Help Needed with electrical wiring on VN800 & Guage lights

[Joram]

If anyone has followed my custom guage install thread for the VN800, I am almost done with it.

Now I am faced with the problem of connecting up the lights inside the guages. How should I go about it? Which ciruit should I connect to?

At first I though to splice into the wires that run the dash lights. This would make the guage lights turn on and off with the dash.. Sounds good to me...

The autometer guages I have suggest adding a 3amp fuse to each guage. Will this overload the fuse the dash lights are on? I don't know.

Second thought was to install a relay for the new guage lights and have it trigger off a tap from the dash lights. Any thoughts on this?? Would this be preferable to just tapping the line and adding the lights?

Dose anyone know exactly which wire I would tap to get the dash lights?


Look forward to hearing the comments on this one.

[jeffs99vulcan]

OOOH. This is about the only thing that is second to carbs for me... I can run wiring, and wire a house, but when you get into relays and fuse loads... nope. Hmmm. I can't remember who best I came across for this... Cos? Jamie? We'll round 'em up!!!

DO you have the service manual?

[Joram]

Yes, I have both Service Manual and Clymor, but the previous owner or 2 has played around in the wiring harness. I can not count on the colors being 100% correct.

I have a camera full of pics to load up. I started at one end and I am working my way back to the rear tire.

I am hoping to have all the mods on the bike this weekend except for the hard saddle bags and grampsizing the air intake.


I learned the hard way last weekend trying to buttin it up that if the wiring is screwed up you have to undo it all again. This time I plan to do it with help first

[jeffs99vulcan]

I have a crap load of stuff to install too... all the stuff I was ordering all winter and having shipped to my parents in Florida is now here!

And now that I know I'm not deploying until January, it's like CHRISTMAS around here! That, and I need tires BAD, so I'd like to get them before I do the sprocket change... No chance getting them before tomorrow though! I'll have to get them shipped to Ogdensburg and go pick 'em up...

[Greying]

when I added lights to my bike, I used a relay. The power comes from the battery and I just used an ignition circuit through a toggle switch to trigger the relay. This way, my lights are never left on with the ignition off. You could use the dash light to trigger a relay and not have a toggle switch. You relay trigger will only use a negligible amount of power ans wont blow any fuses. My only recommendation is get a good relay.

[cosmicsclassic]

Hey Joran, Jeff , how ya'll doing? What are you trying to wire Joram, gauges? I've not seen your post on this. What kind? oil? temp? electric or manual? Nice to see you back Jeff, it was slow round here, Joram had your back though.

[jeffs99vulcan]

Hey Cos!!! Good to be back... ya, that Joram, he's OK. No matter what all those other guys said...

[cosmicsclassic]

[quote=Joram;1575654]
At first I though to splice into the wires that run the dash lights. This would make the guage lights turn on and off with the dash.. Sounds good to me...

The autometer guages I have suggest adding a 3amp fuse to each guage. Will this overload the fuse the dash lights are on? I don't know.

I'm guessing you just want to wire up the dash lights in the gauges, what I'd do is go in the headlight bucket find the wire that operates one of the running lights to one of the turn signals, I beleive it's lite blue, tap it , put in a fuse and holder there in the bucket (one should do, 3 or 5 amp) then run the wire to your dash lights. on and off with the switch.

[Joram]

If you want to see what the guages look like try this link Custom Guage Project on VN800A


Yes, I want to wire up the lights in the guages to come on/off with the lights in the speedo dash.

Since I have the whole bike torn down, I thought I would just add a relay and run a seperate fuse for the gauge lights. Keeps it simple.

I was reading over the Service manual and thought that using the Red/Black wire from the dash lights as the trigger for the gauge relay.

What do you think of that?

[RichLockyer]

I just ran my lights to the same power source I used for the gauges themselves... Relay connected directly to the battery, triggered by the running lights.

I did this because one gauge is a voltmeter, and I was consistently reading 1 volt low on my digital meter comparing the headlight bucket accessory lead to the direct battery connection.

[Joram]

The gauges had 4 lines in them. 1 for the sensor, 1 ground, 1 power and 1 power for light.

I tied the 2 power lines togther in each gauge. Figure I could use a common frame ground for all.


Rich, If I run a relay, can I connect all the power to just it and then trigger from either the dash lights or running lights?

