[TripleKing]

Are you checking at the orange feed on the alternator? Should read actual bat voltage. That wire come from the fuse box, you'll need to clean that also. I've found that wire very corroded at the fuse box.

Cleaned all the connectors at the fuse box. Got the make spades shiny. Cleaned the fuse recepticles. Started her up. At idle, I was down to 14. Then it was 14.5. Finally 14.8. I watched it happen It settled at 14.8

Maybe some of it was due to a battery that was no longer fully charged. However, since its does respond to wire connection improvements, I have to think that is the source of the trouble.

If I was sure it would stay under 15 I would leave it as most batteries can tolerate up to 15 volts, these days.

Any other suggestions, other than changing the regulator (which I don't think is the problem)?

[Kreylyn]

Cleaned all the connectors at the fuse box. Got the make spades shiny. Cleaned the fuse recepticles. Started her up. At idle, I was down to 14. Then it was 14.5. Finally 14.8. I watched it happen It settled at 14.8

Maybe some of it was due to a battery that was no longer fully charged. However, since its does respond to wire connection improvements, I have to think that is the source of the trouble.

If I was sure it would stay under 15 I would leave it as most batteries can tolerate up to 15 volts, these days.

Any other suggestions, other than changing the regulator (which I don't think is the problem)?

A final option, run a fused relay mod directly from the battery positive to the input of the alternator, and bypass the entire electrical system. You could even add in a volt meter (even if temp) to make sure your aware of issues in the future if they occur.

Krey

[TripleKing]

A final option, run a fused relay mod directly from the battery positive to the input of the alternator, and bypass the entire electrical system. You could even add in a volt meter (even if temp) to make sure your aware of issues in the future if they occur.

Krey

OK, is there a thread discussing a fused relay mod for the 750 pre-Kat? What relay? 10 amp fuse? Run from battery positive and splice into orange wire?

[Kreylyn]

OK, is there a thread discussing a fused relay mod for the 750 pre-Kat? What relay? 10 amp fuse? Run from battery positive and splice into orange wire?

I don't know that a thread here has listed the mod, other than me mentioning it before.

It's the same setup as the coil relay mod, only the output replaces the orange wire input to the altenator (instead of a coil), and uses the orange wire to power the relay switch.

There is another website I just ran across though that has this discussed...

http://oldskoolsuzuki.info/archives/tag/1127

scroll down to the "Altenator Overcharging problems" section.

Krey

[TripleKing]

I don't know that a thread here has listed the mod, other than me mentioning it before.

It's the same setup as the coil relay mod, only the output replaces the orange wire input to the altenator (instead of a coil), and uses the orange wire to power the relay switch.

There is another website I just ran across though that has this discussed...

http://oldskoolsuzuki.info/archives/tag/1127

scroll down to the "Altenator Overcharging problems" section.

Krey

OK. Just need to figure out which relay and where to source it.

It looks as though the relay mod got it down to the mid-14s. I am almost there was fluctuating between 14.5 and 14.9. Before I go hacking things. I m going to try cleaning, one more time.

[TripleKing]

I don't know that a thread here has listed the mod, other than me mentioning it before.

It's the same setup as the coil relay mod, only the output replaces the orange wire input to the altenator (instead of a coil), and uses the orange wire to power the relay switch.

There is another website I just ran across though that has this discussed...

http://oldskoolsuzuki.info/archives/tag/1127

scroll down to the "Altenator Overcharging problems" section.

Krey

OK, I cleaned some more. This time I cleaned the fuses themselves and (finally) hooked up my son's digital voltmeter. His meter is now reading 15.25-15.35 at idle, but at anything above 3000 RPM, it sinks to 14.9-15.1. I found that a bit odd.

[RobertTravis]

RE: http://oldskoolsuzuki.info/archives/tag/1127 as per Krey's advice

Alternator overcharging problems, oil-cooled engines By Katanamangler 28th June 2015

Right then ive got to the bottom of this problem and i bet most oil coolers have got this problem thanks to stuart who is a very clever electrical engineer/design.

Suzuki have tried to be clever using a closed loop design which may work when everthing is new perhaps.

Out of alternator are two leads the main power to battery and the other is the ignition feed to alternator which is trigger to turn reg on.
Problem here is voltage drop on the trigger wire, ive measured half volt purely at ignition switch, suppose age takes its toll. ive got further .3 volt loss through wiring and joints i can tell you the connectors are clean and look good.
So alternator battery lead reads say 12.6 volts (engine off) ignition lead reads 12.5 volts but lights on this drops to 11.5 volts where the battery lead reads 12.3 a drop of .8 through switch and harness, so when running when lights are turned on alternator compensator by ramping up output to 15.4 volts which cooks the battery.

