The Hodaka Club Forum

Quickie question about Hodaka wiring: in my Wombat most of the connections between the main wiring harness and the engine, main switch, etc subharnesses is in the area behind the battery. Should those (mostly bullet) wire connections be stuffed into the selenium rectifier compartment behind the battery, or can they be arranged in that area above the battery box between the seat and the rear fender? I like neat and tidy wiring, but it needs to have access for inspection and maintenance.

--Bill

You should be able to run them where ever you want as long as they don't interfere with any other parts. Make sure they don't get pinched or rub on anything and you should be good to go

The selenium rectifier plate should not be touched by anything. Flexing the plate can destroy its functionality. In addition, if anything conductive touches the plate, the function of the rectifier could be short circuited. So be sure to stay clear of the selenium rectifier.

Ed

I'll keep that battery box area around the rectifier uncluttered, then. There are going to be wires passing through that area. On the areas where wires are crossing a metal piece, like the batt box and the headtube gussets I've gotten some 1/8" tubing and put a "chafe guard" so the insulation won't abrade. I'm a nutcase about tidy wiring.

The selenium rectifier is indeed fragile. Has anyone tried to substitute a silicon (off-the-shelf) diode, properly rated and heat-sinked, for it? Selenium is so 1940-ish. I wonder if there is a reason why Selenium is still used? The fwd voltage drop shouldn't be that different than the 0.6v Silicon rectifier, and I can't think if any advantages.

--Bill

I'd guess that selenium rectifiers were pretty inexpensive in the '60's and '70's . . . and they are still being used because . . . the bike has been in a barn for the last forty/fifty years???

Ed

Just read up on selenium _vs_ silicon rectifiers. For audio or vacuum tube circuits, there have to be some mode because the silicon has less of a voltage drop and switches faster, But for our automotive application, it shouldn't matter. If/When the selenium rect bites it, I'll convert over. Selenium and cadmium are bad metals to use in manufacture, anyway.

--Bill




PS-- messages crossed in the mail. That is what I thought, but (IIRC) the selenium is still offered as the replacement part, so go figure.

--b

I found this while I was searching for headlights. This will replace the rectifier and separately, also regulate the AC circuit. I understand that it will charge the battery more efficiently. It appears small enough that it could be mounted in place of the older rectifier.

http://www.regulatorrectifier.com/catal ... -Rectifier

$0.02

Roger

That is a good lead, Roger. "Modern" bikes that use a permanent-magnet alternator (such as Ducati) use this sort of regulator + rectifier. Had I not just plunked down to SH for a Wombat regulator, I'd try this. It looks like a good one-package solution.

--Bill