Pickup Coil Resitance Tolerance

[Mordalo]

Greetings!

I'm trying to diagnose my charging system on a 99 RSV. I check the battery off the bike, and it reads 12.9V. I connect it to the bike with ignition of, it reads 12.9V. I turn on the ignition switch without starting the engine, it reads 12.3-12.4V. When I start the engine, it holds at 12.3V. When I take her to 5KRPM it hold at 12.3V which according to the ever knowledgeable service manual (I've learned my lesson about not reading the manual when troubleshooting...) is bad. It's supposed to be at or around 14V at that RPM range.

So... I now know from that series of tests that my charging system isn't working. I've tested the resistance on my pickup coil, which reads .4 Ohm on both negative leads. The service manual says that it should be between .279 and .34. My Ohm meter is not that sensitive, and doesn't show me 1000ths; it only goes to 10ths. Is .4 significantly out of spec with the .274 to .34 range? I haven't tested the stator yet because I'm waiting for the gasket to come in so I can put it back together again the same day I take it apart. But given the cost of a new pickup coil (I'm looking at about $120USD from my local parts store) I'd hate to replace it only to find out that .06 Ohms is a nominal delta.

 

Thanks!

[pegscraper]

I would call .06 ohms a nominal delta, especially since your VOM isn't very sensitive.

 

When you say pickup coil, this isn't the one that triggers the spark plugs, is it? That coil has nothing to do with the charging system.

 

Are you meaning to check the continuity of the stator?

[Mordalo]

Almost forgot to mention what symptoms started this whole thing... I was riding home from work and going going 60MPH the battery went dead. Speedo went nuts, stereo cut out, then POOF! no power. Got a jump-start and made it home. It took 3 days on a slow-charger to get it full again (btw, battery is 6 months old). A few days later, the same thing happened. Charged it up again, and started putting it on the slow charger every night. After riding it 1 day, the slow-charger had not finished charging it the next morning (13 hrs on the charger). Decided to stop riding it 'til I get this fixed so I don't toast the battery.

[Mordalo]

I would call .06 ohms a nominal delta, especially since your VOM isn't very sensitive.

 

When you say pickup coil, this isn't the one that triggers the spark plugs, is it? That coil has nothing to do with the charging system.

 

Are you meaning to check the continuity of the stator?

 

Well, yes I am talking about the trigger/pickup coil, and yeah I do want to test the stator. I thought that checking the pickup coil seemed kind of odd since it doesn't seem in my small thick head to have anything to do with charging the system but that's the order of testing the service manual recommended and last time I failed to follow the service manual it cost me 2 months and $200 more than it should have to fix what turned out to be a bad side-stand switch.

 

Thanks for confirming that for me. I thought I was missing some basic understanding of how the whole system works...

[pegscraper]

The shop manual does have some strange things in it. I don't always follow it to the letter. Pretty much I only refer to it for bolt torque specs. Keep us posted on what else you find.

[Wanderer]

I don't know, but sounds to me like a bad battery. A similar thing happened

to me with the old Voyager. I had purchased one of the maintenance free

batteries manufactured in guess where? - China. It lasted 3 mos. I thought

I had all sorts of problems. Replaced the battery with a new from Wally World

and no more problems - I traded it this year a year later.

 

[GeorgeS]

Get access to the Rectifyer/Regulator Unit. Remove The Main Plug on it, and Inspect the Pins for Burn Damage !! Or corrosion !!!!!!

 

There Might be a plug between the Stator and Regulator, on your bike, if so, open and inspect that also !!

 

These plugs are Very Common Trouble spots. The pins go bad, and Turn INTO RESISTORS, AND DROP VOLTAGE

[Mordalo]

Get access to the Rectifyer/Regulator Unit. Remove The Main Plug on it, and Inspect the Pins for Burn Damage !! Or corrosion !!!!!!

 

There Might be a plug between the Stator and Regulator, on your bike, if so, open and inspect that also !!

