Powerdynamo regulator/rectifier

Blue400 · March 28, 2020, 02:55:38 PM

Hi! On my 77 RD400 i have a powerdynamo ignition installed, it has worked great for close to probably 8 years now roughly, have any of you with this ignition setup have an issue with the regulator/rectifier causing a short and blowing out the 20 amp main fuse? And is there a way to test it with a meter to determine its bad? Thanks in advance.

Dvsrd · March 28, 2020, 09:08:43 PM

Quote from: Blue400 on March 28, 2020, 02:55:38 PM
Hi! On my 77 RD400 i have a powerdynamo ignition installed, it has worked great for close to probably 8 years now roughly, have any of you with this ignition setup have an issue with the regulator/rectifier causing a short and blowing out the 20 amp main fuse? And is there a way to test it with a meter to determine its bad? Thanks in advance.

I assume your 20 A fuse is installed between the battery and the bikes harness. It seems very unlikely to me that a faulty Powerdynamo regulator can blow that fuse. If your battery is healthy, the charging voltage, measured at battery poles should be around 14 VDC @3-4000 rpm.
I believe you have a short somewhere in the wiring loom/ lights/switches.

1976RD400C · March 29, 2020, 08:14:47 AM

The rec/reg red wire does go to the main 20 amp fuse then to the battery. If the rec/reg is shorted it will blow the fuse even if the key is off. Try unplugging the rec/reg and see if it stops blowing the fuse.

m in sc · March 29, 2020, 10:18:06 AM

actually...

if your battery was super low and you fired it off, the regulator will allow a lot of voltage and spike. I did this, this caused me to kill a zeel box, a regulator/rectifier, and an spa tach instantly.

Yes, it was an expensive fix. the new ones have a capacitor to allow them to 'take the hit'. My powerdynamo was from 2007, this happened a bit over 2 yrs ago. So, its possible, yes.

Blue400 · March 29, 2020, 10:33:06 AM

The red wire from the regulator goes through the fuse to the battery, like it should. First thing i tried was unplugging the key switch with no luck. Then i tried unplugging the black wires going to the stator, still blew the fuse, if i unplug the red wire to the regulator, it does not blow the fuse. So that tells me the main harness is fine. What do you guys think? Oh and all this is happening with the key off, i was going to fire up the bike one day and noticed out of the blue i had no power when turning the key on, and noticed that fuse was blown.

Striker1423 · March 29, 2020, 10:46:51 AM

Quote from: Blue400 on March 29, 2020, 10:33:06 AM
The red wire from the regulator goes through the fuse to the battery, like it should. First thing i tried was unplugging the key switch with no luck. Then i tried unplugging the black wires going to the stator, still blew the fuse, if i unplug the red wire to the regulator, it does not blow the fuse. So that tells me the main harness is fine. What do you guys think? Oh and all this is happening with the key off, i was going to fire up the bike one day and noticed out of the blue i had no power when turning the key on, and noticed that fuse was blown.

That tells me the harness isn't fine and the red wire is finding ground somewhere. Most likely a portion of uncovered wire rubbed through the shielding and is grounding out.

1976RD400C · March 29, 2020, 11:05:27 AM

Quote from: Blue400 on March 29, 2020, 10:33:06 AM
The red wire from the regulator goes through the fuse to the battery, like it should. First thing i tried was unplugging the key switch with no luck. Then i tried unplugging the black wires going to the stator, still blew the fuse, if i unplug the red wire to the regulator, it does not blow the fuse. So that tells me the main harness is fine. What do you guys think? Oh and all this is happening with the key off, i was going to fire up the bike one day and noticed out of the blue i had no power when turning the key on, and noticed that fuse was blown.

The regulator/rectifier is blown. It is shorted. You proved it with those tests. Unplug it and install a new fuse and the bike should start. That will prove everything is ok with the cdi.

Blue400 · March 29, 2020, 12:49:12 PM

Quote from: Striker1423 on March 29, 2020, 10:46:51 AM
Quote from: Blue400 on March 29, 2020, 10:33:06 AM
The red wire from the regulator goes through the fuse to the battery, like it should. First thing i tried was unplugging the key switch with no luck. Then i tried unplugging the black wires going to the stator, still blew the fuse, if i unplug the red wire to the regulator, it does not blow the fuse. So that tells me the main harness is fine. What do you guys think? Oh and all this is happening with the key off, i was going to fire up the bike one day and noticed out of the blue i had no power when turning the key on, and noticed that fuse was blown.

That tells me the harness isn't fine and the red wire is finding ground somewhere. Most likely a portion of uncovered wire rubbed through the shielding and is grounding out.

When i unplugged the red wire going to the regulator/rectifier, then the fuse did not blow.

Blue400 · March 29, 2020, 12:52:04 PM

Quote from: 1976RD400C on March 29, 2020, 11:05:27 AM
Quote from: Blue400 on March 29, 2020, 10:33:06 AM
The red wire from the regulator goes through the fuse to the battery, like it should. First thing i tried was unplugging the key switch with no luck. Then i tried unplugging the black wires going to the stator, still blew the fuse, if i unplug the red wire to the regulator, it does not blow the fuse. So that tells me the main harness is fine. What do you guys think? Oh and all this is happening with the key off, i was going to fire up the bike one day and noticed out of the blue i had no power when turning the key on, and noticed that fuse was blown.

The regulator/rectifier is blown. It is shorted. You proved it with those tests. Unplug it and install a new fuse and the bike should start. That will prove everything is ok with the cdi.

So the bike should start with the regulator/rectifier disconnected?

m in sc · March 29, 2020, 02:05:54 PM

as long as it doesn't rely on a relay to kill the bike. you may have to bypass that if its there, but then you have to kill it another way.

id bet the regulator fried due to over charging like mine did. how old is the battery? mine dead shorted as well.

rodneya · March 29, 2020, 02:40:33 PM

Will the newer Vape regulator work on the older systems?
Did anything on powerdynamo change other than going from static timing to CDI?

1976RD400C · March 29, 2020, 02:57:51 PM

With the regulator unplugged (because it is shorted), a good fuse in place, key switch plugged in, and a charged battery, the shut down relay will turn on ok and should start up.

Blue400 · March 29, 2020, 03:00:16 PM

Quote from: m in sc on March 29, 2020, 02:05:54 PM
as long as it doesn't rely on a relay to kill the bike. you may have to bypass that if its there, but then you have to kill it another way.

id bet the regulator fried due to over charging like mine did. how old is the battery? mine dead shorted as well.

The battery im pretty sure is around 10 years old, maybe i should replace that as well. I had not ran the bike in probably a month due to winter setting in up here in MN, went to start it and there was no power to the key, fuse was popped, so it went bad while sitting.

Blue400 · March 29, 2020, 03:14:23 PM

I hooked everything back up except the red wire for the regulator, no spark.

m in sc · March 30, 2020, 07:42:48 AM

yeah, you need to unplug the blue wire from the coil to the relay if its there.

yup. my battery was 8 yrs old. then pow.

and yes, the new regulator works with the older units.

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Powerdynamo regulator/rectifier