GS500 charging issues

[jac27808]

Hi all,

I recently bought a Suzuki GS500 (02 reg) and I've been having problems with the battery. Initially I thought the battery was at fault however I've replaced this and still have issues.

If the bike is not used for a few days the battery has little charge left and when i go out for 20 miles rides it doesn't appear to be charging at all. Actually, the bike frequently cuts out towards the end of these rdies and then I can't get it started again due to dead battery.

Using a multimeter, when the bike is all off, then the battery has a good voltage. When the bike is turned on and idling the voltage drops to 12.4(ish) V and this does not increase when I increase the revs.

I've followed the steps to check the R/R from the John Bates charging circuit test. At step 16, my multimeter reads OL rather than any voltage (assuming I'm using it correctly). I've also noticed that the yellow wires which connect to the R/R become fairly warm to the touch. I'm assuming these yellow wires are R/R but they could be the stator?

I'm not mechanically sound particularly but I don't really want to pay a fortune for a mechanic to test things, any help would be greatly appreciated.

thanks,

[WD Forte]

Who is this bates you speak of?
Why should we all know of him/it?
How do we know it's accurate or useful?

Anyway, stator test, quick and easy and if you have a meter
Just remember, Very high, Very low OK?

Disconnect plug with 3 yellow wires coming from stator

You want to see very high resistance ( mega Ohms) between each wire and the stator body if out of the engine,
or the engine case/frame ground/battery neg terminal if in situ.
Anything less than at least 1M Ohm on each wire is highly suspect

OK?
Next set the meter to its lowest resistance setting and short the probes together.
This will tell you the resistance of the leads
now select a lead and read between that and the other two
then do this with another lead
Remember to subtract the lead resistance from the reading/s
You want see around 1 ohm or less ideally
Anything more is suspect

By now I usually know if the stator's OK or not
but you can do an AC voltage test between pairs of wires if you want
I'd expect to see say 16-20VAC at tickover going up to 70VAC plus more maybe as I rev it.

If it meters out Ok I move on to testing the RR

(I could have tested mine and be back indoors shouting at the telly
in less time than it's taken me to write this.)
____________________
bikers smell of wee

[jaffa90]

Have you 3 yellow wires from the alternator?
If so what 3 x a/c readings have you using 1+2 wires/ 1+3 wires and 2+3 wires with engine running?

[P.addy]

Instant response is get rid of the GS500.

However where abouts are you based? I'd suggest simply testing the stator wires with + into the wire from stator and - to the frame on a shiny non painted area. If you see zero then something's broken

[jac27808]

Testing 3 yellow wires from stator vs ground I get OL on my multimeter.

shorting probes together gives me 0.5. Reading between the leads gives 1.1, 1.2 and 1.2. So less than 1ohm when taking the resistance away.

The bates guide I'm following: https://bbburma.net/Documents/JohnBates_ChargingCircuitTests3.pdf

I've taking a bunch of measurements and maybe the R/R is fauty?

Stator current (AC) at 5000 RPM between leads:
65v, 66v and 65v

The measurements I've taken for the R/R all appear to be too low according to that guide and others I've found. The R/R on my bike has 3x black wires that connect up to the 3x yellow wires of the stator. I've done the R/R measurements (no 14 - 18 below) on the black wires coming from the R/R is this correct?

All measurements according to the bates guide:
1. All off = 12.88 / 13.12. Idle (1200RPM) = 13.9. 2500 rev = 14.2. 5000 rev = 14.15
2. 14.2
4. 60mv
6. 48mv
8. y1-y2 = 1.5 ohms. Y1-y3 = 1.5 ohms. Y2-y3 = 1.4 ohms
10. OL for all
12. y1-y2 = 65v. y1-y3=66v. y2-y3 = 65V
14. Red – y1 = 498mv. Red-y2 = 510mv. Red-y3 = 513mv
16. OL for all
18. y1 =514mv. Y2 = 512mv. Y3 = 510mv

Thanks for the help so far.

[jaffa90]

I've taking a bunch of measurements and maybe the R/R is fauty?

Stator current (AC) at 5000 RPM between leads:
65v, 66v and 65v
I agree.

[jac27808]

All of the readings from the R/R are consistent - which I thought meant that it was OK?

The connection with the Red and b/w connects to the cable coming from the R/R and looks damaged/corroded (pic). The yellow wires that also connect up to those coming from the R/R get fairly hot to the touch. Could the R/R be OK and this connection be the issue?

[img][/img]

[P.addy]

Well having shit corroded connectors is doing you absolutely zero favours here.

I'd get that all cleaned up, if you are receiving weird/no readings from the stator, thats odd, but would point to that. Have you taken a look at the stator itself, last time I had a cooked stator, it was literally burnt.

[jaffa90]

He says he`s getting good readings from the stator & R/R.

[P.addy]

Thinking back to mine, my main fuse was proper green and my battery refused to charge.

[jac27808]

I've already replaced the fuse although it looked OK.

I'll see about replacing the connection and see if that fixes things.

thanks for the input so far.