Smokin' hot rectifier

[Anonymous]

On my way home this afternoon, my engine and all electrics suddenly died. I coasted around a corner, and checked the main fuse. Sure enough, it had blown. A few seconds after I replaced it, I saw smoke coming from under the battery. I immediately pulled the fuse and pulled the battery and right side cover. I couldn't find anything that looked like it had been burning, but the rectifier (that's the finned unit under the battery box, right?) was as hot as a steam iron.

Is it common for these things to act up like that with no warning symptoms? Am I correct in assuming that my rectifier is toast? I recall a post about substituting a Honda unit as a replacement. What do you all recommend?

 

[duaneage]

The RR could be bad but I think there is a short somewhere . Unhook the battery Red cable, unhook the red lead from the RR as well, then use a meter to measure resistance between the main fuse ( you need a good fuse for this test) and the ground (engine case). With the key off it should be very high, no shorts. Turn on the key (remember the battery is out and the engine is off) and see how low it goes. IF it goes real low, like 0.0 ohms, then you have a short. Normal should be around 2 ohms with EVERYTHING turned on, of course things like turn signals vary the load a bit. Remove the fuses one at a time to see if you can find a short. If you see a 20 amp fuse where a 10, 5 or 15 amp fuse should be I would think you found a problem as well.

I would not replace the RR until you are absolutely certain there is not a short in the system. Doing so will mean the end of a new RR, even a Honda model. Another trcik is to remove all fuses except the main one that allows the engine to start. If the voltages are good adn the fuse stays put you are not going to need a RR.

Resist the urge to just replace the RR or stator, get a meter and check for shorts. The "fuse remove" method is a safe and cheap way to troubleshoot a problem down to a specific area. Look for Orange wires. These are the high current power wires that feed stuff like brake light switches, turn signals, etc.


BTW - I think I recall a post earlier this month about adding 110 watts of lighting on an 850. 8-[

 

[Anonymous]

Thanks for the info. I'll try it out.

I did try 110 watts, but that was very briefly and took place 20 years ago, so I don't think it's related to this.

I do have a battery tender hooked up, so I can trickle charge my battery in place on the bike. Do you think that would be a factor? I didn't, since it's connected directly to the battary itself.

 

[SqDancerLynn1]

The reg is toast . Disconnect the reg, Charge the battery & take it for a ride. If it does not blow the fuse. Check the stator & replace the reg

 

[flyingace]

Is your headlight working? I understand from the elec. info that 1/3 of the output from the stator goes directly to power the headlight. If the headlight isn't shining, all the extra charge goes thru the R/R's heat sink. Maybe this is why it's hot?

If I'm wrong about this, please educate me

Ace.

 

[Anonymous]

When I replaced the fuse, I tried turning on the ignition, and none of the lights came on. Once I saw and smelled the smoke, I shut it off and pulled the fuse before it blew or the bike caught fire. 8O It will smoke with the ignition off, too.

 

[flyingace]

Certainly sounds like a short to me.

 

[duaneage]

The RR and Battery are in whats sometimes called a primary circuit. There are no fuses normally and the wires are really big, like 10 gauge or even 8.
Unplug the red wire from the RR and see if there is a short betwen the red wire coming out of the RR and the frame of the bike. If so, RR is bad. IF not start following wires.

At this point the RR may have been damaged by this little issue, I would replace it no matter what you find just to be safe.

 

[Guest]

Rectifier question

Rectifier question

Is your headlight working? I understand from the elec. info that 1/3 of the output from the stator goes directly to power the headlight. If the headlight isn't shining, all the extra charge goes thru the R/R's heat sink. Maybe this is why it's hot?

If I'm wrong about this, please educate me

Ace.

Just got my 83 GS1100E running today, would intermittently blow the main fuse, rectifier was getting HOT! Before I go buying one, I read this post about the headlight getting 1/3 of the power. Well, my headlight is NOT THERE, as in disconnected, as in I bought one on eBay, and I'm waiting for it to get here! The headlight bucket is just sitting there empty right now, but the wires aren't touching or anything. Could this be the problem, the absence of ANY headlight?????

 

[frosty5011]

Just got my 83 GS1100E running today, would intermittently blow the main fuse, rectifier was getting HOT! Before I go buying one, I read this post about the headlight getting 1/3 of the power. Well, my headlight is NOT THERE, as in disconnected, as in I bought one on eBay, and I'm waiting for it to get here! The headlight bucket is just sitting there empty right now, but the wires aren't touching or anything. Could this be the problem, the absence of ANY headlight?????

No, 1100ED doesn't route the lead through the headlight. Suspect a short / bad connection somewhere in the system as the culprit.

 

[knotzilla]

I got a scare the other day while doing maintenance on my bike. I bought the 850g last October and rode it up to now with no problems. For some unknown reason I decided to check the main fuse. To my astonishment I found that the previous owner had used a 30 amp main fuse. I replaced the fuse with a 15 amp and everything still worked normally. I'm just lucky that nothing seriously shorted and melted with the 30 amp. Ted

 

[Road_Clam]

On my way home this afternoon, my engine and all electrics suddenly died. I coasted around a corner, and checked the main fuse. Sure enough, it had blown. A few seconds after I replaced it, I saw smoke coming from under the battery. I immediately pulled the fuse and pulled the battery and right side cover. I couldn't find anything that looked like it had been burning, but the rectifier (that's the finned unit under the battery box, right?) was as hot as a steam iron.

Is it common for these things to act up like that with no warning symptoms? Am I correct in assuming that my rectifier is toast? I recall a post about substituting a Honda unit as a replacement. What do you all recommend?

There has been a ton of discussions on "hot" running R/R's. A lot of the heat seems to stem from poor grounding of the R/R. Run a ground wire from the r/r case, right to your engine case. I have severall grounds from the engine case, to all the electrical components on that rubber mounted panel. My r/r gets very warm, but thats it, nothing serious.

 

[Guest]

Thanks for the response guys! First thing I'm going to do is go through all the wiring and clean everything up, when I got the bike home from it's 4 year hiatus in the back of an old shed, I gave it a initial cleaning with a bottle of WD-40. I may have accidentally gotten some of the wires "wet" with the WD, so that may be what's causing the short, or bad ground. I've got some time to work on it today, the carbs are off and currently soaking, so I should be able to get the wires all cleaned up today. Also have a new headlight in the mail, it currently has none, and I noticed a couple of other wires not connected, I know one set was for the tank/gas gauge, I'll figure out what the others are and get them connected, or taped off...........this is a great site, can't wait to get my GS on the road again!