Ferris model 1000 charging system

oldnslo · Jul 9, 2011

Working on Ferris with the Kawasaki FH641V engine charging system. Battery will not stay charged and I have performed the following diagnostic tests.

Cleaned battery terminals: Note engine spins over fine when the battery is charged so don't think it is a battery issue.

I have checked the stator output and it meets resistance specs and AC voltage output specs. Min 26 VAC & Getting over 30 VAC

I checked the voltage regulator for ohms readings across the three poles and they are all to spec.

Problem I am having is the DC output on pin "B" is negative and it is connected to the positive terminal of the battery.

Vary the engine speed and the regulated voltage goes from 7 - 14.4 VDC.

If I connect the battery connection to regulator I get NO change in voltage at the battery terminals. Manual says it should increase to the regulator output.

Any suggestions on what to look for?

TIA
Roy

Carl_NH · Jul 10, 2011

I suspect you might have a bad battery - they are not $$ $40 - or you could pull one from another machine you have and see if it charges.

Batteries can do strange things - like this season my Cub PTO stopped working in the middle of cutting - would start then cut out. Voltage and output to the battery were fine but when I took it out of the machine and tried to charge it - it would not hold.

You can take it to an autoparts store too and they will load test it free. Mine did not even register on their tester it was so dead.

Carl

nomad289 · Jul 10, 2011

"Problem I am having is the DC output on pin "B" is negative and it is connected to the positive terminal of the battery"

How can this be? Is this a new machine or was something altered?
I would double check to see which pin is providing a positive charge; then re-wire (if this is a first time problem with used equipment) to ensure positive charge goes to positive, and negative goes to ground. Just use a probe light to check the polarity and ground to negative on the frame.

IF indeed the unit polarity is reversed then feeding 12v positive into the negative terminal of a battery might result in no voltage change---battery would negate (absorb) the improper polarity charge.

I like the previous suggestion of putting in a good battery to check the system--much more likely than reversed polarity wiring.

oldnslo · Jul 10, 2011

Thanks guys, I was thinking about swapping batteries but the "reversed" polarity bothered me. I have the wiring diagram for the Ferris and it does not appear to be altered. I also have the wiring and diagnostics for the Kawasaki motor so.... Different known good battery it is.

Roy

oldnslo · Jul 12, 2011

Situation update:

Battery was the culprit. Once again check the obvious first.

Voltage regulator: Requires a load on "B" terminal to become positive.

Roy

Carl_NH · Jul 12, 2011

Glad it was an easy fix - you did a good job isolating the issues and the negative polarity aspect needing a load on B terminal is good info.

My Ferris 2000 (new last year) as a leftover 09 unit arrived with a bad battery - would only register 11.6 volts when running - the dealer checked out the charging system and found it was a bad battery - all is good on that machine now - 14.6 volts running.

Similar to my Cub Cadet too, PTO would not engage but tractor would start and run - battery just didnt have enough good cells left to operate the PTO.

oldnslo · Jul 13, 2011

thanks Carl,
I talked to a friend of mine that works on electronics for air planes and he couldn't give me a definite answer why the regulator voltage changes with load so it is still a mystery.

Reason I didn't suspect the battery is that is showed a charge of 13.2 VDC that dropped to 12.8 VDC when the engine was cranking. I didn't think a 0.4 VDC drop was unusual while the starter was engaged.

Roy