Solution:
Remove ignition feed wire to the alternator and use it to power a relay (switch side) the ignition wire out of alternator straight to positive on battery via the new relay.
Result constant 14.3 volts depending on battery state no matter whats on or off, result.

You have to connect via a relay as the reg would drain the battery in no time as this is trigger to turn reg side of circuit on as its a basic deign not like car 1 wire systems where the actual rotation of alternator triggers it on.

In the past ive destoyed batteries for no reason luckily the powerful little gel battery has lasted 3 years but at least now know the reason why, this has got to affect a lot of bikes this sort of age pointing bto reg when actually its working correctly.
Hope this is of i must also do a right up on cvs and good design change, to stop emulsion tubes wearing out.

Ignition wire from alternator ( to work out which of two wire this is it will be the wire that only has 12 volts on it when ignition is turned on, ie black wire on multi meter to earth red on meter prod each of cables in back of plug)

Cut this wire, the one coming from alternator now connect to positive on battery via a relay.
The other side of cut ignition wire coming out of loom connects to the switch side of this new relay obviously the other side of switch side goes to earth.
So when ignition is off relay is open so connection of battery to ignition wire on alternator and visa versa.




Just one thing: first i tried with a cheap relay, it had a difference of 0,2V on the switched wires, so it charged 14,7V. Then I got a better relay (no difference measurable) and it charges perfectly.

..

[Kreylyn]

OK. Just need to figure out which relay and where to source it.

It looks as though the relay mod got it down to the mid-14s. I am almost there was fluctuating between 14.5 and 14.9. Before I go hacking things. I m going to try cleaning, one more time.

Online or auto parts store. They will have 4 and 5 prong auto relays on the shelf.

There are even kits avail to make it a cleaner/more permanent install setup.

https://www.summitracing.com/parts/prf-80136?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-painless-performance&gclid=CKH-t7eQr9QCFYOFswod-hABCw

You could probably source the parts a little cheaper though if you ordered them separately, but it's got some ideas to consider.

Krey

[GSXFJim]

That is true, I put my lithium battery in the fridge during the hot summers, they don't like heat.

The Shorai batteries like the heat actually, in cold conditions they recommend switching the ignition to the ON position for 20 seconds or so before starting.
The Lithium batteries are just the opposite of lead acid units, the resistance goes down as they heat up under load, lead acid units the resistance goes up as they get warmer under load.

[TripleKing]

OK, before hacking things up with the relay mod, I wanted to be certain of my connections. Here is what I have found:

The red wires at the connector under the tank have the exact same voltage as the battery. This is true on either side if the connectors. My orange wires in the same location have just a 0.2 volt drop. This should not cause the alternator to run at 15.2-15.3, where it is now. The last connction I have to check is the one at the alternator, but for the life of me, I cannot find it. Based on a parts schematic, it looks as if it connects quite a bit away from the alternator/regulator. Where might that connector be?

Making in worse is that I am red/green color blind. Thus, I don't see some shades of red or orange very well.

Thx,

Tom

Edit. OK I have it in the high 14s, with an occasional blip to 15. The Kat is not ridden much. I can live with that.

[ZookRick]

The connector is probably under the carbs near the battery. It is two wires, one red and one orange, one wire bigger than the other.

[TripleKing]

If it is there, I won't be able to reach without moving the airbox. Ugh!

I have it down to about 14.9-15. I think I will take my chances. Took me 2-years to cook my battery near 16 volts

[92xjunker]

The wires you need to deal with are on the right side of the bike. They will have a braided cover. No need to pull the airbox.

[TripleKing]

The wires you need to deal with are on the right side of the bike. They will have a braided cover. No need to pull the airbox.

Zip-tied to the right frame of my Kat is the tape-covered harness that goes upt toward the battery box The only connectors on the right side sit in front of and to the right of the batter box, at the same level as the battery box. Don't see any red or orange wires there.

[TripleKing]

The wires you need to deal with are on the right side of the bike. They will have a braided cover. No need to pull the airbox.

OK found it. Red gets what the battery has, orange is a volts down. When running, same, as expected. Orange gets what the battery has less .02 at all connectors except the one nearest the alternator, which is less 1.1 volts. Thus, my problem is in the wire itself, between the connectors under the tank and the one near the alternator.