THE SYMPTOM
One evening after dark, someone pulls along side you at a traffic light and says “Hey idiot, are you aware that you have absolutely NO brake lights or tail lights?”
THE DIAGNOSIS
You get home safely and pull the tail lamp lens to inspect your bulbs. You remove one bulb and look at the GOOD filaments and can't figure why it won't light. Cleaning the electrodes on the back of the bulb and pressing some additional spring tension into the socket contacts eventually get it to work. You try to remove the other bulb but it won't budge. Eventually, the globe shatters and sends shards of fine glass into your thumb and index finger leaving the connector base firmly planted inside the socket structure.
THE PROBLEM
Guzzi sourced a tail lamp which uses a plastic reflector globe with an INTEGRAL molding to hold the light bulb and the various copper connectors. The connector strips are made of very weak metal and DO NOT provide adequate spring force against the light bulb contact points. Poor electrical contact generally equals HEAT. The metal base of the light bulb gets hot and it is not very happy in the plastic socket housing. The small bayonet tits eventually melt themselves into the surrounding socket structure. As the bulb recedes in the socket, the connection gets worse and the heat gets worse until it all snowballs and eventually fails.
THE SOLUTION
The subsequently melted reflector is NOT a separately listed Guzzi part. So, in order to keep original appearance, your ONLY option is to bore out the center of the reflector housing and glue in a HIGH QUALITY replacement metal socket. Not so easy to do accurately.
SERVICE TO THE RESCUE!
I have two '98 EV's so I spent some time to permanently solve this problem. First, I made a clamping jig for my lathe which allows me to firmly hold the flimsy reflector housing in place and gradually bore out its center. This makes an accurate, snug-fit hole which also keeps the bulb filaments on the center axis and in the focal position of the semi-parabolic reflector.
I went to the local moto salvage yard and found plenty of VERY high quality taillight bulb holders. With a small amount of razor blade modification, they work beautifully in the Guzzi reflector. Add a few spade terminal connectors and it becomes an easy, quick installation with virtually no reason for future failure save for normal bulb filament vibration failure.
This is an original Guzzi reflector and next to it an identical reflector modified to receive the replacement socket.
This is what the repair process looks like after gluing the used socket into position and adding the spade terminal connectors.
Plug the wires as follows. I recommend that you use some pliers to gently close your original spade connectors for firmer connection.
My red to your Guzzi yellow, this is the low wattage running lamp.
My blue to your Guzzi red/blue, this is the high wattage STOP lamp.
My black/yellow ground to your Guzzi exposed black ground.
There is enough room behind the reflector to allow the connectors to be pushed back into place in the tail lamp housing. If you have crowding difficulty, you may wish to remove your license plate and the outer cover of the wire chamber to pull the wires back somewhat for easier fitment. It is usually possible to just remove the two Phillips screws from the wire chamber cover and then gently rotate the license plate to the side and expose the wiring.
HOW TO GET YOURS
First, contact me in advance to confirm that I have the necessary bits on hand and will be available to modify your reflectors as soon as they arrive.
Second, once advised, remove your reflectors and post them to me. I am usually able to do the conversion, allow the glue to dry, and post back out within 24 hours. You should have the replacements back to you within the week. If you want them faster, pay for faster postage. If you want to keep your bike running in the interim, just send me one reflector and drive with the other in operation. You'll have to do it twice and pay double postage, but you can keep running in the meantime. Up to you.
Third, when I receive your reflectors, I will modify them as quickly as possible, usually over night. I need the glue to dry before I can re-package for shipment.
Fourth, when you send your reflector package to me, you need to include some small amount of money to pay for the consumables. You get two quality bulb sockets that now cost $7 each. You get six, protected, male spade connectors crimped onto the wiring so they are a simple plug-and-play when they get back to your bike. Those connectors are a quarter each for total of $1.50. You get a little bit of JB-Weld, perhaps $1, which holds the replacement sockets into the original reflectors. I have to mail the same box back to you for perhaps $6. So, lets say $25 covers all the consumable parts and postage plus a little bit of the gasoline for me to schlep off to the electronics store, to the moto salvage yard, and to the post office. If your reflectors get lost in the mail on the way to me its not my problem. If the replacements get lost coming back to you, its not my problem. If you want to have insurance, or tracking, etc. then figure out the cost and add funding appropriate to cover those costs.
Fifth, look, I'm not a professional and I'm not asking to be paid for this. The replacement sockets are coming from used, crashed, abandoned motorcycles. You are the one doing the final installation and I have no knowledge of your workmanship skills. Don't come back to me if your lights fail and you get crashed. Don't come back to me if your wiring short circuits and the subsequent fire consumes your pride and joy. Don't come back to me for anything! Its MY solution to a fundamental design flaw with the bike. I'm willing to share my fix. YMMV!
Sixth, if you ever come across a wrecked or parted out EV, please be sure to grab all the tail lamp parts so that they can become a part of the recycle service and can replace one that gets hideously melted from this design failure. I do have a few spare reflectors. If yours are totally destroyed for some reason, I can sell you one of these extra units.
The labor is free. Lots of very nice Guzzi people worldwide have gone out of their way to be very nice to me over the years. Chickens come home to roost. This is my version of trickle-down economics. I wouldn't be averse to accepting the gratuity of a fine beverage at our next rally meeting.
Patrick Hayes
Fremont CA