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Asked the question in another thread, but decided it needed wider exposure. Anyone here tried one? Did it help with stator longevity in your case?

Theory is, a series regulator will help a stator run cooler since the windings won't be switched on 100% of the time.

Just looking for confirmation that it was a benefit to someone (other than the seller :)) before I replace my FH020AA with a SH775.

Thanks in advance...
 

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1986 VN750
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I mean, unless your FH020AA is not functional, then it's not worth swapping.

The SH775 is a 35 Amp MOSFET. Good unit.
 

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I have installed a Shindenger SH775 series R/R and am still having problems. I bought a 2000 Vulcan 750, US model in Sept 2015. The bike had a bad stator, suspected bad OEM shunt R/R, bad fan relay in junction box, and a mess of spliced wires in the headlight basket. I couldn't work on it full time, but I have a couple of months effort's in it. I replaced the stator, got another junction box from ebay (full tested IAW Haynes Kawasaki Vulcan 750 manual) and the SH775. Initially I made an adaptor for the regulator to plug into the original wiring harness. The harness needed work so I replace a lot of terminals, connectors and fixed bad splices. The 3 yellow stator wires got real hot so I replaced the 3 bullet connectors with a Walmart 4-pin trailer connector soldered to the yellow wires. This let the yellow stator wire run very cool and easily disconnected for stator testing.

The best I could get from the SH775 was 13.6V at the battery terminals. But the big problem is a 20 mA drain at the battery. I would take a ride, the bike would barely charge and due to the 20 mA drain, wouldn't restart after shutting it down. I wanted to use the original harness because I expected it to work, apparently it has problems. To help isolate the problems and minimize variables, I connected the SH775 as recommend. The 3 yellow stator wires into the SH775 and Red wire from SH775 to positive battery terminal, Black wire to negative battery terminal. Thought I had it fixed. The SH775 with just a little throttle put out a consistent 14.35 V. After a ride, the bike would start right up. But the next day it wouldn't start. The 20 mA drain was still there. I disconnected the SH775, and only applied battery voltage to it, and there was voltage on the 3 stator connectors. Apparently this voltage was causing the headlight relay in the junction box not to release. By disconnection the Reserved Lighting Unit OR the Starter Relay (on side of battery box) the 20 mA drain went away. Further confirming the voltage on the stator wires with bike off, key out is causing the drain.

I did a google search for "SH775 current drain" and found others have same problem. I haven't had a chance to find a work around yet. Some possibilities are relocate the blue headlight wire from pin 8 to pin 7 on the 8-pin junction box connector. Then remove the yellow wire on pin 9 of the 10-pin connector on the junction box. This yellow wire is split off of one of the 3 stator wires to activate the headlight relay after the starter button is depressed. Any other suggests would be appreaciated.

BOTTOM LINE: It appears the SH775 series R/R produces a current drain on a Vulcan 750, but connected correctly it puts out great voltage and runs very cool compared to the OEM shunt R/R.
 

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Hi Vulcanizer, welcome to the forum.

That SH775 leak is pretty weird. Thanks for sharing those details.

It seems pretty obvious that the R/R is allowing battery current to flow backwards through pin 5 (white wire) into the R/R, then out through the yellow stator wire to the headlight relay, which has it's path to ground through the starter relay.

As you mention, doing the blue-wire mod (allowing the disconnection of the yellow stator wire from the junction box) is the easy fix.

An alternate fix, possibly never done before, would be to add an in-line diode at the regulator connector to allow current to only flow out of the regulator. This would have to be placed between the R/R and the splice in the harness where the JB, battery, and R/R connect since current needs to flow both directions on the junction box leg of the splice (out to ignition when starting, in from R/R when charging). On the R/R side of the R/R connector seems like the natural place to add it.
 

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20ma drain is not enough to kill a fully charged battery overnight.

thats 0.020 Amps.. while I dont know the exact numbers, ballpark for amp/hr drain (sustained drain for 1 hr), is at least 10 a/hr. sooooo, it should be able to hold 20 ma drain for like 500 hrs.
 

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Thorn - Thank you, Your suggestion of a diode is an excellent one. I was just trying to answer the initial question of "has anyone tried an SH775" with my own experience. When I disconnect the SH775 and only apply battery voltage, I get voltage on the 3 stator connections. I had access to a second SH775 and it did the same thing, while the OEM shunt R/R does not have voltage on any of the 3 stator connections. Seams like a design flaw that your diode may fix. Another interesting symptom is when I turn the key to the on position, the headlight is off until I hit the start button, then the headlight comes on. This is the way it's supposed to work (I think). Then when I turn the key off and then back on, the headlight is on. When I disconnect and reconnect the battery, the headlight functions like it's supposed to. Seems like there isn't enough current to trigger the headlight relay, but enough to not let the headlight relay disengage. Someone else suggested a resistor to reduce the current or replacing the relay with a different one. I have a spare junction box I got on ebay and have fully tested it. It also has the same symptoms, so I'm satisfied the headlight relay in the junction box is not defective. I'll try the diode when I get a chance otherwise I may go to a MOSFET R/R. Acceptable or not, I don't think there should be any current drain.

Michigan TB - Your calculations seem right. I'm in an area where I don't really know anyone. With some many electrical problems and being stranded so many times, I'm trying to take things one step at a time. I have the SH775 hooked up directly to the stator and the battery. With digital voltmeter installed, I am getting consistent 14.35 volts at the battery. I have been taking short rides (10 miles or less) to ensure the charging system was working before venturing out on a long ride to fully charge the battery. I thought of putting the battery on a trickle charger overnight but if the charging systems wasn't working correctly I would just get stranded further from home. When I initially wired the SH775 through the wiring harness the best I got was 13.6 V at the battery. That stranded me several times. I believe you need at least 13.8 V to charge the battery. Now with the charging system working, I'll take a long ride and see if the bike starts next day, then I'll work on the current drain. To drive your point home, when I initially put the bike together with SH775 and new AGM Battery, I rode everyday for a month with no problems. Didn't know I had a current drain. I let the bike sit for about 3 months then found a drained battery.

I love this forum and thank you guys for your thoughts.
 

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Just a thought, your battery might be shot now after a deep discharge. I've had major starting troubles with a dying battery (which is under a year old but failed the autozone battery check miserably) ... a minor leak might be "the straw that broke the camel's back" when trying to start on a borderline battery. Worth having it checked.

Again, thanks for the details. Every bit helps answer questions down the line!
 

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one thing to remember on the battery. even if you buy it today, it may well be over a year or even 2 old... they sit a while on the shelves. you can always check date code on the battery before you puchase it, it should be on a sticker on the side of the battery
 

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one thing to remember on the battery. even if you buy it today, it may well be over a year or even 2 old... they sit a while on the shelves. you can always check date code on the battery before you puchase it, it should be on a sticker on the side of the battery
Never buy a pre-filled battery for this very reason.

If an AGM battery is pre-sealed, do not buy it. Period.

Only buy AGM batteries that come with the fluid separately. You fill and seal, wait 30 minutes, and do the initial charge. Then you have a 100% brand new battery that has not sat on the shelf.

Deka @ AutoZone, and EverStart AGM @ Walmart both come with the fluid separate. The EverStart is made by YUASA. Deka is a known quality brand of battery, too.
 
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Just picked up a SH-775 "Series" R/R for my Vulcan (pending install). Vulcanizer have you resolved the "current drain" issue you mentioned? How is the SH-775 R/R running currently?
 
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