Wednesday, July 01, 2015

Honda 1979 CX500 Headlight, Sealed Beam to H4 LED conversion

My daughter moved a ways away so I blew money I had put away for tuition on a motorcycle so I could drive out there more often this summer.  The bike is a Honda 1979 CX500 and it runs okay.  There is a harmonic shimmy occasionally, so I probably should replace the swing arm bearings.  The bike has a shaft drive and I haven't done that on a bike with a shaft drive, so, haven't done that yet.  It rides okay.

Somehow, in 36 years no one managed to do a sealed beam to H4 headlamp conversion and the low beam was burnt.  This is a real simple, fairly cheap thing.

First, I needed the conversion light.  I bought a IPCW CWC-7006 7" Plain Round Conversion Headlight from Amazon.  Under $15 bucks.  Search around, you might find one cheaper.

Second, I needed an H4 bulb.  That I ordered from eBay, 22watt, from China, about $6.   22W White H4/5730 CREE LED Fog Light Bulb 1000LM High Low Beam Headlight

Again, look around because I wasn't exactly trying to do this super cheap.  I was just trying to avoid the scam artists selling "conversion kits" on eBay for $60 bucks.  Maybe I should put together a few "conversion kits", add some instructions and sell them.  Nah, I am not interested in ripping people off.

There is a difference between the conversion headlight and the sealed beam, there are stand-offs and the stand-offs on the conversion are higher than on the sealed beam.  I thought about hack sawing them off, but, didn't need to, so I didn't.

There are eight screws to deal with, all phillips head.  You will need both a #1 and a #2.  I used a screw driver with switchable heads.  Remove the three screws holding on the headlight assembly.

Pull the connector from the back of the sealed beam.  This connector works fine for the H4 bulb, just don't get a high wattage bulb.  If you do, you could burn the connector and the alternator.  You could try wiring in a ceramic socket, but, I wouldn't bother.  The alternator specs won't handle the load.  I suggest LED.

The sealed beam is in a retaining ring inside an adjustment ring.  Remove the two pivoting screws, don't lose the stamped steel "nuts".  Loosen the headlight adjuster screw on the outside of the retaining ring.  You need a #1 phillips here.  Don't lose the spring or the little square nut.

I like using a paper bowl or a small can or something to put my bits and pieces in.  Lay them carefully in the grass, whatever.

There are two screws holding the sealed beam into the retaining ring.  #1 phillips.

Now, if the locater tabs are too big, cut off with a hack saw.  These help position the headlight in the correct orientation, so leave some stubs and file them all down so they are the same height.  I wouldn't do this unless you have to, I suggest avoiding cutting stuff up.

Swap the sealed beam for the conversion light. Rotate the conversion light around so the locater tabs fit in the correct places in the mounting ring.  Slip the retaining ring on and replace the two screws.

Put the light assembly in the adjuster, put in the pivot screws first.  The top pivot screw mount is also a tab for the head light mounting screw.  Make sure the pivot screw goes in the "middle" hole.  Those stamped steel nuts are a pain, but, play with them and they work.  You could try replacing them with real hex nuts, but, I wouldn't.

Push the assembly down against the adjuster spring, spin the nut down a ways and eyeball how even the adjustment looks.  You can use a screw driver to fine tune it.

Put the H4 bulb into the light.  There are some wires that snap loose, you might need a screw driver to push them down, then in, towards the opening.  Remove the shipping cap.  Put the bulb in, use a screw driver if you have to.  Just be careful.  Attach the socket.

Test the light, everything working?  Proceed.  Not, sit down and cry for a while, then dust yourself out and figure out what is wrong.

This is the hard part.  I think the conversion light is slightly deeper than the original so, create a "nest" in the wires for the light plug, and shove the thing together.

Put the two lower screws in first.  It might take some real force to push this together, if it takes too much, work on the next some more.  Once the lower screws are both in about half way, put in the top screw.  Now tighten everything up, tight.

Test the light a second time, everything should work peachy keen.


Ryan Salzmann said...

I have a 1980 CX500 that I just purchased. Do you think that a 30W bulb would be too much? I prefer to avoid ebay if possible and I found a bulb on Amazon that is 30W.

John D. Ayer said...

Hi Ryan: Sorry it took me so long to get back. The CX500 has a small alternator so the wattage of a replacement bulb should not exceed the wattage of the original. I believe the original was a 30watt bulb, so, it should be okay. I would double check the specs though. As these bikes get older reducing the load on the alternator is a good idea.