Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Rectifier issue?

During a long trip I noticed my voltage was dropping steadily, eventually read “Low” and later the gauge went out altogether. I made it home somehow. When I had a look around I noticed the rectifier ground had snapped clean off the terminal. The ring terminal was still attached to the frame but the wire was dangling. I’m guessing road debris or perhaps bouncing caused it to pull off. The rectifier is mounted to the engine, not the chassis.

I tried reconnecting with a new terminal but had no success - the voltage doesn’t go up past 12.0 while driving. Forward motion doesn’t make it go up at all.

I’ve ordered a new rectifier assuming being disconnected from the ground while driving home for over an hour with a steadily dropping voltage has caused it to fail. Does this sound like a fair assumption? I’m not familiar with this part and how being disconnected from the ground might impact it.

Cheers

The loss of the earth connection may well have led to the (inevitable) failure but the MMC supplied unit is notorious for failing anyway due to poor quality insulation rubbing and flaking leading to short circuits and vibration killing the internals.
I think most people replace the original with a Harley unit or Harley clone from Ebay. Much cheaper and last far longer than the original.

Interesting post and good support RedThree...

Hi GPC1203

Planenut maintins an excelellnet alternative parts list which is a great source of better/cheaper repacements and upgrades.

It sounds as if you've already ordered a MMC regulator but this might be useful in the future.

https://www.dropbox.com/s/w6rc8a1udgx4l2v/Updated%20List%20220319%20with%20contents.pdf?dl=0

Been There. Done That. I have talked with many bikers and they can pretty much sum up what the Cycle Electric unit is: Very Delicate or a POS.

The Harley unit is practically bulletproof.

So if one were to get the Harley unit would you mount it in the same location? Or where/else would you mount it?

People mount the HD unit in the same location as the factory unit, excluding any rubber bobbins you have, the hole fixings are the same centres and the plug to the loom is the same, you just need to change the ring terminal for a larger one to connect to the B post

Ditto. I removed the extra plate with the attached bobbins and just stuck the thing directly on the plate without cushioning of any kind. Going on 47,000 miles that way!

Thanks for the mounting tips guys!

Thanks all for the info thus far. I received the new part and started working on the replacement...

I wonder if mounting the CE-601 I have to the plate without bobbins will cause certain failure? The only reason I'm considering this is because the unit I received has a shorter plug that barely reaches it's connection point without snipping the plastic tie to the chassis. If I snip it, the cable touches the oil filter which makes me worried the nearby heat will cause it to melt. I'm thinking removing the bobbins will give me the slack I need.

I managed to get the old 601 off (with much difficulty! The nuts are so damn close to the rectifier body...), splice a new larger ring terminal for the junction stud, and connected the new ground. She fired up nicely and voltage is now reading normal, so it appears the old rectifier was the issue and the new one is charging the battery. Now just need to figure out my mounting to avoid the plug cable from being pulled tight or touching the oil filter.

I'm not much of a mechanic so I was pleased to get as far as I did!

Anyone else experience this cable length issue? Any insight would be much appreciated.