Electrical Mystery

[rocket_man]

I have some leads towards solving my electrical mystery (no pun intended), but am unable to solve the case.

I picked up a '87 Paso last year, which happened to belong to "mike" just prior to the owners I bought it from. It ran great at first; just from time to time it would stall while idling. Then one day the connectors attached to the yellow wires running from the regulator to the alternator overheated and melted, while blowing a fuse. Since then I have been unable to ride the bike due to low voltage across the battery at idle.

Here are my leads - Although I replaced the connectors on the yellow wires they still get very warm. When the ignition is turned on the battery voltage will immediately drop at least 0.4V across the terminals. With the ignition off I get 9mA of current flowing from the battery, although if I disconnect the six pin connector on the instrument panel directly behind the tachometer it drops to 0mA. So with the bike at idle the voltage in the battery continuously drops below 12V until the bike stops, but at 3,000rpm it reads 14V. If I apply a touch of choke to up the rpm to ~ 17,000 it holds steady around 12.7V. Also, I just noticed that the two yellow wires from the alternator are combined into one yellow wire at the regulator, which looks like it has been replaced by a newer version. Don't know if that is an issue. Anybody have any guesses as to the problem?

Thanks in advance. I am really anxious to get riding!

Michael

[paso750]

Michael,

the 9mA are probably from the dashboard clock.
Try to check all ground connections and clean them. There should be one at the regulator, too.
The wiring of the regulator is ok. I also have a newer type of regulator and it`s the same thing.,

Hope your bike doesn`t really revv up to 17.000rpm

Gerhard

[rocket_man]

I think you are right about the clock, although isn't more than 0.1mA supposed to indicate a short of some kind (Haynes)? Oh, and my bike was "idling" at 1,700rpm, not 17,000 although I sometimes wish I could get it that high at speed I will clean up the ground connectors and take a look at that clock. Hope that does the trick.

Thanks - Michael

[qldman36]

I think you are right about the clock, although isn't more than 0.1mA supposed to indicate a short of some kind (Haynes)? Oh, and my bike was "idling" at 1,700rpm, not 17,000 although I sometimes wish I could get it that high at speed I will clean up the ground connectors and take a look at that clock. Hope that does the trick.

Thanks - Michael

As far as the clock goes, can be a REAL power robber. My clock was noisy and in no way would keep time. With new fully charged battery, needed to be started and battery built up at no more than two week intervals. Disconnecting battery ground worked- -just don't forget. Battery tender? Great if you have power where you keep bike,i don't.
Tried to find out how to disable clock, had no luck, did it quick and dirty.
Bike sat after Daytona bike week for 2 1/2 months, hit the starter- - fired right up! {battery about 1 1/2 years old]

[rocket_man]

I may do the same to my clock. Anyway, I cleaned all of the grounds and so far no luck. I found a connector next to the steering column that looked like it had been fried and later fixed. When I disconnected it the battery no longer dropped in voltage with the ignition turned on; the bike also would no longer start. It looks like the head lamp, dashboard, and ignition is powered by the red wire that runs through this connector. Is this sort of voltage drop ( ~0.4V ) abnormal, or is something else the problem, e.g. regulator?

[paso750]

here`s how to test the ragulator. Basically I had just made a fast drawing of what is described in the Haynes manual:

http://www.geocities.com/750paso/paso/regulatortest.pdf

this may help also:

http://www.geocities.com/750paso/paso/faultfinding.pdf

[rocket_man]

paso750

Thanks for the info, belatedly. I've since discovered the problem: a corroded, multi-lead ground, located underneath the steering column head attached to the frame. Since then, with practically all of the electrical leads cleaned and preserved with electrical contact goop, my bike has been charging just fine. No modifications to the electrical was necessary. Of course, there is just barely enough juice in the system to operate at 1,100 RPM+ sustained driving.

But, it roars like a lion! The next door neighbors kitty lost one of its lives just hearing it.

[jcslocum]

Wow, almost 3 years to the date !!

Glad to hear all is well and that you found the problem.

[persempre907]

Better late than never .
Ciao

[JWilliam]

I just noticed that the two yellow wires from the alternator are combined into one yellow wire at the regulator, which looks like it has been replaced by a newer version. Don't know if that is an issue.
Michael

I would check this out too even though its riding OK now. A wiring diagram should tell you about this. My 906 has three wires from the alternator and they do not join up but plug separately into the rectifier.

[paso750]

the regulator, which looks like it has been replaced by a newer version

if its i.e. an Electrex regulator it`s correct
http://www.electrosport.com/technical-r ... ctions.pdf

G.

[rocket_man]

JWilliam & Paso750

Thanks for the tip. It is an Electrix, so I am cool.

To help out, I put the battery on a charger when I'm not riding. After a recent five hour ride, I checked the battery voltage and it read 12.7V. Without the charger, it would eventually equilibriate around something closer to 12.0V...probably because of that damn clock!

I don't stress it though. It handles my day rides just fine!