KOTM Jun 2008 antditty3436

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Old 04-23-2011, 11:07 PM   #1
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Join Date: Jan 2005
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Default Coil Relay Mod

OK I did this mod tonight and thought I would do a pic intensive walk though..

What you need:

Crimp connectors, if you dont have an assortment, you need:
1 red female spade
1 yellow female spade
3 blue female spade
1 red ring (3/16 ring diameter)
1 blue ring (3/16)

12VDC relay.
Inline fuse
About 8 feet of wire, I chose 12 AWG (the 12 foot roll was pretty cheap)
About 8 inches of black wire (I used a scrap of 18 AWG)
Shrink tubing, soldering iron, good strippers, crimp tool, electrical tape.
Coffee optional but recommended.. (that is a nice organic Sumatran Italian roast)

Now this isn't the relay I wanted to use. I wanted to get fancy and use a fog light relay. 1. because they are generally heavy duty. 2. they have two outputs.. But this one was nice because it has a mounting lug for an M6 screw..

First I crimped a red female spade and a ring on each end of the black wire.

Then I cut two pieces of the 12 AWG 8 inches long

I put two wires into a yellow female spade.. If I had the relay I wanted I wouldn't have had to do this..

The other end gets a blue female spade. Now I should point out I always use the smallest spade crimp I can fit. 12 AWG will barely fit in there. Here is my trick:
I untwist the wire, making them as straight as possible. This allows you to fit a smaller crimp connector. This makes for a tighter connection and much more wire to connector contact..

Now for the fuse and power wire:

A blue ring:

Here is how I spliced in the fuse..

I untwisted the wire like above.. Then pushed the wires together..

Twisted them again..

This makes for a very "slim" splice...

Now don't skimp on the solder..

Cover the solder connection with a few turns of tape.

Then another layer. I added a few "stubs" of shrink tube because I wasn't sure the larger tube would shrink tight..

Finally cover the tape with shrink tube

Now I always solder my crimp connections. You need a $200 ratcheting crimp tool and crimp connectors that cost a lot to get away with just crimping. This is why you should strip the wire a little long..

The wire is not only soldered onto the end, but the solder wicked into the barrel. This is better than factory. Yes the plastic bit melted a little, but we fix that next..

With shrink tubing.. This also insulates the connector. They make insulated connectors, but they might not fit into the relay..
All the crimps got soldered and shrink tubing..

The relay should have a diagram something like this on the side:

The box with connections 31 and 32 indicates the relay coil.
The drawbridge is the relay "switch"..
These are pretty universal. Thought some might actually have a spiral to indicate the coil..

Now the install.
The black wire is ground.
The spade goes on one side of the coil (31 or 32 as above)
The ring goes under a screw. I'm using one of the two open M6 holes under the front tank mount.

My yellow "splitter" connects to the switch (#45 or 46).

One the other ends of the splitter go to each coil replacing the orange wire.

One of the orange wires from the coil connects to the other relay coil connection.

Pull the fuse from the holder.
Hook the ring to your battery, route the fuse so you can get at it..
Since I chose stylish yellow wire I didn't mind of it showed. So I ran it down along my starter wire, up the clutch cable and over to the relay.
However you chose to run yours be sure it is well secured and away from moving parts..

Once the power wire is run, crimp, solder and shrink tube the last female spade, and connect to the other switch connection on the relay. (#45 or #46 above) Install the fuse. I suggest a 10 amp fuse..


When you turn on the ignition you should hear or feel the relay kick in..

This is the voltage on the old wire.. Not too bad..

Here is the voltage on the new set up:

You results may vary..
Now as I noted in the other post..
Even though this is one volt more, it can translate to as much as 10,000 volts at the spark plug.
Another thing to note, even though my bike is a '95 I just went through the whole wiring harness last winter. The entire thing was opened, inspected and any suspect wires replaced, factory splices soldered etc..
That might be why I was only down .95 volts.. But if a harness that was better than factory can get improvement, that says something..
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