Key switch or ??? 2001 california....light gone

[bdlwet1]

Riding home the other night and headlight goes out.  Get it home and start trying to find gremlin.  1- Light is good, fuse is good, relay.....don't know how to check, but get new relays and replace  the one I think (!) is the lighting relay.  take tester and look for shorts wire per wire on headlight.  Had added running lights and jumped wires to Bright side of harness so only came on when hit my brights.  Not the issue.  cleaned up wiring and checked  continuity...no short in 4 wire harness.  Then took harness apart in headlight housing and checked that had good continuity in wiring.  Put it back together and just the parking light in headlamp is working now !  Still can't get sufficient voltage to the headlamp......so my next issue should be the key switch.......anyone have any ideas ?  Just put 4000 miles on it in a great run June this summer.  Never an issue on whole trip.

[bdlwet1]

next step was checkiing relays....all resistance between 70-110 ohms across coils and they all switched with 12 volts applied.....check wires, cut wire mold and found broken wire...right side below chrome cover behind forks......_not gonna put chrome back, sharp edge, abrupt bend.  fixed broken wire with crimp joint.  Still no lights....checked continuity on swithc wire loom.....looks like hi/low switch is working......all relays 5 pin except for 1.....in fromt.....Diagram shows ALL have 5 pins.....why one only has 4 ?  buty iin looking at sockets 3 of them only have 4 contacts ??  would appreciate ANY insights on this problem !

[rocker59]

using the 5-pin relays in the spots with 4 contacts is fine.

is it possible that you've moved the relays and have a 4 pin relay where a 5 pin relay should be?

I wouldn't hurt to buy all new relays from Pyro Dan, while you're working this problem.

http://www.dpguzzi.com/relay.htm

[Kiwi_Roy]

As Mike says, you need a 5 pin in the Start relay slot, the normally closed contact turns on the headlight relay.
Replace all relays with the 5 pin type then you can switch them around.

http://www.thisoldtractor.com/guzzi007/schematics/2002_Stone.gif
Check for power on fuse 3 & 4 with the key On that will prove if the switch is working
It could be the ground has come off in the headlight, measure from the lamp pins to chassis only one should be hot, if all 3 re it's a grounding issue.

[twhitaker]

FWIW, Dan also sells a front brake light switch. 

[rtbickel]

Could the bulb have blown when the wire broke/shorted?

[Bill Havins]

Are you the only owner of this Guzzi?  If no, did the earlier owner(s) set up the headlight on it's own independent relays?

A broken wire is said to be an "open" circuit, not a "short."  But if the decorative chrome severed the insulation and the wire it likely "shorted" the voltage to ground, which surely blew a fuse "somewhere."

If an earlier owner set the headlight up with its own independent relays, and if they did it well (think "near-overkill") then he/she powered the headlight relays with a fused DC supply that connects straight to the battery - on my Guzzi that would be the fuse that blew when the decorative chrome shorted the severed wire to ground!

Look for voltage with the key turned on - continuity can be misleading at times, especially when you are testing a circuit that has a route to ground (through the headlight bulb, the high beam indicator, the relay if the power isn't on, etc.).

Pure stream-of-consciousness, above.  May all be wrong and worth less than two cents.

Good luck!

Bill

[Steph]

I just fixed my high beam only issue.
Within the LHS high/low beam toggle switch there was a bad contact.
First cleaned-up the sunken (lower right) high beam terminal:


Then it only worked after I scraped off this terminal -I have my high beams back!

[bdlwet1]

Well........Looked at my switch today, inside was superficially OK....(only work 1/2 day on Guzzi due to lotta honey do's) , and did NOT take it completely apart but checked on harness where diagram denotes different wires for hi/lo and found continuity changed when hi/lo switched on handle.  But after fixing broken ground on harness going to key switch I have found that light harness from instrument cluster is grounded on two , (out of 4) contacts.  Doesn't look right two sides of 4 pin harness goes to ground.  All wires from key switch look good, no continuity between.  I did look on relays where 4 and 5 pin intersect, but found no reason I had 4 out of 6 as 5 pin.  I did exchange some 5 pin for 4 so I will try to put all 5 pin and see if it makes a difference....on  Wiring Diagram all relays show 5 pin switch mechanism which I ran 12 volts across coils to check.  But weird is at light (H4) shows continuity across 3-way AMP connector....will put battery in old analog meter and check ohms as I think there MUST be some continuity in lighting circuit against element in light.  And yes, bought my Guzzi used with 25,000 or so miles in late 2012...now have 40,000+