 

These plugs are Very Common Trouble spots. The pins go bad, and Turn INTO RESISTORS, AND DROP VOLTAGE

Thanks GeorgeS, you nailed it. Now I'm even more confused. I replaced the rectifier about six months ago. The wiring harness at that time was pretty burnt so I had to replace that part of the harness. Now, the only connector that's bad is the black wire. everything else looks good. But that black connector is burnt at both the harness and the rectifier itself. luckilly the wire itself looks okay this time so I don't think I need to replace the wiriing again. So, what could be causing the black lead on the rectifier to chronically burn up? I got a more sensitive multimeter and checked resistance on the 3 white wires coming off the stator again and they are at .302 which is within tolerance. So could it be that the stator is causing the rectifier to burn out? Also, is there a way to bench-test the rectifier before I go out and buy another one?

[V7Goose]

Your description of how the problem started certainly sounds like the rectifier/regulator went out. But since you recently replaced it that certainly means you do need to look for a bigger problem.

 

But it is very unlikely that the stator has anything to do with it going bad. The stator in a permanent magnet system like ours puts out max voltage/RPM 100% of the time (so it can't go bad and put out MORE voltage). It is the job of the rectifier to turn that AC output voltage to a nominal 13.5 VDC, and the regulator to determine how much of the available current is needed by the bike's circuits and battery, allow that much to pass, and bleed the rest to ground.

 

Your problem, and the cause of burnt wires, is most commonly caused by bad connections in plugs and to ground. Any resistance causes heat as the current flows through it. You need to pay particular attention to the main grounding points from the wire harness. Disconnect the plugs from the ignitor, reg/rec, etc. and ohm out the wires to verify no high resistance points. You will need to spend time analyzing the schematic to determine all the plugs that you need to find and check, as well as what needs to be disconnected to get a good reading. Find the main ground blocks to the engine and frame and remove them to clean and ensure good contact. Another cause of problems in plugs is loose connections on the pins. If the mating points between the pins have been bent or lost some of the tension that presses the metal pieces together, that allows corrosion to quickly build up, generating the resistance points and heat.

Goose

[Mordalo]

Thanks for the charging 101 lesson. It helps me understand what's going on with the system. It's unfortunate that I already have a stator on order (it's a used one from a salvage bike, only $40), but I'm sure if I hang on to it it'll come in handy eventually. I paid a local Yamaha dealership to replace the regulator because I was going out of town and wanted it running when I got back. That was my bad. They called me and said that there was significant heat damage to the wiring and they had to replace quite a bit of wire. In looking at the wiring harness last night, I realized that the electrical wrapping is new for about 8 inches then it looks like the factory wrapping. I haven't cut it open yet (needed to sleep) but I assume that all they did was splice in a some fresh wiring. It stands to reason then that if the ground-point (or a coupler between the ground point and the rectifier) is not making a good connection, then the problem would stll exist. They replaced the rectifier back in December, so I think it's too late for me to get the shop to accept any liability. At this point I think it's still a bit too early to be mad at them anyway. I think I still have some investigating to do.

 

Thanks again!

[V7Goose]

Your stator may be bad - that certainly would cause no charging, just like a bad rec/reg unit would. Testing with an ohm meter should be very easy to verify it's condition. I wasn't trying to tell you that I thought it was OK, just that it would be extremely rare for it to cause the rec/reg to go bad. From your earlier posts it sounded like you already found signs that your new regulator was bad, so I was focused on that. No matter what, pay really good attention to the condition of the pins and interior of the plug on the rec/reg. I assume the shop spliced a new plug on, so it should be in good shape, but check it close anyway - shouldn't be showing signs of heat this quick! I have over 60,000 miles on my 05 and it doesn't show any heat damage on that plug at all.

 

And December isn't all that long ago, ESPECIALLY if you haven't put a ton of miles on the bike since then. I'd really suggest you go back and complain to them about the problem coming back, even more so if they did the troubleshooting. You have less to complain about if YOU diagnosed it and just told them to change the part.

Goose

[GeorgeS]

As to the Stator, If you measured the AC Voltage On All Three AC output Phases's from the Stator going to Rectifyer, and they are all the SAME , AC voltage which you stated was the case yesterday, Then Assume the STATOR is OK> ( If BAD, one of the three phases, would be Substantially LOWER then the other TWO.

