Electric nightmare

[bikehandle]

Hi all!
This spring I posted about a problem I am haveing with my vision. I replaced the stator and the Reg and the problem I have is it runs about 13.2-13.4 at idle and about the same at any other speed also. I was so flusterated I took it to the shop. The stator and the rest of the componets check ok? All the connectors on the bike were cleaned and greased, still 13.2. at any speed. What they did find out was if the headlight was unpluged from the system is it would run 13.4 at idle and 14.5 at 7 grand. Plug the light back in it would flatline back to 13.2-13.4 at any speed?? This has us totaly stumped! I need some info badly or I swear to god this bike is going to commit suicide with my help!!!!
Bikehandle

[Junior]

bikehandle-Just a hunch, but please tell me where are you (they) taking the voltage reading when you check the bike, and what type meter are you checking it with-Thanks

[Lucky]

First, while 13.2-13.4 is not "text book" it should keep your battery charged just fine. you really have little cause for alarm...

while the headlight is a clue, disconnecting it shows that the system has the capability to produce "textbook" figures.

with the electrical load reduced, the charging system shows perfectly normal figures. this suggests one of two things: (Keep in mind, one symptom with multiple causes is a normal ocurrence in any vehicle)

1) the headlight is drawing such a high load (or just enough load) that the charging system is unable to 'keep up'.   normaly a R/R will increase the output as load increases. the Electrex tests do NOT address this as far as the R/R is concerned. it does thest the stator AC output.

To test this theroy, apply additional load to the system while you have a meter attached.  this can be done with a simple automotive load tester (pile resistor). use caution here, you should apply load for no more than 10-15 seconds at a time.

If the voltages drop as the load is applied (keep the headlight attached) then the R/R is at fault (assuming the stator passed the AC test) If the voltages do not drop, but stay at the 13.2-13.4 range, then the R/R is at fault only as far as it is not operating at it's designed specs, but is functioning 'normally'.  If the voltages rise, then the R/R passes, & the problem lies elsewhere:

2) the bike overall has high resistance in the electrical circuit.  we are talking about bad grounds (neg from battery & harness ground on the left coil mounting bolt) and too much overall resistance in the harness connectors. (clean & tighten all harness connectors).  The R/R black wire to the bikes harness is especially suspect. Have you soldered all the connectors on the R/R as we advise?

A note about electrical components: Quality controll gernerally sucks.  Working for Ford 15 years, & turning wrenches for over 25 has tought me that if an electrical component fails a test & is replaced, & still fails the test, suspect the new component.

hope this helps...

--Lucky

[Junior]

Bikehandle-Glad Lucky answered your post. His advice has been a great help on my V. I had the same problem you did on voltage and it turned out to be inline resistance regarding harness and connectors. If your voltage jumps up when headlight is disconnected, your stator and R/R is working. I changed many things including fuse box. Could only get 14 volts + at low rpm idle. V consistently run between 13.5 and 13.9 while riding, always ran good. I could never get text book reading. I sold my V yesterday. The offer was just too good to not sell. It was cherry though, and my tool box will think I have deserted it, wife probably wonder why I am hanging around so much now. LOL

[Mutt]

If upluging the headlight makes that much of a difference, could it be the lamp itself? Possibly too high a rated lamp/wattage? Do you know if it's the stock lamp or an after market? Simple I know but it's the only thing electrical about your head lamp other than the bulb socket itself.

Mutt

[bikehandle]

Thanks!!
I had noticed the light was yellow and would not brighten with revs. I checked the voltage at the battery and it was showing low numbers and would not increase with revs. I sent for a ricks stator and electrics RR. Pulled the stator and found it looked like new. put in the ricks stator anyway and the same with the RR. Test at the battery and the voltage was the same as before with the old parts. If I started the bike and rode a hundred miles no problem other than the light would be dim as hell. the problem was if I did a lot of starting and stoping the battery would run weak(new battery) The connectors are in very good shape on this bike + the shop checked for voltage drop at all the connectors(not the problem) every connector on this bike has been checked including the ones in the headlight shell and the fuses. 2 RRs and both do the same thing. what I am not getting is the fact its not sencing the load and increaseing the voltage from the stator? as a matter of fact with the headlight hooked up the voltage will dip some with revs???from idle. I have never had any bike put me against the wall like this!
Bikehandle

[Lucky]

ok, then that narrows it down to two possabilities, either there is a problem with the bulb itself (since that seems to be the one obvious symptom) or there is a problem with the brown sensing wire for the R/R.? now the interesting part: the brown sensing wire splices to two points: the main switch & guess where else? the headlight circuit by the fuse box..

check the wiring in those two area's, & like Junior said, check the fuse box carefully. sometimes the fuses look good & are weak or bad, swap them out to eliminate them as a possability. also, if it's a stock fusebox, check the contacts carefully, they crack & break off with age. if the fuse box has been replaced, check the solder joints carefully too, wiggle them around & watch the voltage.? corrosion in the main switch could be a big problem as well.

time for you to play detective...

--Lucky

[Rick G]

All old Yamahas have crappy fuse boxes , you should replace it as cheap insurance. Its one of the first things I do  on a bike with electrical problems.  Napa has a nice selection in there catalog , but others may be less expensive..

[bikehandle]

I should have said the fuse box has been replaced . We tryed the unit with a diffrent bulb too. Will check what you said Lucky. Thanks!