Electrical problem that stumps me

[bikenut]

OK working on a bike that was not charging at all. Replaced stator and the rec both tested bad. Now the bike which is a 2006 Venture is charging 13.3 and just off idle it will hit 13.5 at 1500 rpm, rev it up it goes down to 13.1 at 3000 rpm or below to 12.9 at 4000 rpm. this one got me pulling my hair out.

Forgot to say also the guy said his bike keeps blowing the Rec .

Any ideas would greatly help

Thanks Guys

[Larry1963]

[Guest Jamsie]

if you just replaced RR and stator and do not suspect either to be faulty items, check loose/corroded connections in the charging circuit and also battery ground. get the battery load tested .

[Flyinfool]

First it is entirely possible to have a new bad part.

 

IN the testing did you fully charge the battery and have it load tested? If not start there.

 

BY Rec I am Assuming that you mean the Regulator/Rectifier (RR)?

 

Since the voltage starts a bit low at idle and drops as RPM goes up. it could be something drawing a lot of excess current, especially since he said he keeps blowing RRs. the only RPM dependent thing that draws power is the ignition system. The faster the RPM the more current it pulls.

 

Do you have a clamp on DC amp meter to easily check current draws on things while it is running?

 

Check all of the fuses to be sure that the correct fuse in in every slot and that someone did not put in a bigger fuse to stop a fuse blowing issue. Don't forget to check any aftermarket lights horns or other stuff to be sure it is properly fused and a realistic fuse rating for the job.

[bikenut]

Battery is also new and I had them test it at the store and full charge on it before buying.

I have never seen this on any other bike. more rpm should give you more output up to 14.4.

I just replaced the new rec with my spare rec just to see and it does the same thing with my Yamaha new rec that was for my bike and does the same thing.

Will dig into the ground cables and positive side also to clean the connections and see if that takes care of it.

Thanks for some ideas

[MiCarl]

Unfortunately there are a number of things that can cause these symptoms.

 

Given the new parts the likely suspect is bad wiring connections. You need to check the voltage at the regulator/rectifier. If you're getting 14+ there then there is too much resistance somewhere. It can be a bit at more than one connection adding up to a lot. I've had motorcycles where I needed to fix a half dozen connections before they charged right.

 

I just did one last week where the resistance was on the ground side. I solved that by just splicing an additional frame ground into the (-) wire on the regulator/rectifier.

[djh3]

I have heard the connectors on the back part of the motor for the stator are pretty bad about burning and corroding. But you just replaced the stator if I read this right. If you have a jumper cable connect to the ground @ battery and to a good engine ground. This should help if its a problem like MiCarl had. I had issues with the main fuse connector being all corroded.

[Yammer Dan]

Above the Stator there are three wires togather that usually end up with connection problems. Can't remember much about them. Could pick them out if I were at bike. Somebody???

[Black wing]

as silly as it may seem possibly the fly wheel is bad. if the magnets overheated, cracked or just plain weak from the factory they might not be strong enough to induce the magnetic field required. but before popping that off i would unhook every link in the harness and test each length and plugs for abnormal resistance.

[cowpuc]

Above the Stator there are three wires togather that usually end up with connection problems. Can't remember much about them. Could pick them out if I were at bike. Somebody???

 

I am not even exactly sure what bike we are talking about DanL so dont feel bad Thinking we might be talking 2nd Gen but - iff we are in fact talking about a MK1 or MK2 then maybe I can help.. That harness with a set of 3 white stator wires inside it should have a 3 spade terminal attached to the frame spar above the forward bevel gear on the left side of the scoot (left if you are sitting on the bike). Gotta remove the plastic side body panel to see it. Lots of us old timers have removed that terminal and hard wired our stator harness cause we got sick of that puppy causing issues.. I actually had a BRAND NEW high amp terminal fail me there once - melted internally - blades touched together and POOF, stator went on permanent vacation..

I got fooling around one day playing with my ohm meter.. I know factory testing on those leads is like 3 to 7 ohms tested across each other and then testing each to ground = ya want infinity.. I also discovered that (going from memory here and its been a while so dont declare triple probation on me if I am wrong) if I left the terminal plugged in and started the bike - with a good stator I would read 11 or 12 volts AC across those leads - seems like that peeked at like 14 volts on the revs.. A bad stator I did the same test with tested like 8 volts AC.. WHEN PLUGGED IN TO THE TERMINAL.. (ya gotta test under the terminal with the little poker on the end of the test leads)..

Not sure exactly what all that means cause I dont know squat about lectricity and I know there are easier ways to tell if your stator is gone (like look at your volt gauge on the dash - if its working backwards when ya rev the motor it's probably a good idea to check the connector we are talking about and maybe even stator time) but I that was fun typing that non the less:missingtooth:..

 

Thinking the 2nd Gens might be different with that infamous 3 blade terminal no longer in existence and the terminal now being down on the rectifier.. Stators being stators - seems like even of that is so, the testing should be about the same...

[Yammer Dan]

You are right Puc. Middle of night and trying to make sure puter is gonna work right. BIKENUT IGNORE WHAT I SAID!! But I would still check all connections.

[bikenut]

I will be looking at all connections and battery terminals and grounds. Way to hot here for the next few days 100 + in Wisconsin is not normal so after the heat I will dig into it again. All you suggestion are great ones.

By the way the connection from the stator is hard wired already when I changed the stator I soldered that connection and removed the plug which was burnt a little

[bikenut]

Ok today I will get the bike back on the lift.

Just wondering where all gounds are on the bike. I know the one by the horn. In the fairing but just wondering were the ground goes for the Reg/rec go to??? . Any other to check???

Thanks for the help

[MiCarl]

It's unlikely to be an actual ground per se.

 

You need to start by measuring charging voltage at the regulator/rectifier. If it's low you know you need to look into the regulator/rectifier, the stator and the connections between them.

 

If you get normal charging voltage at the regulator/rectifier then you know you have some resistance outside the charging system. Check the regulator/rectifier (+) to a good ground. If you still have charging voltage you got lucky - just add another (heavy) ground onto the regulator (-) and you can move on. If the problem is on the (+) leg you'll need to start checking every connector, fuse and switch between the regulator/rectifier and battery.

[gggGary]

Just wondering.... how many times has a bike ended up in pieces on the shop floor because the owner assumed the "new parts" were good?

[Flyinfool]

A lot more than once...............

 

Happens for cages too..............

[bikenut]

I did check all the parts I installed before installing them. Stator check good and very good output running,Reg/ref test per the service manual pasted. still have to check output of the rec/ref at it. So far found one ground that had some corrosion so I cleaned that up ,still looking for the rest. next will take fairing apart to check the grounds up there also.

[bikenut]

OK I got the thing fixed. 14.0 at idle and stays there all the way thru the rpm range. l found two grounds bad corrosion one on frame by steering head and the Battery neg end was all white so I cleaned both up and soldered the neg end on the battery cable. Then I stated to think about the ignition switch. So I took that out , was not hard someone else did it before and just used bolts not the break off one again . Took the switch apart and full of corrosion , The guy did not want to replace it so I cleaned it up very good put some Dielectric grease on all the pins and on the black board also. Put it back together and hooked everything up again ,started the bike and the meter went right up to 14.0 and 14.1 pops up here and there.

Just wanted to let everyone know we got it and Thanks for all the suggestion. That helped getting more minds thinking about this problem