rectifier/ regulator

ok. my 78' 650 ran well b-4 i took it apart and built an 810. I have it all back together and looking good now. she starts and runs with a jump, but after i disconnect the jumper cables she dies in about a minute.

it isnt putting out more than 12.5volts at idle through 4krpm. the altornator is putting out the 75 AC volts that it should (2 yellow wires).

i have tried to test the rectifier/regulator OHMs, but am not getting any reading between the black wire ant the 2 yellow ones, not even a too low or too high reading.

does this mean i need a new rectifier/regulator???

what could cause her to blow?? dont say age, because it WAS working when i tore it down!!

thanks guys

hmmmmmm? anyone?

If the reg module is wired in correctly, and your alternator is putting out juice, it seems like the reg/rect module must be bad if it is not charging. Inside they have SCR silicon devices and an integrated circuit to control them. As to why semis blow when they do? Not sure anybody knows that answer.:laugh:

Lacking any response from our more erudite electrical members I'd suggest that your battery is dead. It may not have been dead when you started your project but it's dead now. Additionally your rectifier/ regulator is toast.

Your battery may have been charged before you took it apart but your system's not up to maintaining it now.

Any chance?

KZCSI

Dead battery doesn't really fit the symptoms posted in the OP:

it isnt putting out more than 12.5volts at idle through 4krpm

Even if the battery has a weak or shorted cell, a working alternator/regulator will be able to make the battery voltage rise above 12.6V. The battery may indeed be worse for wear from being run off without charging, but the source cause of the problem is probably not the battery.

You can get a good gauge of the battery's health by trickle charging it for a couple of days then testing it by measuring the terminal voltage while you crank the starter over. If the battery is staying above about 9.5V during starter crank, it's probably OK.

You may also want to check all the high current ground connections.

Well yeah, the battery is dead, i have a new one on the way. but thats not the real problem (like bounty said). the alternator isnt charging the battery, it IS putting out a charge, the charge isnt making it to the battery though.

I have tried to test the rectifier/regulator with my multimeter, but i dont get any readings........

what am i doing wrong? how do i test this thing??

If i have a shit battery in there that holds some juce, just not enough to start the bike, shouldnt i be able to run the engine through the battery on its own power?>????

pburnhamb wrote:

If i have a shit battery in there that holds some juce, just not enough to start the bike, shouldnt i be able to run the engine through the battery on its own power?>????

If the reguaator/rectifier is bad the current to the battery will not be enough, or way to much. When you work the components like that to make up for a dead battery something will usually go out. I am waiting for a voltage regulator in the mail as we speak. Good Luck

I had this problem before, and consulted Jeff @ Z1ENTERPRISES.

He told me it was basically futile trying to use a multimeter to diagnose those things. Its more like a process of elimination. You have to check everything else with your meter first, then if all else seems fine...

Anything under 10volts I think, is just not enough juice for the coils to spark efficiently. Your plugs will start to foul bad. Hesitation... stalling..etc., and batt. will drain fast!

Good luck.

TeK9iNe wrote:

I had this problem before, and consulted Jeff @ Z1ENTERPRISES.

He told me it was basically futile trying to use a multimeter to diagnose those things.

+1 You test a suspect rect/reg by installing it in a working system and see if it regulates. Ohming it out is pretty useless.

K, thanks for rubbing it in!! this is my only bike. no way to test it in a running system...

ordered a new rectifier/regulator. from the Oregon cycle parts guy. comes with a lifetime waranty, just return it , no questions asked. sounds good to me!!

hope she is the problem though.

Did you get the new regulator and battery yet?

I am having similar issues on my 650 and want to see how you do.

Bump!