I Think I Fried my Pamco

[Port]

1981 XS650 SH with a Pamco ignition with Eadvance. 2009 tag on the board so I'm pretty sure it's a legit Pamco.

I'm trying to diagnose a no spark situation I got myself into. I was troubleshooting a charging system issue, jumped the Reg/Rec, and let it run a few seconds too long. I saw ~16.5V across the battery then the bike quit. It blew the Head Light fuse, and when I replaced the fuse the Reserve Light Box smoked to death. Cut out the box out and jumped (Blue/Black - Blue/Yellow) as recommended by a few other posts. It should be noted here that I have also removed the safety relay as it died a while back but was running fine until this incident.

I now have no spark and haven't fixed my charging system...

^What he means is if you have 12V on the red, that should go through the coil and appear on the green at all times except when the ignition is trying to fire the coil.

At the coil --
check for 12V from the red to ground.
If good, check for 12V from green to ground.
If 12V not on the green, remove green connector at coil and check coil there again.
If still not 12V there then bad coil
If you did get 12V on the green terminal only with the green wire removed from it, it means bad ignition or bad installation.
-- check ohms from red to where green was connected to confirm.

I tested the coil and it tested good across the primary and secondary. 30 Ω from cap to cap which seems a little on the high side but I think that is acceptable...? Before i tested the coil, it was making a hissing sound when I toggled the ignition on. I left it for a few hours and no more noise from the coil.

10.9V on the red at the coil
10.9V on the green at the coil
Constant 3v on the green on the Pamco sensor. I pulled the plugs and grounded them with wire so I could slowly turn over the engine to check. It doesn't seem like the Pamco is sending a fire signal.
Note: with a battery voltage of 12.2V ignition off, 12.0V ignition on, 10.9V at the Pamco, and up to the coil.

The green wire on the sensor plate is connected to the MCU input port which has an internal pull up resistor to 3 Volts. You cannot reliably see this with some meters. You have to use an oscilloscope with a very high input impedance.If you were getting a reading between near zero and near battery Voltage on the green wire to the coil when rotating the rotor, then the system is working properly.

I'm reading constant 3V but with a cheap DMM so not entirely confident that I'm not missing the fire signal.

It seems to me that I fried my Pamco. !!---If that is correct----!! then I suspect I might be able to replace this one component and be good to go.

- Has anyone ever seen such a failure?
- Has anyone ever done such a fix?
- Is this a Hall Effect Sensor? pretty sure it is and i guess there is a part number on the back side.
- Does anyone know the part number or a compatible alternative?

If we can solve this then I can get back to solving my charging system issue. At 3000 RPM i was only getting 13.5V across the battery. I jumped the Reg/Rec and got 16.5V so it looks like the stator is good. Tested the 6 diodes and they were all ~4.5 Ω so Reg/Rec looks good. So bad grounding? Original solid style Reg/Rec mounted in the stock location.

 

[azman857]

Do you still have the TCI pick up? Investigate the replacement of the PAMCO with a Gonzo Box. My blue box on the PAMCO went bonkers and replaced the whole PAMCO W/ Electronic Advance set up with the GN 250 iggy box AKA Gonzo box and all is good again. Easy peasy to do. Just saying...

 

[Port]

Yeah, i plan on it even if i get this pamco back up and running. I just dont want the bike to sit for a month waiting on it to get here from China. I could get one sooner for a price but i was waiting on the brain trust to get a bit furth in the testing before adopting.

One question i have in doing that.... I installed this Pamco a few years ago so I can quite remember where the [red/white & orange] plug went. Did the OEM coil have a pigtail that hooked up to that plug with one of those wires going to each of the primary side terminals on the coil?

 

[azman857]

sounds about right.

 

[650Skull]

That info is in here......tips and repairs in post #6
http://www.xs650.com/threads/boyer-and-pamco-ignition.46859/

 

[gggGary]

since it's got the separate e-advance box with the plugs OUT but grounded. Wire it without the advance box. See if it sparks then. But yeah high voltage smoking a pamco happens.