T500L Losing volts

General discussion about Street two-stroke Suzuki motorcycles.

Moderators: oldjapanesebikes, H2RICK, diamondj, Suzsmokeyallan

Post Reply
User avatar
malky
On the main road
Posts: 114
Joined: Tue Mar 15, 2011 11:52 am
Country: UK
Suzuki 2-Strokes: GT750A T500K T500L GT500A GT185A RV125L COLLE
Location: south wales uk

T500L Losing volts

Post by malky »

Hi all,
my T500L is only getting 7volts at the tail/brake lamp connections - to me this seems like a big drop,I have cleaned all the terminals and earth connections but that hasn't made any difference - is this normal or am I looking for a fault that is not there - I am using the twin bulb set up from an earlier bike fitted with LED bulbs but without the engine running there doesn't seem to be enough power to light the stop lamps .
cheers
Mal.
User avatar
jabcb
Moto GP
Posts: 4242
Joined: Mon Dec 13, 2010 4:32 pm
Country: USA
Suzuki 2-Strokes: 69 T350 thru 75 GT750
Location: southwestern Pennsylvania

Re: T500L Losing volts

Post by jabcb »

Something is wrong. The voltage drop from the battery + to the bulb + should be something like 1-1/2 V.

Make sure your battery is fully charged. No point in ruining a battery while you figure this out.

Use a multimeter & a wiring diagram. Check the voltage at various points between the battery + & bulb + to see if you can find the big voltage drop.

If your bike has a kill switch, set it to off. This way you won’t overheat the coils & the battery charge will last longer.


Wiring diagram is here:
viewtopic.php?f=29&t=4743
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more

Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
dollydog
Yeah Man, the Interstate
Posts: 630
Joined: Fri Aug 11, 2017 7:09 am
Country: england
Suzuki 2-Strokes: several gt250 ramairs

Re: T500L Losing volts

Post by dollydog »

i've had this on different suzukis i've been refurbing and every time it's been an earth connection. have you cleaned and checked ALL the earth connections? :D
cheers, dd.
GTS250 road registered. TS250 engine, Ramair frame.
GT250 big bang road registered. Both pistons fire the same time. USD forks.
GT285 road registered. Overbored - 58mm and TS125 +2 pistons fitted.
GT10 road registered. '65 T10 engine, GT250 frame.
User avatar
malky
On the main road
Posts: 114
Joined: Tue Mar 15, 2011 11:52 am
Country: UK
Suzuki 2-Strokes: GT750A T500K T500L GT500A GT185A RV125L COLLE
Location: south wales uk

Re: T500L Losing volts

Post by malky »

Thanks for the input guys - have checked and cleaned all the earths and I'm pretty confident that they are ok ,I have run a separate earth lead directly from the battery to the frame as a belt and braces step but its still the same
User avatar
malky
On the main road
Posts: 114
Joined: Tue Mar 15, 2011 11:52 am
Country: UK
Suzuki 2-Strokes: GT750A T500K T500L GT500A GT185A RV125L COLLE
Location: south wales uk

Re: T500L Losing volts

Post by malky »

problem solved - faulty new battery - substituted a 12v power source and getting 11.75v on both live contacts so just ordered a new AGM type battery to go on there :up:
User avatar
jabcb
Moto GP
Posts: 4242
Joined: Mon Dec 13, 2010 4:32 pm
Country: USA
Suzuki 2-Strokes: 69 T350 thru 75 GT750
Location: southwestern Pennsylvania

Re: T500L Losing volts

Post by jabcb »

The stock voltage regulator is pretty lame. It’s considered ok for the voltage at high rpm to be 16V.

You should use a modern rectifier/regulator with modern maintenance free or AGM batteries.
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more

Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
User avatar
johnakay
I likes them jubblies
Posts: 2365
Joined: Wed Oct 15, 2008 11:19 am
Country: UK
Suzuki 2-Strokes: bike

Re: T500L Losing volts

Post by johnakay »

notice your in wales.
try rexspeed reg/rec all in one unit. .
I just bought one £60
If I wanted to make a life-long career out of
working with the mentally retarded I would
have opened a Harley Davidson Dealership
Post Reply