Topica Loopframe_Guzzi Archive


Subject: flaky electrical on Ambassador fixed; TIP

Author: William F. Dudley Jr.

Date: Sep 7, 2004, 1:07 PM

Post ID: 1717488956



My 72 Ambassador got flaky late last year and it's taken me this long
to sort it out, mostly due to being busy (and I have other bikes to ride.)

Flakiness here is defined as having the electrical system shut off for
2 to 20 seconds, randomly. Very disconcerting as you can imagine.

To make a long story short:

Opening up the ignition switch by bending back the three tabs revealed
that the switch had green fur growing on the copper bits. I cleaned
this up with a pot scrubber and put a light silicone grease on the
copper bits to try to prevent the fur from growing back. I also put
fresh Lubriplate on the detent plate.

Inspired by the article "Before and After, a Tale of Electrical Success"
by Tom Bowes in the MGNOC August newsletter, and also by the posts
on adding relays that have gone by on this list, I was inspired to
"help" the ignition switch by adding a relay in the dash board. There's
just room for an "ice-cube" sized horn relay from the local auto parts
store in there, right above the idiot lights. I chose to use the
relay to supply the "main" DC (to the ignition circuit and starter
solenoid) though on reflection, the lighting load is probably higher,
on average.

To do this, I wired the supply from the battery to BOTH the ignition switch
(30) and to the (30) terminal on the relay. The relay coil goes to ground
(there's a nice ground on the triple clamp used by the tachometer) and
the other end to the 15/54 output of the ignition switch. The relay
contact "load" side goes to the wire that used to attach to the 15/54
ignition switch terminal.

While not as complete a solution as the ones involving running a new
wire from the battery, this at least solves the problem of having ALL
the current in the bike go through the ignition switch contact. Now
just my lighting current plus the relay coil go through the ignition
switch.

I didn't measure before and after voltages as Mr. Bowes did, but at least
now my electrical system is reliable again, and I'd not hesitate to ride
my Ambassador across the US.

Bill Dudley
72 Ambassador
71 Norton Commando
A buncha old Hondas

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