Bonneville America Forums Forums Technical Forums Custom Corner Wiring stuff-up ... help!

I just installed twin Stebel Magnum horns using the relay wiring kit from SRS Chrome.

The horns work great but I get a momentary flash from both the dashboard lights - neutral light, oil light and indicator light - when I use the horn. I must have connected it wrong somehow.

Is this a potential issue (computer meltdown)?

Any ideas on what would cause these lights to go on when the horn is activated?

Sounds like a job for the Sandman!

Dont have a wiring dia but sounds like you have picked up the return to neg of thes lights instead of a positive supply for the relay from the battery, did you notice if one side indicators also flash ? you must be earthing these circuits somehow.

I'd have to agree - it sure sounds like the horn is grounded through a dash light circuit. Will it hurt anything? Probably not, but it would be a good idea to change it. Not sure what would happen if the horn was sounded while a dash light was juiced up. Maybe nothing. Not sure.

NIbiker - I didn't notice if the indicators (blinkers) flashed as well - and I have now disconnected the relay till I solve this.

The horns are earthed to the frame.

The existing horn wiring connects to the relay (possibly the positive and earth are the wrong way round on the relay - if it makes a difference).

The relay gets a direct feed from the battery and direct out to the horns (possibly these input/output are the wrong way round on the relay and need to be swapped - if it makes a difference).

These are the only possibilities I can think could be wrong.

Although - I did have to 'persuade' the dash wiring loom to fit inside the dash when reassembling (it made a tight dog leg). But I can't see that would be the cause because then the problem wouldn't just be isolated to the horn use - it would manifest at other times as well.

The horns are earthed to the frame.

Ok

The existing horn wiring connects to the relay (possibly the positive and earth are the wrong way round on the relay - if it makes a difference).

I dont think that would matter, this is the two coil connections of the relay.

The relay gets a direct feed from the battery and direct out to the horns (possibly these input/output are the wrong way round on the relay and need to be swapped - if it makes a difference).

This would not matter, this is the switch connections of the relay, I would recomend going through a fuse though.



Although - I did have to 'persuade' the dash wiring loom to fit inside the dash when reassembling (it made a tight dog leg). But I can't see that would be the cause because then the problem wouldn't just be isolated to the horn use - it would manifest at other times as well.

I think your problem must be in there, guessing you put the relay in there, the horn button on the Lh bar I think operates by grounding the horns,(now your relay) this wire on your relay must grounding out the other circuits.

Check over the connections and if thats no good I would disconnect the new horns from the relay and also the live from the battery, see if the relay clicks when you press horn button, and of corse if you short out the two wires you disconnected new horns should sound. may help you find what side the short could be on.
Happy hunting.

Thanks NIbiker.

I should have mentioned there is a fuse between the battery & the relay.

The relay is not under the dash. It's tied to the frame under the tank.

>>I would disconnect the new horns from the relay and also the live from the battery, see if the relay clicks when you press horn button<<

I don't understand the purpose of this test. Don't we already know the relay works because the horns worked when I pressed the horn button?

But now I'm at a loss to where the problem is (if it is not the polarity of the wires connected to the relay).

Well, just to see what side of the circuit is causing the fault, process of elimination. if you still have the fault after disconnecting the supply from the battery (unlikley to be the problem as you say) and the wire from the relay to your horns ( unlikley but possible ) then the problem must be with the coil side of the relay, or under the dash.

Some more info for a 790cc america so the colours might be wrong.

Fuse 7 supplies 12v to
Direction indicator unit,
Front and rear break switches,
this is on a orange/green wires.
It also supplies one side of the horn with 12v on a black/blue.
the other wire at the horn black/purple makes its way to the horn button, pressing the horn button connects this to a black wire that should be to ground and so the horn activates.
now here is the connection (no pun intended), the black wire in the LH bar for the ground for the horn switch is also the ground for the LH indicator, If this black wire was not grounded good pressing the horn button would put 12v on the indicator circuit for LHS and possibably feed other circuits as well.

I would have a look in at the LH switch connections 4, black/purple 12v from horn and 8 black ground for horn button and LH indicator.

I cant put the diagram on the post, hopefully somebody can.

There is a wiring diagram here.

What do you mean by the numerals 4 & 8 in "I would have a look in at the LH switch connections 4, black/purple 12v from horn and 8 black ground for horn button and LH indicator."?

I will check out the left hand control connections and their earth.

Could the problem be caused by a poor earth from the horns to the chassis?

I really appreciate your help here NIbiker - thanks mate.

OK - I figured out the numerals - they refer to this other wiring diagram here. and the wiring positions in the connector.

OK. All tests done.
Disconnected power side of relay. Still flash from dash.
Disconnected horn side of relay. Still flash from dash.
Relay clicks when only connected to horn switch. Still flash from dash.

Took wLH control apart - connections look fine. I have no idea where the 8 black ground connection might be found.

No flash from any indicators or any other light except 3 dash lights ...
the red oil light on dash, green indicator light on dash and green neutral light on dash.

Possible cause ...
These three dash light were replaced with LEDs. Could the sensitivity of the LEDs be activated by something really minor?

I have run out of time tonight so haven't checked the dash wiring loom yet.

OK. All tests done.
Disconnected power side of relay. Still flash from dash.
Disconnected horn side of relay. Still flash from dash.

Ok we will say that these two are Ok.

Relay clicks when only connected to horn switch. Still flash from dash.

I guess you mean that you only have the two original horn connections on the relay coil now, seems to make sense and ok.


Took wLH control apart - connections look fine. I have no idea where the 8 black ground connection might be found.

I think this connection is half way down the wires from the LH switch to the headlight housing, I found it there when I repositioned my indicators from the bars to my light bar. you could check the from theb awitch to the connector in the headlight.

No flash from any indicators or any other light except 3 dash lights ...
the red oil light on dash, green indicator light on dash and green neutral light on dash.

Possible cause ...
These three dash light were replaced with LEDs. Could the sensitivity of the LEDs be activated by something really minor?

The LEDs draw less current that the bulbs so it might be worth checking all your earths, the other thing is the indicator lamp polarity changes depending on L or R is switched, I dont think you can put an plain LED in there. try swaping it back to a bulb.

I have run out of time tonight so haven't checked the dash wiring loom yet.

I cant view your diagrams from this PC but they sound the same.

Sleep well.

Testing everything again and I noticed something important...

The LEDs in the dash flash momentarily when the horn button releases - not when it is pressed. This also occurs with the original horn installed and no relay connections. Swapping the polarity of the LEDs makes no difference. there is no flash when using the original bulbs.

I couldn't find the earth for the dash/handlebar controls to check that.

Sooo ... the flash is nothing to do with the relay. Seems to be the LEDs - sensitivity?

Any thoughts? OK to just ignore the momentary flash?

HUMMMM

Still sounds like a possible bad earth connection, but I guess if everything is working and there is no fuses blowing or smoke its ok, like you say meyby the LEDs are sensitive to some energy released when the horn is deactivated, it is a coil and a core afterall.

Anybody else with LEDs have same thing I wonder?

Guess you can say your bike has KERS like F1

Thanks NIbiker. I really don't understand the 'coil & core' comment or the KERS & F1 reference but I guess the former is about how LEDs work and the latter about some sort of gremlin or SNAFU.

I might take this LED question to a broader audience and address it in a separate post.

Thanks again.

This issue of flashing LEDs is resolved. Please see this thread here.
Thanks to all who helped.