronic device on the machine!!
Just my two cents worth ....

depends.. and not just the adult diaper..

if it is a permanent field type charger....

soundguy

 

[jinman]

I can see now that the schematic didn't come out right. I will fix it soon.

Hang in there and keep trying Smitty. You got a lot of folks dyin' to see your diagram and try to help you.:thumbsup:

 

[Transit]

k7ln, than we need the correct prints.

 

[Transit]

If all else fails, replace the alternator with a 50 amp, one wire unit with a built-in regulator. Not stock, kind of crude but it will get the job done.