Coil relay mod

[timebombprod]

So the past week or so I've been chasing down voltage loss from my coils and have been getting little by little back, but I'm still only at 7.5v at the coils.

Alot of people have been suggesting doing a coil relay mod, having the coils directly connected to the battery ensuring you get all the voltage from the battery.

Heres my thought, if that's how I have to get all the power to my coils, wouldn't there still be an electrical issue going on through the bike?

What's your thoughts on this mod? Would love input from somebody whos done it.

[metalfab]

You need to do a voltage drop test on the coils. That will help you find the voltage loss problem.

[timebombprod]

You need to do a voltage drop test on the coils. That will help you find the voltage loss problem.

That's what I've been doing, ive cleaned anything that goes with the ignition and I did gain about a volt back but in still at 7.5volts at the coils, assuming that putting the positive probe on the positive coil connection and negative probe on the negative connection to see the total voltage.

[zed1015]

Relay mod isn't needed if all the wiring connections etc are clean and maintained.

[timebombprod]

Relay mod isn't needed if all the wiring connections etc are clean and maintained.

That's my exact thoughts, I didnt really want to do it because I know that would mean I still have a connection issue, the thing is I've cleaned everything that goes to the ignition setup, and while I gained a bit of voltage back, I'm not even close to where I should be.

The only thing I haven't touched is in the wiring harness and that's where the killswitch wire attaches to the coil wires. I can ensure everything else has been cleaned

[zed1015]

That's my exact thoughts, I didnt really want to do it because I know that would mean I still have a connection issue, the thing is I've cleaned everything that goes to the ignition setup, and while I gained a bit of voltage back, I'm not even close to where I should be.

The only thing I haven't touched is in the wiring harness and that's where the killswitch wire attaches to the coil wires. I can ensure everything else has been cleaned

One of the main culprits is the actual kill switch on the bars.
If not already done it is the copper contacts in the switch that get gummed and tarnished .

[timebombprod]

One of the main culprits is the actual kill switch on the bars.
If not already done it is the copper contacts in the switch that get gummed and tarnished .

It has been cleaned externally but with the soldered bits and the actual wire those have not been replaced.

[Sandy]

Relay mod isn't needed if all the wiring connections etc are clean and maintained.

So true. While there are good points for a relay mod like less load on switches I don't consider it a fix for low voltage but more of a work around for not fixing the original issue. Contacts in the bottom of the ignition switch are usually bad and overlooked as well.

[timebombprod]

So true. While there are good points for a relay mod like less load on switches I don't consider it a fix for low voltage but more of a work around for not fixing the original issue. Contacts in the bottom of the ignition switch are usually bad and overlooked as well.

Completely agree, I did make sure to clean those contacts, mayne I'll check where they touch aswell

[Grimly]

When you say 7.5V at the coils, is that with the coil-to-ignitor lead disconnected?

[timebombprod]

When you say 7.5V at the coils, is that with the coil-to-ignitor lead disconnected?

Probe on positive and negative connection on coil connections, how should I do it? Ignitor is gone

[metalfab]

That's what I've been doing, ive cleaned anything that goes with the ignition and I did gain about a volt back but in still at 7.5volts at the coils, assuming that putting the positive probe on the positive coil connection and negative probe on the negative connection to see the total voltage.

A voltage drop test walks you through the wiring to the coil, and will locate the exact spot where the drop occurs. Possibly you need to take a look at the voltage drop test process, it is only way to effectively find this type of problem.

[timebombprod]

A voltage drop test walks you through the wiring to the coil, and will locate the exact spot where the drop occurs. Possibly you need to take a look at the voltage drop test process, it is only way to effectively find this type of problem.

I have been doing voltage drop testing, I'm gonna have to test the ignition switch connections and the only other thing would be where the killswitch and coil wires meet. I know in losing a little over a volt between the fusebox and killswitch, both have been cleaned up but I still do have that loss making me think its in between. I just hate to own the harness to get to that bit.

Everything i cleaned wasnt really in bad shape at all and everything performs as it should.

[timebombprod]

Well, after cleaning all I could, and tracing the voltage loss, it came to my dyna S, called ul dynatek for a resistance test and it passes the test aswell as the coilpacks. He said hes gonna send some stuff out to ensure i get 12 volts to the coils and ignition, and I asked if it's a coil relay mod and sure enough it was.

I'm gonna go in that direction, because honestly the only way I see getting voltage back is replacing more things and resoldering things and I'd just rather do this since my ignition is the only thing that keeps failing on me.

We'll see how it goes and hopefully I can ride without worry after this. The only thing left (never is with this bike) is doing the fork seals and getting my horn setup correctly.


Will give an update when the mod is finished and successful

[winmag4582001]

Just my .02
The wiring on old bikes is horrible. I eliminate the old wiring and go to a modern fuse box and centralize the ground point. I also upgrade to the Dyna ignition pickup and coils. It's much cleaner and simple. You can easily add a contact to your system for the coils only. Also, make sure the coils are grounded well. If there is paint or rust insulating the coils, they will be affected.
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