 

 

OK, As to the Bad Black ( ground ) wires you stated in the PLUG, at the Rectifyer.

 

If pins are Damaged, Sorry, you will have to , REMOVE the Damaged Pins from the Plug. This is not real simple. Each PIN, ( male and female ) has a " KEEPER ". You must slide in a Small tool ( usually Flat, thin metal, about 1/8 inch wide ) to release the KEEPER, and to wire with pin should pull out.

 

Your going to have to find replacement male or female connector's to replace the damaged pins.

 

Also, Usually the " FEMALE " pins Lossen up, and make loose ( bad, high resistance connection's ) to the Male pin.

 

Find some Male Pins the same size, and do the " feel " test, slide them in and out of the female pins to make sure there is a Fairly Tight Fit !!!! IF Loose, this can cause ARCHING, and then carbon build up, and this turns into HIGH RESISTANCE. (((( THIS IS THE SAME AS A HEATING ELEMENT ON AN ELECTRIC STOVE--- CONSUMES HIGH CURRENT, AND LOWERS THE VOLTAGE TO THE ENTIRE ELECTRICAL SYSTEM ON THE BIKE. ))) ----- NOT GOOD !!!! -----

 

Also, as long as your working on it, ON the Plug at the Regulator/rectifyer Unit, you can splice into the Black wires which go to Ground somplace on the bike, and run your new black leads to a VERY GOOD Ground fairly close to the Plug.

 

In other words, make sure the Regulator Unit is Well Grounded.

 

Also, Take Resistance Readings " FROM" the NEG Battery STUD, to various Points on the Frame of you bike, ( front to rear ) MAKE SURE YOU HAVE " ZERO oHMS " ie. DEAD SHORT, to ALL POINTS on the Entire Frame of the bike. AND ALL black wires going thru ANY, Electrical Plug on the bike. !!!

 

NOTE:--- 1 or 2, or 3 OHMS --- IS NOT ACCEPTABLE!!!!!!!!!!!!!!!!!!--- NO MATER WHER YOU CHECK, FROM NEG BAT STUD, TO ANY GROUND POINT, SHOULD BE

" ZERO OHMS " !!!

 

Also, use CRC 2-26 ON ALL Electrical Switches !!!!

 

Find the Main 30 or 40 Amp Fuse, between Regulator and Battery, Open it, make Sure NO Resistance across the fuse contacts. ( this is a problem spot on 1st gens, but I'm not sure of this on 2nd gens )

 

Be sure to do the Battery, Full Charge for 6 to 10 hours , ( out of bike ) and let it sit for 24 hours, and then Check the " NO LOAD Voltage " Be sure its NOT discharging " INTERNALLY " !!!!! ( Is the water level Above the Plates ???? ) If a lead acid battery ???

 

DID YOU CHECK YOUR BATTERY CABLE END STUDS, MOUNT POINTS, AND CLEAN ANY CORROSIION ?????

[Mordalo]

Thanks Goose. I think I understand what you're saying. When I took the bike in to the shop the first time I actually didn't troubleshoot it first. I know it can be frustrating for mechanics to have their customers trying to tell them what's wrong. I've seen that cause mechanics to go on wild goose chases (no pun intended Goose). I enjoy working on my bike, but I'm DEFINITELY not a mechanic. I have to remind myself that troubleshooting electrical problems is as much an art as a science. So here's what I think I'm going to do now, and please let me know if you see a flaw in the plan:

 

1. Trace the ground wire off the R/R back to the frame, and ensure it's good all the way. If I'm getting that much burning on JUST the ground wire, there almost has to be an intermittent ground fault somewhere right?

2a. If I find a ground fault, fix it and put everything (except the body trim) back together and test charging again. If I'm getting a good charge, I'm probably done, but I should check the R/R regularly for further signs of damage.

2b. If I find a ground fault, fix it, test it and I'm still not getting a change in voltage at high RPM, I'll replace the R/R FIRST because it's showing obvious signs of being suspect (and it's cheaper than the stator). If after replacing that I'm STILL having a problem, I'll put the replacement stator on. If I'm STILL having a problem, I'll put the bike up for sale and buy one of those little skateboards with those little motors on them and just give up on fixing motorcycles.

