Electrical problem.....bike not running properly with lights

[ruddiger]

hi all,

i had a problem a while back with a wire from the main harness snapping and killing the starter motor. i replaced the wire and the starter runs fine BUT now when i have the lights on on the bike the bike struggles & splutters(same as when your out of fuel) when running under 3k revs........any ideas?
i checked the wiring and nothing seems out & it only happens when the lights are on.......

[DonTZ125]

The struggling engine with the lights on is the key - either your battery is failing (possibly due to whatever happened before) or your voltage regulator failed such that it is UNDER charging. This last is rare, but vastly preferable to the usual mode of OVER charging and frying your lights, harness, and ignitor box.

Search for charging system troubleshooting; there's a good chart and more than a few threads.

Good luck

[thatkid]

The struggling engine with the lights on is the key - either your battery is failing (possibly due to whatever happened before) or your voltage regulator failed such that it is UNDER charging. This last is rare, but vastly preferable to the usual mode of OVER charging and frying your lights, harness, and ignitor box.

Search for charging system troubleshooting; there's a good chart and more than a few threads.

Good luck

The excellent chart V-R trouble shooting Flow chart <<< click there

Follow that, then check the charging rate. Then with the headlamps switched on, Watch the voltage drop, if it's significant either the VR is toast or your battery could be. You could also have poor/corroded connections (Brighton UK?) hows the rain treated you lately?

If your VR is toast, and you have the old crap VR fitted (which are fitted to 125 motorcycles, with no fuel pump and far less electronics) You should upgrade the VR, The simple modification is listed here r6_voltage_regulator_conversion

Good Luck
Mal.

[ruddiger]

Hi guys,
cheers for the help.
I will go through the flow chart and see if i can find something from that.

I have already converted it to the R6 VR...under a year ago so hopefully thats still good.
Yeah Mal i think it could be to do with the weather....20 year old wiring....cant be great in rain, and the problem with the starter was the that the wire corroded.
Just replaced the blade but the housing was not in the best condition....

What is the white plastic (9 pin i think)connector that goes to the relay called?
Been trying to search online for a replacement but not coming up with anything other than replacing the loom and may end up with the same problems....

[thatkid]

Yeah Mal i think it could be to do with the weather....20 year old wiring....cant be great in rain, and the problem with the starter was the that the wire corroded.
Just replaced the blade but the housing was not in the best condition....

What is the white plastic (9 pin i think)connector that goes to the relay called?
Been trying to search online for a replacement but not coming up with anything other than replacing the loom and may end up with the same problems....

I'm assuming you mean the connector to the main relay (Black box/relay located behind the left rear side panel) if so it's actually an 11 pin connector, but only 10 are used (10 wires).

Those female spades can be removed with a small watch makers screwdriver (there's a tab holding them in). When one of mine corroded/snapped I bought these off eBay Female spade terminal 2.8mm with tab (10 off) 2923T then soldered the replacement in place. Low and behold the British weather corroded them again

There's many threads here regarding dielectric grease (thanks reelrazor), I'd never heard of the stuff & it's not widely available in the UK , after countless hours of searching, I found this was the real deal & the most economical available in the UK http://www.motorwayshop.co.uk/shop/prod ... ector.aspx I've pumped that into all my connectors, I think my electrical woes are now a thing of the past

One more thing, the broken wire was it Blue/White? If so, and your still having trouble starting her up. (until you get replacement parts)

Ensure the bike is in Neutral (safety switches WILL be bypassed) Ignition ON. The Starter solenoid (located behind the battery box) disconnect the Blue/White wire connection. The Blue/White wire from the solenoid (not the harness) short that to ground (battery negative) she should crank & fire up.

Good Luck
Mal.

[ruddiger]

I tried the flow chart and the VR is fine and its giving the correct voltage but as soon as i switch the lights the voltage drops and keeps dropping even as the bike is being revved, i checked the wiring i did on the connection and its not crossed and seems fine, the water level in the battery is low in a couple of the cells but not under minimum, will top it up anyway and see in it makes a difference, the battery does look pretty old so could need replacing anyway....

