Tim's CBX alternator - way high output


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dcarver
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Tim's CBX alternator - way high output

Post by dcarver »

New Tim's CBX alternator is outputting 17-19 vdc on my 81 CBX. It's been back to Tim's twice for refurb.
The repair shop Tim's uses said to check voltage on black wire to ground. (Black wire from disconnected OEM regulator, 3 wires, black, green, red/white).
Image

Voltage should be 4 - 9 volts, mine is 11.9, key on.
Image

Per repair shop, if voltage on black wire is high, or voltage reversed, alternator output very well could be 19 vdc or so.
Looking at schematic, I don't see how voltage on the black wire could be anything substantially less than battery voltage. Maybe a bit less due to minimal losses, but not 4-9 vdc vs 12.7

Image
Additionally, my understanding is field current is initially supplied by battery when engine isn't running. After start, output from the diode trio pack is fed back to the regulator, taking the battery out of circuit.

I would sure appreciate any feedback and advice. Even better if someone could take time and measure their black wire to ground, key on?
Complete write up here. https://candybuttorg.ipage.com/cba/node ... omment-910

I should add that Bill has been GREAT to work with, this is NOT a slam on Bill or Tim's CBX. Please don't read *any* negativity into this post, there is none. This is simply a technical issue that I'm learning about and a reach out for help.

Thank You, Don

daves79x
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Re: Tim's CBX alternator - way high output

Post by daves79x »

The black wire should have battery voltage at all times with the key on. Problems like this only make me more convinced to repair the stock alternator and go with that. Many guys run the conversions without problems, but both systems have their faults. At least you can repair anything wrong with the stock alternator. Sorry, I can't help you further.

Dave

dcarver
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Re: Tim's CBX alternator - way high output

Post by dcarver »

daves79x wrote:
Sat Jun 05, 2021 8:31 am
The black wire should have battery voltage at all times with the key on. Problems like this only make me more convinced to repair the stock alternator and go with that. Many guys run the conversions without problems, but both systems have their faults. At least you can repair anything wrong with the stock alternator. Sorry, I can't help you further.

Dave
Thanks for reply, Dave.

I called the alternator refurb shop and spoke to tech Jesus. They say it tested just fine on the bench with 4-9 vdc of field winding voltage. He also mentioned that he thinks the ZX7 alternator grounds via the case and not through the harness? I have to review my notes..

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Re: Tim's CBX alternator - way high output

Post by CBX-tras »

The Tim's units don't have a dedicated ground like mine did. (green wire). Almost every conversion I've seen doesn't. Kawasaki didn't provide that since it attached directly to the case but, in the CBX it attaches to an adapter plate which attaches to the case. Another layer for the return path (ground) to make a 100% connection that it sometimes doesn't do.
If there's any resistance in any of the circuits, the voltage regulator will see that as a a need to provide more power.
De-pin every terminal in all of the alternator circuits and check for cleanliness and grip to the mating terminal.
Adding a dedicated ground would be highly recommended if you have the skills and materials.
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AshishNJ
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Re: Tim's CBX alternator - way high output

Post by AshishNJ »

I am going add a ground to mine even though mine provides proper output.

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