Relay mod - Main or coils only?

[Guest]

Howdy folks. While I'm waiting for the umpteenth coat of primer to dry, I've been working on my electrical situation a bit. This is my 81 gs650gl.

I'm installing a new fuse box with a cover that takes modern ATO/ATC fuses. I remember there being a mod like the coil relay mod that was supposed to basically turn the ignition switch into a trigger for a relay that would power multiple things. The idea was to prevent burning up the ignition switch. Am I remembering it wrong, or was this a mod? I may be thinking of the coil relay mod instead, which I understand and will be doing soon.

[Steve]

I have done basically what you are starting: replacing the fuse box. I have done that to all four of our GSes, but I have used the Eastern Beaver box. I have also installed ONE relay, I guess you could call it a "main" relay.

The EB box has two fused outputs that are unswitched (hot all the time). I use one of them to power the ignition switch, then use the switched wire from the key to activate a relay that powers the other six fuses in the box. I have not measured the voltage at the coils, but I can say that I did not have any problems before, and it can only be better now.

In my opinion, the coil relay mod was sort of a "Band-Aid". It only fixed ONE issue with low voltage. There was also a "headlight relay mod" and other "relay mods", why not just install ONE relay so the new fuse box gets proper voltage from the battery and/or R/R, you won't need any other relays.

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[WilliamGLX81]

Yeah, that's what I'm envisioning. I was hoping there was a walkthrough. I can probably deduce from the wiring diagram and with a multimeter what the hot/switched parts are.

How much amperage does a relay like that need to be able to handle? 30A?

[WilliamGLX81]

Looks like (if fuse 0 is the aux always hot fuse), fuse 1 feeds the ignition switch, which in turn feeds fuses 2, 3, 4.

Based on the wiring diagram, I'm thinking that the orange wire coming in from the ignition switch can become the trigger.
Essentially, I'll move fuse 2 and run +12V to a fuse, then to the fused side of what is now fuse 1.

Wiring then would be this:
+12v to 10A fuse to ignition switch to pin 86.
Ground to pin 85

+12V to 30A fuse to relay Pin 30
pin 87 to Fuse +12V block input.

I think that's right.

[posplayr]

I know this is a link to the SSPB Install thread, but at the bottom of this post are instructions for modification of the wiring to the Kill switch for basically what amounts to the Coil relay Mod. The same process is used for the SSPB IGN trigger and for your modifications as well. If you use the output of the ignition switch you still have several connectors and the kill switch left in the circuit.

http://www.thegsresources.com/_forum/showthread.php?216224-Solid-State-Power-Box-STANDARD-INSTALLATION&p=1965977#post1965977

This is an old thread with writeup on using the spare wires in your harness if you rewired your R/R as recommended (with the stator going direct and getting rid of the headlamp loop)

http://www.thegsresources.com/_forum/showthread.php?141055-Yet-another-Coil-Relay-Mod-(with-Dyna-S)&highlight=Relay+Mod

[WilliamGLX81]

Why eliminate the headlight loop? I thought the load from the headlight damped that leg (yes, it works poorly, but it works).

I'd rather keep the kill-switch and all other wiring as is rather than modify it. What I really want to do is eliminate the voltage drop and length of wires from the +12 to ignition then to every other circuit.

[posplayr]

Why eliminate the headlight loop? I thought the load from the headlight damped that leg (yes, it works poorly, but it works).

I'd rather keep the kill-switch and all other wiring as is rather than modify it. What I really want to do is eliminate the voltage drop and length of wires from the +12 to ignition then to every other circuit.

That is what I explained how to do.

The headlamp loop tends to melt your connectors going to the headlamp switch (not particularly good feature). You can read all about it in the links provided.

[Steve]

There is no "damping" in the headlight leg. There are two separate circuits controlled by the headlight switch. One controls the current from the battery to the headlight (and actually causes the light to come ON), the other one is the third leg from the stator. The two never cross (unless there is a minor disaster).

The purpose of eliminating the "headlight loop" from the stator leg is to remove several feet of wire and about 9 connections (possible points of corrosion) from the circuit.

Since the US Department of Transportation mandate, any motorcycle manufactured on, or after, January 1, 1979 must ensure that the headlight is ON, once the engine is running. The means of ensuring that was up the manufacturer, and they differed some. Regardless, we then had different needs than the rest of the world, as far as wiring harnesses were concerned. Suzuki's solution was to simply change the sub-harness that went to the left handgrip. Instead of routing a stator wire up to the headlight switch, it made a U-turn right after the connector and was sent back down to the R/R. Since each of those connection points has a potential for corrosion, it is best to eliminate them and just wire the stator directly to the R/R.

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