2c. If I don't find a ground fault, I'll replace the stator and see if I get a charge. If that doesn't work, I'll order a replacement R/R and keep a close eye on everything. If it still gives me trouble, I trade the bike for a little VW Bug and start making dune-buggies instead.

 

Thanks again everyone for all your help. I'm not very good with electrical stuff, probably because it requires patience, which I've not been gifted with.

[Mordalo]

Wow George, you've just blown my entire weekend...

 

I've just printed out this entire thread and I'm heading down to the garage with my multi-tester and a case of soda (beer would be counter-productive).

 

I'll let everyone know what I find.

[GeorgeS]

Wow George, you've just blown my entire weekend...

 

I've just printed out this entire thread and I'm heading down to the garage with my multi-tester and a case of soda (beer would be counter-productive).

 

I'll let everyone know what I find.

 

IF the PIN is Burnt, that means there was Bad connection between the Male and female pins. ie. Pins did not have a tight fit!! There was resistance between the Male and female pins. ( This high resistance point, becomes a Heating Element )

The problem is Right there at those burnt pins.

 

HIGH CURRENT FLOWING THRU A RESISTOR, CREATES "" HEAT "" The heat creats carbon, as more carbon builds up, the resistance goes higher, makes more heat, its a vicious circle---

 

--- REMEMBER, YOU HAVE UP TO 30 AMPS FLOWING IN AND OUT OF THAT REGULATOR UNIT!!! That why those are Large Size Wires.

[V7Goose]

George has it right on - the heat is only generated where the resistance is, and his detailed description of checking the pin fit was excellent.

 

I will only add one more thing - don't go adding a bunch of new ground connections where they don't already exist. I know that it is unlikely you would, but since we have been talking about making sure the ground blocks were good and needing a good ground to the R/R, I thought it might be good to mention. Aircraft and modern autos generally limit the ground connections to frame to one or two major points to reduce the potential electronics interference caused by "ground loops". Probably a minor issue for us, and it is certainly better to have a good ground to the R/R, even if that means adding a new one is needed. But it shouldn't be, since it worked as designed for a lot of years. That is why I stressed the need to ohm out the circuits and check the main grounding points - if there is a problem, it will affect the whole bike.

Goose

[Mordalo]

Thanks again for all the advice! As usual the community of friendly people on this site has been a tremendous help. Based on everyone's input it became apparent that the ground fault was (as a few people pointed out) at the point where the burn marks occured. That makes total sense. Since the burn markes occured at the R/R itself, that's where I started. I pulled the pin out of what was left of the connector.

 

By the way, if anyone knows where I can get a new connector without having to buy a whole wiring harness I'd love to know!

 

I got all the damaged plastic out of both the male and female sides. I used a file to get both ends of the connection shiny again. I used some electrical contact cleaner to finish the job, then I used pliers to tweak the female end to make sure it would get a good grip. I then fed the wire through the connector, which was easy to do since the connector had started to disintegrate from the heat, and connected it to the R/R. Then I slid the rest of the connector in to place. I slid the rubber grommet back over the black cable to fill the hole in the connector, and finished it off with high-heat silicone sealent to make sure no water gets in there. I re-wrapped the wiring using insulating rubber wire-wrap and good ol' electrictal tape and put the bike back together . Everything seems to be working now. I'm getting 13.8 to 14V when I run the bike at 4000RPM.

 

I'm not real happy with the current state of the connector and I'd love to replace it at some point. For now, I'll keep pulling the R/R coupler and re-doing what I just described every weekend (this bike is my only source of transportation so I ride it daily) until I'm confident that there is no further sign of a continued ground fault.

 

Thanks again for all your help!!

[GeorgeS]

Well from your description of your work I think you have it . I would just Watch the DC Voltage, at the Battery terminal couple times a month, to make sure the voltage stays 13.8 to 14.1. If so, your good.

 

Your not the first to have this problem on a 2nd Gen. Sombody mentioned that road wash, from front wheel hits this plug ( I'm not positive on this point though ) Sombody can confirm this ??

 

If you now have tight connections. And sealed out the water, it will most likley be ok.