Cheers for the links Mal, yeah i heard about the dielectric grease but couldnt find it over here, good find!
yeah i think ill order the connectors and rewire as much as i can, the bike seems to have no end of electrical probs & they are always the hardest to find!!
Yeah it was the blue/white wire that snapped but i managed to get it back in so the starter is working fine...when the battery works!

[DonTZ125]

*scratching head* What wattage rating is on your headlight bulbs? If you're supposed to have 2x 35W, and you've got 2x 75W or something mad like that...

[ruddiger]

hmmmm not sure what the bulbs are but they have been working fine for over a year,
im thinking its gotta be a frayed or crossed wire somewhere....

[thatkid]

You should check every connection on the charging system, Battery terminals, the Red cables on the solenoid, There's a single White connector in the Red wiring from the solenoid to the main fuse, also pull the main fuse out (it could be corroded). If any of those are corroded/poor connections, the vibrations from the engine revving could further degrade them. Then there's the engine ground.

Also have you charged the battery on a trickle charge?

[ruddiger]

Cheers man will check them when i get home.
No charger at the moment but should be able borrow one tomorrow.

Thinking its prob a wiring problem because the bike is perfect until i switch the lights on, as soon as i run it with lights i get about 10 mins then if i shut the bike off the batt is too dead to start again, bump start it and run it for a few mins(lights off) and the battery is full again.......

[DonTZ125]

You've got a major short somewhere. Mawler's not wrong on everything to check, but given the symptoms I'd check the switch cluster and loom to the headlights first. If it's sucking down that kind of juice, you're quite possibly risking a fire!

[ruddiger]

ok,
checked the connections that are easy...ish to get to and all seem fine,
it looks like its down to the headlights, as i said before its reading the correct levels when no lights are on and when the tail, brake and dash lights are on but as soon as i turn on the headlights the the ampage/voltage drops,with the bike running i removed the fuse and left the switch on and it was fine, i took the connectors off the back of the bulbs and it was still ok.
I changed the bulbs and it drops but not as bad....but again once the bike is not running and the lights are on it keeps dropping....

getting a bit stumped now! if it was crossed wires wouldnt i have the same problem when the bulbs are disconnected?

UPDATE** left the bike ticking over with the lights on and it the voltage/amps(not sure which it is!!) didnt drop under 11.40 which sounds good to me, will get the charger sorted tomorrow and do more tests then

[kilika2]

11.40 I hope is volts.

Also just a little info if you get a charger, don't use one from a car it will over amp the battery and you might boil the electrolytes. Some people will say it's ok but I did it for about 3 min one time just to get me home when I had a bad battery and I could literally see the "water" boiling.

Also if you do it over night take the battery out of the bike. If you leave it connected the tender could feedback into the TDI and you'll have a lot of fun with that. Also the sulfuric gas will eat your paint and metal if it comes out the drain tube.

Didn't know if you knew all this but it's always a good reminder if you are already thinking about something else. Good luck.

Chris.

[thatkid]

11.40 I hope is volts.

Also just a little info if you get a charger, don't use one from a car it will over amp the battery and you might boil the electrolytes. Some people will say it's ok but I did it for about 3 min one time just to get me home when I had a bad battery and I could literally see the "water" boiling.

Also if you do it over night take the battery out of the bike. If you leave it connected the tender could feedback into the TDI and you'll have a lot of fun with that. Also the sulfuric gas will eat your paint and metal if it comes out the drain tube.

Didn't know if you knew all this but it's always a good reminder if you are already thinking about something else. Good luck.

Chris.

Good call

The recommended maximum charging rate (amps) is 10% off the battery's rating. The 600 battery is rated @ 12 Amp Hours = A Max charging rate of 1.2 amps. Car chargers are usually around 5 amps. A car booster charger is a definite NO NO! it will kill your battery in minutes.

Mal.