[RichLockyer]

Originally Posted by Joram

Rich, If I run a relay, can I connect all the power to just it and then trigger from either the dash lights or running lights?

That's what I did. Ran 18 gauge from each gauge + and lamp + to the relay, then fused the relay hot side at 10a.

Just because the gauge's instructions say to run a 3a fuse doesn't mean that the device actually draws that much. 3a is 36 watts at 12v... a tail light is typically around 5 watts and gauge lights MIGHT be 2 watts.

The idea of a fuse is to protect the wiring in the circuit. If the device fails and draws too much, you want the fuse to go before the wiring burns.

Even more important in a vehicle where movement and vibration are a problem, the fuse should be as close to the power source (battery) as possible. A fuse in a fairing is doing nothing to protect the wiring between the battery and the fairing. A short in that leg will burn the wire and potentially damage the battery.

We're conditioned to expect a fuse "at" a device from TVs, stereos, etc... but it's easy to forget that the house has a 100 or 200 amp main breaker on the service, and the wall outlet has it's own 15-20a breaker on the panel before the wiring goes out to the home.


Personally, I ran a 30a circuit from the battery to the triple clamp area using 8ga wire. I tap into this circuit for various accessories using appropriate fuses for the size wiring that I am running to the accessory.

Keep in mind... the ground wire carries just as much current as the hot wire.
A frame ground is fine, but you don't want to plug four running lights, an airhorn, and a stereo amp all into the accessory ground wire in the headlight bucket. It's a ground, but it's still part of a 10a circuit.

[Joram]

Thanks Rich...


I am going to run a seperate relay for my Stebel Air Horn, gauge lights/guages and my running lights.

Putting in fuses close to the battery and relay.

[RichLockyer]

Originally Posted by Joram

Thanks Rich...


I am going to run a seperate relay for my Stebel Air Horn, gauge lights/guages and my running lights.

Putting in fuses close to the battery and relay.

Ya know... a secondary relay for the horn is not a bad idea.

Stock, the horn only has power when the bike is running, but when an air horn is installed, we add a relay to reduce the load on the stock switch.
Problem is, that relay is usually exposed, and I've read 2 reports over the last 3 years of someone being awakened by their horn or going out to their garage, finding the battery dead, and upon connecting the charger, the horn starts sputtering (charger doesn't have enough to fully drive the compressor).
In both cases, the relay had become wet and the contacts inside had shorted. Since the relay is connected to the battery, the horn blew and the only way to stop it was to pull the relay.

Mine is mounted high on the downtube with the contacts pointed down, so any water that might get in is free to drain out the same way, but I can see someone mounting it with the contacts up, which provides no exit for any water that might get in, and the actual contact points are near the opposite side of the cover as the blades, so as water builds up inside the cover, the points would eventually become submerged.

I think my mounting is fine (and we don't get a lot of rain anyways), but a secondary relay that switches the battery power to the primary relay would provide an extra measure of protection.

[Joram]

Rich,

I have the relay for my running lights triggered from the Blue/Yellow off the head lamp.

Can I use the same Blue/Yellow to trigger the guages/lights?



Also, on my Stebel horn, I used 12 awg stranded wire for both the ground and 12v. Will this be suffiecent along with a 20a fuse for the horn?

[RichLockyer]

Ya, 12ga is fine for 20a.
The horn is so intermittent that it could probably survive on 18ga without burning anything up, but I wouldn't do it.

Trying to remember which one the blue/yellow is... if it's ahead of the hi/lo switch, it'll work fine, but your gauges will be dark until you crank the starter. That's how mine are wired, so I can turn the key on to listen to the stereo without lighting up the gauges and draining the battery with the voltmeter and oil pressure gauges.

[Joram]

Rich,

I just double checked some things and I actually used 14 awg wire from the battery to the fuse and then the relay on the horn.

Should I change this out?

[RichLockyer]

14 is pushing it... it's really spec'd to 15a max, but it's not going to burn up no longer than the horn compressor is running.
Dead short is going to blow the fuse before the wiring burns.

[Joram]

In your opinion for the horn, the 14 awg with a 20a fuse will be OK then?

If it makes better sense to rewire then I will. I would prefer not to waste the time and materials, but safty and a fire proof bike does count for someting

[RichLockyer]

I don't think it will present a problem. Personally, I'd swap it out to 12, but being an electrician/tech, I've got easy access to cheap wire.