Givi Topcase Electrical Question

[Cap'n]

A good searching nets me a lot of threads about the phsyical installation of Givi racks, and I put them to great use. Got the topcase rack mounted last night in about 45 minutes with no issues whatsoever. Well, no phsyical issues.

I got the 52 liter topcase with integrated brake lights (and E21's for the sides). The instructions say, basically, "find the bike's tail light hot wire, use this little clip, and attach it to the case's hot wire. Then do the same with the ground wire." Thank you, Copernicus, how enlightening. I was once a residential / commerical electrician, so making connections and sorting out wiring diagrams in my head isn't a big deal, but I didn't work on DC.

The tail light has 3 wires: Black, Blue, and Yellow. The black goes to the outside of the lamp socket, which tells me it's the ground, no? That leaves the blue and the yellow, one for the running light fillament, the other for the braking filament. And on the flipside, the topcase has 2 wires, one black and one blue. So the final result should be "running = stock tail light, braking = stock brake light + case lights come on." Yes? So I'd need to figure out which of the blue and the yellow are which. But then there's the other wrinkle: Which wire is which on the topcase? They disappear into the lights, and aren't marked on the outside anyway. But they're single filament bulbs, so if they're like AC, it really won't matter - current goes through a filament and then grounds.

So I made the assumption first that they should be paired up, black to black, and blue to blue. I popped on the connectors, clicked on the topcase, fired the bike up, and got this:

Running: Tail light normal, topcase lights on.
Front brake: NO DIFFERENCE.
Rear brake: Tail light brighter, top case lights still on.

...

So I disconnected the topcase wires entirely and re-tried the bike, disturbed about the front brakes not tripping anything. SAME Result - no response from the tail light to the front brake, but normal response to the pedal. I took it around the street in front of the house, thinking (wishing) it had something to do with movement or speed, and it doesn't. My grizzled old Harley riding buddy tells me this used to be the norm, where the front brake didn't trip the light, but the back brake did.


Thoughts? You guys have always been very helpful - appreciation in advance.

[Lucky_Devil]

The front brake lever should definitely be triggering the brake light.

Check and make sure all of the wires are connected (and connected properly) at the throttle/switch housing.

If everything is connected properly, make sure the trigger for brake light is adjusted correctly (covered in the owners manual).

As far as the wiring goes, I would suggest downloading the service manual (for free - do a search here) and checking the color wiring diagram to determine how the Givi wiring should be connected.

[rennsport]

There is no difference between AC & DC for this exercise. Since you are a sparky, get your ohm meter out and check the contact points on the givi rack and the two wires and see which contact is wired to the black wire. My guess is that the black wire is ground, even in Italy. Do likewise with the ohm meter set for volts and activate brake and see which contact in the socket is hot.

[Jim Karam]

Switch the blue wire connection to the yellow wire, since you obviously have the Givi case lights connected to the "running light" of the brake light, not the desired "brake light". The Givi lights only light one way since, as you note, they are single filament lights. You have to choose how you want them to display. If as brake lights, they will NOT light continuously as running lights. For completeness, I'm attaching the FZ's wiring diagram extracted from the service manual.

[chiller]

i think you hooked up one of the wires wrong, black to black but i think your other wire from the box should go to the yellow on the bike...

reason being one of the wires is ground like you found out, one of the other is the 'running lamp' on the dual filament tail lamp, the other is the 'brake light' filament . so you've hooked up the power lead from the topbox not to the brake light but to the running lamp side of the bulb ... disconnect that lead and put it on the yellow, retape the wire on the blue ...

[04Fizzer]

It sounds to me that you have to make a decision. Do you want the givi lights as running lights or a brake light?

Edit: Also check the connections on the bars to make sure your front brake lever switch is plugged in.

[Cap'n]

I came to the same conclusion, regarding switching the Blue to Yellow. I want those suckers blazing when I hit the brakes, not just running all the time. It's the front brake not triggering anything that really gets me antsy. How in the hell did it just suddenly start once I plugged this all in? It makes me think I fried something, but how in the hell do you fry just that front sensor, and just by tapping into the rear lamp wires?

And THANK YOU for the wiring diagrams and help! I'm mounting the side cases tonight.

[Cap'n]

Just to conclude this, in case anyone else ever has this problem and searches the thread out, it was indeed what we thought it was. Somehow, my brake sensor switch wires were unplugged from the fron brake lever (?!), and the proper wires to connect to are the yellow and the black (not the blue and the black). The yellow is the "braking' lead, the blue is the "running lights" lead, and black is of course ground.

Got everything installed, and oh my god is it nice. I put a 30-pack of high life cans in that top box with plenty of room to spare yesterday. Don't judge me.

[04Fizzer]

Originally Posted by Cap'n

Got everything installed, and oh my god is it nice. I put a 30-pack of high life cans in that top box with plenty of room to spare yesterday. Don't judge me.

Leaves room for ice.

edit: Or more beer, or some good steaks.

[Cap'n]

When I walked out to the parking lot and looked at the case and the bike together, I said aloud "oh crap, this was a mistake... you got greedy." But I'll be damned if it didn't go in there, standing up, with room for another 12'er. I was already working out a scenario in my head where I asked them to hold it for me while I went home and came back for it.

Luggage is good.

[lharrellr6]

Originally Posted by Cap'n

When I walked out to the parking lot and looked at the case and the bike together, I said aloud "oh crap, this was a mistake... you got greedy." But I'll be damned if it didn't go in there, standing up, with room for another 12'er. I was already working out a scenario in my head where I asked them to hold it for me while I went home and came back for it.

Luggage is good.

We need pics ASAP of said beer in case.

[marke14]

Originally Posted by Cap'n

I put a 30-pack of high life cans in that top box with plenty of room to spare yesterday. Don't judge me.

[Cap'n]

Originally Posted by lharrellr6

We need pics ASAP of said beer in case.

Well, the beer is in the fridge (and in my hand), but here's two helmets in it:

[Lucky_Devil]

In what universe are you getting 60MPG?

[Cap'n]

I got 62mpg over 200 miles once, under great duress. Got to the border of NH, (headed for a weekend of hanging out at a friend's house on the coast of maine), and realized I'd forgotten my wallet. I think I had like $8 on me, and figured they'd loan me $10 when I got there. They forgot to leave it when they took off in the morning, so the $8 had to get me all the way home. I inflated the tires close to the max, babied the throttle unbeliveably, and killed the engine in downhill traffic all the way home, and averaged 62.

It ain't easy, but it's possible. Hell, even putzing around in VT below 65mph, I average in the mid/high 50's. Granted, hogging it out drops that figure into the low 40's, but still.