rectifier repair

[cod 121]

Any chance that one can rebuild the rectifier when it goes bad?

 

Now then, I don't know why rectifiers fail but it looks like one could remove the material that seals the guts from the weather and "possibly" replace the internals but I'm all ears if some of you have tried it already.

 

I noticed this weekend that the amp meter wasn't charging and when I checked the battery the voltage coming in was 12.3V which didn't seem like enough to recharge battery.  My first thought was to clean all the battery connections and the ground as well but it didn't help.  I finally decided to check the output from the rectifer so I stuffed positive probe from the voltmeter into the back of the connector that leads to the center wire on the rectifier to see what the voltage was.  I put the negative probe on the negative battery terminal and found 12.3V.  I removed the bolts holding the rectifier in postion, switched to AC and probed the stator leads.  At full rpm (and a couple of sparks later, watch out for the intake manifold ), I found I had around 38+ V, which I believe is about right for a Kohler twin. This led me to believe the rectifier was bad and luckily I've got another 418 for parts, so I switched rectifiers and now I'm getting 14.5 to the battery which solves the low charge problem.

 

As I said, I'm lucky that I have another tractor for parts but "normal" folks may not so once again if this is something anyone could repair, it would be neat to find out how to do it as Jack's Small Engine gets enough of my $$$ as it is.

 

Cod

 

 

 

 

[rmaynard 16,208]

Several years ago, one of our members began a thread called the Regulator/Rectifier autopsy. If I recall, it never was finished, and the results are still pending. But I think the gist of it was that in most cases it was cheaper to just go buy a new or good used one.

 

Here is one source for new. eBay is another good source for one for under $40.00 delivered.

 

http://www.milfordpower.com/R10297-Voltage-Regulator-Replaces-Kohler-41-403-06-p/r10297.htm

Edited November 4, 2014 by rmaynard

[Save Old Iron 1,571]

COD,

 

good troubleshooting and yes, there are some faults with RR units that can be repaired by individuals with the proper skill sets.

 

I did a complete and fully documented an RR autopsy many years back, and many useful discoveries were made from the process. Not surprising,  these discoveries are still posted here as first round fixes - most times by the very same people who thought the original post was "useless". Go figure.

 

The original post was apparently lost when the RedSquare site migrated to a different server. It's a shame really, as the original post had over 50,000 views in just one year! I really never figured it would be one of the all time most viewed posts on this site!

 

My question to you would be are you willing to spend $20 to fix an RR unit that could be snagged of Ebay for $30?

 

If the answer is NO, then just save your pennies to purchase a new regulator.

 

If your answer is based on gaining knowledge of how these regulators are constructed, how they function, and if the possibility exists that yours might be able to resurrected, then we can continue. After the previous post was "lost in the move", I continued off line conversations with several individuals who continued to show interest in the learning aspect of the post. I would be happy to send you a PDF file documenting the deconstruction of the RR, the weak areas of construction and the areas which can be accessed and repaired.

Edited November 5, 2014 by Save Old Iron

[Save Old Iron 1,571]

FYI,

 

the autopsy was performed on an older style "finned" regulator commonly found on the C series tractors. I don't recall if you mentioned which style of regulator you replaced - finned or Onan style.

 

I do have some failed "Onan" style regulators submitted by several folks over the last few years. They will also see the cutting edge of my newly acquired mini mill.

[AJ_Thanatos 516]

I would like to see that pdf Save Old Iron, Is there any way I can get a copy? 

[rmaynard 16,208]

It is available to download in the electrical section of the manuals.

[AJ_Thanatos 516]

Thanks bud! I will go dig it up! and link it here for any other scavengers like myself! 

[AJ_Thanatos 516]

Here is the pdf in question. 

 

[Save Old Iron 1,571]

I'll send out the full pdf to those who request it. The tear down represents a chapter in an E book I'm writing on tractor repair so I want to control the copies I send I before the book gets completed.

[ericj 1,579]

S.O.I. i have several onan RR that 1 terminal has corroded and broken off. is this something that can be repaired by simply soldering a new lead back on ?

 

 

 

 

eric j 

[AJ_Thanatos 516]

S.O.I. i have several onan RR that 1 terminal has corroded and broken off. is this something that can be repaired by simply soldering a new lead back on ?

 

 

 

 

eric j 

Depending on what terminal it is, you can run both wires off the one terminal they are internally connected any way. I would post up pictures first so we can verify.

[ericj 1,579]

ok i will see if i can find them and take some pictures in the next couple of days

 

 

 

 

eric j 

[AJ_Thanatos 516]

ok i will see if i can find them and take some pictures in the next couple of days

 

 

 

 

eric j 

 

Thats also assuming the Onan is using the same RR that the older C tractors used.

[ericj 1,579]

onans use a different RR then the old kohlers

 

 

 

eric j 

[cod 121]

The type of rectifier I have was made by Kohler and it has 3 horizontal spade connectors like this ---.  The two outer ones connect to the stator, while the middle one goes to the ignition switch.  I'd be willing to learn how to fix it just because I'm curious about how stuff works and I'd like to be more self reliant.

 

Cod