Wierd Low Voltage Problem

alot of bikes have them there. there is nothing wrong with the location. some of us gen2 guys are relocating them there.

to the OP get the service manual and check all the pins on the regulator/rectifier per manual.

By "alot of bike have them there," you mean the default position should be fine?

I have the rectifier off and will be testing it shortly. I have a very basic volt meter that only tests a live circuit and continuity. I'm sure Home Depot will have a better one. What exact setting or feature should I be looking for on the new one, in case one of you guys gets to this before I leave?
 
By "alot of bike have them there," you mean the default position should be fine?

I have the rectifier off and will be testing it shortly. I have a very basic volt meter that only tests a live circuit and continuity. I'm sure Home Depot will have a better one. What exact setting or feature should I be looking for on the new one, in case one of you guys gets to this before I leave?

yes factory setting would be fine, gen 1 or 2.

i havent read or checked the gen1 service manual for reg/rectifieir testing. but to check gen 1 it needs to read diode - voltage.

the diode symbol looks like an arrow with a line coming though it.

find the service manual and in charging system there will be a section on how to test it.
 
Alright, here's what I got. I wrote "N/A" where it should have gotten the meter's battery's voltage because nothing registered. I guess it just won't give a reading if the path is unrestricted on a diode test.

Sorry if the writing is a bit messy. I just jotted it down right fast. Several appear to read above spec. Do you guys think it's bad?

rectifier.jpg
 
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I just retested some of them out of curiosity, and I'm getting between 1 and 2 hundredths higher than last time across the board. So now the B's are more than 2 tenths above spec (1.4v).

I'm assuming this means it's bad, but can someone explain to me exactly what is happening? Is it allowing more voltage to drain from the battery than is being replaced, so the battery is running dead? Or what's going on?

Thanks.
 
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Well I just got the new R/R in. The B pins that aren't supposed to test over 1.2v and tested at 1.39-1.4 on the old one are testing at 1.77 on the new one..

So I guess it wasn't the R/R..
 
Alright, update:

I started testing the charging system myself even though that one shop in the OP said it was fine. I had no accessories hooked up to the battery except the Power Commander, which is obviously necessary unless I unhook it from the fuel injectors.

So, the battery only dips down to around 10.5v when started. That's good. It sat at about 14.4 to 14.5v at idle though, which I thought it was supposed to sit at mid-13's when idling. It stayed at mid 14's even when revved to 5k RPM. But low and behold a minute or two later, it's like the charging system just quits. It drops back to normal battery voltage, about 12.7, then slowly falls, falls, falls. I'm obviously just running off of battery. This would explain why the shop said the charging system tested fine the couple minutes he had it running, but then it happened again once I got back on the road.

Right as I was about to cut it off, I saw a little steam and a little coolant started to drip from the bottom of the bike and the temp went red. I thought a fitting may have backed off or something. I took the fairings off today, and I didn't notice coolant anywhere except for on the oil cooler under the reservoir overfill tube. So I'm assuming the bike just overheated from being revved up to 5k RPM in this over 100 degree heat, and what was in the reservoir boiled out? I just want to verify this with you guys that nothings wrong before cleaning it off and getting the fairings back on.

So anyway, I topped off the coolant, and wanted to verify the voltage thing I found out yesterday. It did the same thing. Charges fine for the first few minutes, then it slowly drops off as if it's just running on battery.

Does this sound like the R/R is failing once hot?

Thanks.
 
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My buddy's 08 is doing this EXACT same thing right now. We ordered a new r/r hoping it's going to fix the issue...maybe not. We havent received the new one in yet. I can't imagine what would cause this other then a r/r problem....I am not sure if the gen 2s charge the battery back through the starter relay like the gen 1s but if so, maybe the issue is in that area....

You can always run the pos and neg wires from the r/r directly to the bat terminals to bypass the harness and starter relay which usually improves the charging but.....shouldn't have to do that kind of stuff on a new bike...
 
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Just thought I would give a final update.

I had checked all the wiring I could think of. Nothing seemed to be fried or shorting anywhere. I could never test the stator putting out less than it should, so I decided to just go with a new battery and the R/R since I already had it.

I just took the exact same 400 mi. trip as in the OP, and the whole thing went off without a hitch. So it was either a bad battery or a failing R/R when it heated up. This coming after each of those items seeming to test well.

I put some Engine Ice in it just before going too.

Anyway, thanks for the guidance!
 
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Im havin issues with my bike. Ive had a few hard times trying to start my bike up but once i get it on, while the bike is on sitting there the voltage is up in the 13s 14s but once i accelerate it the voltage starts to drop low i let go let it sit and the voltage starts to rise again. What might the problem be?
 
@joker1300 welcome to the forum.

Do you have a service manual? This sounds like charging components may need replacement. With a multimeter run the tests on the alternator, rectifier, and leakage. What is the age and condition of the battery? It should be charged before running any tests.
 
Im havin issues with my bike. Ive had a few hard times trying to start my bike up but once i get it on, while the bike is on sitting there the voltage is up in the 13s 14s but once i accelerate it the voltage starts to drop low i let go let it sit and the voltage starts to rise again. What might the problem be?
Welcome,

The thread you are in is from 2010.....starting a new one would have been a good idea so people respond to you....

What year is your bike?

It sounds like a regulator to me...
 
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