Wiring question

[BwanaDik]

I've studied numerous threads about the Soltek install. I'm going with this switch method but 1FJR's comment

"When I got the lights, I did not want to use the giant switch that came with them. I decided to find a switch to fit that opening on the housing on the left handlebar. I found a switch from DIGI-Key (CH755-ND) that was only slightly larger than the opening. So with some carefull file work I was able to make the switch fit. My uncle the family electronic genius suggested that I install a resistor (1K 0hm rated at 1/2 watt) between tabs #85 and #86 on the relay to help keep the switch from burning out. I just sodered it in place. "

has me a little concerned. He's running Hella 550's, I don't know what the amp draw is. The Soltek has 10 amps starting then 3 amps running (I'm assuming that's EACH, for a total of 20 amps starting via my Fuzeblock). I'm infering from his comment that he is using a relay to power his 550's and that the switch simply triggers the relay.

So....

Do the Soltek's need a relay, switched by the small switch in the flash-to-pass button? Or can they go straight from the Fuzeblock, thru the switch, to the lights?

What is he talking about with the resistor (Alan?)? Do I need to install one? I'm assuming this is across the terminals of the relay, not the terminals of the switch?

 

[canyonman]

I would use a relay to keep the current off the small contacts in the switch (think ignition recall).

Now the resister has me wondering, I know when you remove the power from a coil the magnetic field collapses inducing a large voltage spike that can eventually burn out your contacts in the switch.

In the industrial applications that i am familiar with we use small capacitors to shunt that spike to ground.

Double check with your uncle on that one, a capacitor will pass a pulse but not constant DC power.

Thats my 2 cents and that's about all it's worth

Are the pin#s you listed the contacts for the coil in the relay?

 

[Silent]

Use a relay.

 

[BwanaDik]

Unfortunately not my uncle. 1FJR's! I quoted him from another thread (hit the underlined "this" in the original post)

Yes, from Constantmesh on another thread

Relay

"My five terminal 12V 30A relay has the following terminals:

85 -- one side of coil

86 -- other side of coil

87 -- one side of normally open contact

87 -- one side of normally open contact

The two 87's are connected/bussed together inside the relay

30 -- other side of normally open contact"

So apparently he put the resistor across the coil. Possibly this should have been a capacitor (same function as ignition condensor? Remember those? )

 

[canyonman]

Possibly this should have been a capacitor (same function as ignition condensor? Remember those? )

Yes I do, same thing. and in the applications I was referring to we are using large control relays, motorstarters, etc. big coils.

I think maybe BMW has a computer that is sensitive to the spike but I never heard of anyone being overly concerned on a FJR. I have a single hella de micro that uses a relay in the supplied harness (much less draw than a pair of solteks). I don't think a relay would ever be a bad thing.