Weak Charging system output on a 1979 GS550L

[IceMan17]

Ok, so I have a 1979 GS550L (with 24,000 miles on it, and it was last tabbed in 05 then sat in a barn for 3 years) which I got for $100 about a month ago. I have cleaned the carbs and got it running but I noticed that the blinkers wouldn't blink. I put a Voltmeter on the battery and got 11.9 volts at idle. The battery itself puts out 12.5 when its fully charged so I new something wasn't right. I have tried so many different things that I've started to look for another bike. Basically Just looking at it frustrates me. I am 100% open to any advice that you may give. Also I have a clymers manual and I was wondering if it was stock for mine to have a rectifier/regulator in one unit? According to clymers the 1979 had them seperate.

I have -

1. Performed Stator paper checks and my stator passes.

2. brand new battery

3. brand new Rectifier/regulator

4. Ran all grounds (ones that originally went to the battery box) straight to the negative terminal on the battery,

5. Tested every single wire on this bike to see if they are shorting against the ground or each other.

I get 12.5 Volts at the battery when bike and igition is off. and as soon as I start it with everything hooked up it drops to 11.9 and rises slowly to 12.75 after revving it at 5000 rpms for like 25 seconds. As soon as I disconnect the headlight the voltage goes up to 13 at 1000 rpms and then it will hit 14.2 volts at 5000 rpms and it won't go any higher than that. Any Ideas?

Thanks,
Jake

P.S. Are your blinkers suppose to blink with the bike not running? My don't, they only blink when I'm making 12.6 volts or higher.

[IceMan17]

TTT

P.S. I have looked at all the other charging system problems on this website and none of them have helped me at all.

[Nessism]

When you replaced the R/R did you wire it back into the factory wiring or did you go straight to the battery? Sounds like you either have some bad connections in the system somewhere that are sucking down the voltage or your new R/R is bad.

I installed a Honda CRB R/R into my 850 and wired it direct to the battery with an in-line fuse. Also provided a branch feeding the harness but for the most part, the factory wiring was bypassed which has worked well.

[lucabond]

I had similar problems what I belive is happening is the old wire in the harness is acting like a resistor of sorts and is consuming the power. When you cut off an old bullet connector and you see the wire is black in the insulation that means water has infiltrated the wire reducing it ability to carry current. My blinkers wouldn't work with just the key on untill I put the headlight and "dash" lights on a relay ala the coil mod. By supplying the lights directly I took that load off the harness which left more current for the blinkers and the rest of the bike. The lights draw almost 10 amps and now my blinkers work with just the key on and the headlight and opposite blinker donesn't dim in rhythm to the flasher. I also supplied a seperate ground to the lights. I hope this helps.

[IceMan17]

Thanks guys!

Hey I just got done wiring my RR directly to the battery and Now I'm getting 14.5 volts with the headlight off and about 13.5-14 with it on. It slowly goes down though and drops right back to 12 (not even enough to blink the blinkers) when I turn the blinkers on. Then I gotta rev it until the charge builds back up then it slowy dies again. I think you may be right about the Wiring harness acting as a resistor. Do you have something that I could go by to put the headlights and gauge lights on a relay or what do I have to do to tray that? (i'm not even sure what you mean by relay!) lol

Anyways, Thanks a ton.

P.S. I recently sanded all the old paint off the tank and side covers then applied 3 coats of primer, 3 coats of gloss black, and 3 coats of clear coat to everything and It was all duplicolor automotive spray cans. This was about a month ago. The other day I was putting some gas in the tank and I accidently dripped some onto it and exactly where the gas touched it the paint became gooey and wrecked it. I think this time I'm gonna use some mean paint stripper (cause sanding sucks!) but What would you suggest for paint (want a nice gloss black) that will resist gasoline?

Thanks again!

[PaulC]

Having same charging issues with my 82 850GL. Next step is to do a direct ground from battery to frame.

Related to paint - did similar procedure and from what I've experienced and what I've researched spray can paint doesn't hold up to gas. Most people live with it or get it professionally clear coated.

[lucabond]

Here is the link for the coil mod,

http://members.dslextreme.com/users/bikecliff/images/coil_relay_mod.html

Your headlight is usually on a wire by itself yellow in color it would come from your headlight switch, you would connect this wire to the relay so it gets its power direct from the battery this would take the load off the harness. You would have to get a wiring diagram to see how you running lights are powered and connect that wire to the relay also f you wanted to go that route. A relay acts the same as the starter selonoid when you apply power to it usually low current it closes 2 contacts that are able to handle high current so when you turn on the key the headlights come on. If you need more help just pm me. Good luck
Paul
p.s. check the ground wire from the battery to engine, make sure its clean on both ends and wouldn't hurt to run another heavy wire from the battery to ground.

[duaneage]

Hey I just got done wiring my RR directly to the battery

And you used a fuse in between the two, right? Run an in line fuse of around 20 amps to protect against shorts.

[new_gser]

I had a similar problem with the charging system on my 86 GS550E. I re-did the connection from the negative on the battery to the frame ground (new connectors on both ends) and all is well now.

[IceMan17]

I don't have a inline fuse yet. Where could I get one? Auto parts stores? Walmart? I did have a 8 gauge wire from the battery negative to one of the bolts holding the front sprocket cover on and it helped a little. (maybe .2 volts) I'll rewire that. I have tried a billion times to take the stock ground off of the top of the transmission but there is no room to get any tool in there (unless you want to remove the carbs and airbox!) I did get a screw driver tip in there once but I could not turn that stubborn screw no matter what. I think I'll try the headlight deal for now and see where that takes me.

Thanks a ton!

Jake

[new_gser]

I couldn't get mine off either. I just kept bending the connector until it broke and moved the ground to a bolt that was easier to get to. Put on a new connector and cleaned the paint off around the bolt to make a good connection. When I checked it with my meter I got .2 ohms (my meter won't read zero because of the resistance in the test leads) After I did this I got 14 to 14.5 volts at 4000 rpms at the battery. Before I changed it I was only getting about 12.6 volts.

[new_gser]

I just wanted to add, make sure you have enough extra cable before you break off the old connector if you do it this way. I would also disconnect the battery before you do this, just to be safe.

[IceMan17]

Hey thats a good Idea! I never even thought of that! What bolt did you go to? I had another ground going inbetween the front sprocket cover and the transmission case but then the sprocket cover wasn't on there completley and sense it houses the clutch pusher mechanism deal I didn't want that. Is it best to go to the engine or frame?

Thanks!
IceMan