Coil relay mod long term results

[Northern Mike]

I know the coil relay mod has been used for some time now by many.
Any long term issues with using mechanical relays for those that had the mod for a while?

[Steve]

I have not done the "coil mod", but I do use the same relays for other things, and have had no problems.

My personal thought is that if the coil voltage is low, the rest of the bike probably is, too. Rather than use a bunch of relays for the individual circuits, I use ONE relay to supply fresh power to the fusebox, using the ignition wire to trigger the relay. That way, the whole bike has the advantage of better power.

Did this to my wife's bike about 10 years ago, that relay is still there, still doing its job. I did my bike about 5 years ago (along with an Eastern Beaver fuse box), still going strong. My son's bike was also done about 6 years ago (also with Eastern Beaver fusebox), still going strong.

The relays are rather robust and are being used well within their power handling limits, the only real concern would be weather protection. If they are under the tank or seat, that is not an issue, but you can get sealed relays, if you wish.

.

[jabcb]

Cars have been using relays for decades. Don’t think I’ve ever had a car relay go bad.
So you just need to use a good quality relay intended for cars & bikes.

[salty_monk]

Nope... I use for other stuff on my KLR too & that's been in a lot more "bouncy" situations

Easy to carry a spare (cable tie it to the frame somewhwere) although there is some risk that if one went back so would the other I guess...

on my 1000G I used to carry a short jumper cable with two male spade ends, pretty simple to pull out the relay & jump either from the trigger to the output to give a switched live to the coils (back to stock -and your low voltage - basically) or jump from the constant live to the coils direct (remember to unplug the jumper cable when not running if you do it this way or they'll overheat whilst it's sitting). One or the other method would surely get you home (or to just about any parts store where you could get a new relay).

[mmattockx]

Any long term issues with using mechanical relays for those that had the mod for a while?

I wouldn't say mine is long term, but I have over 7000km and a couple seasons on the coil relay on my 1100E with no issues.

Cars have been using relays for decades. Don’t think I’ve ever had a car relay go bad.
So you just need to use a good quality relay intended for cars & bikes.

I've never had one go bad, but I do know of some that have. It isn't a common issue and not something I would worry about on a regular basis. If the relay on my 1100E ever goes bad I will just replace it with another one of the same and carry on.


Mark

[bwringer]

I would DEFINITELY use sealed relays. I've done this on several bikes over the years. No issues as far as I know. I use commonly available 40amp relays, so the amount of current used on a running bike is well below the relay's limits.

I have seen issues with unsealed relays -- they will eventually corrode and fail on a bike used in the real world. Unsealed relays are meant for use inside cars, or in weather-protected boxes.

I've also seen issues with improperly wired relays. The markings are hard to see, so it's important to stay organized. If you have a little room, using a relay socket helps.

I also have a relayed circuit on all my bikes that runs the phone charger, heated grips, etc. I have the memory of a goldfish in some ways, and using a relay ensures that I won't leave the grips on or something.

As noted above, you could carry a spare relay or a wee jumper wire just in case (you can also strip the covering and jam two female spade connectors together in a pinch). You can get good sealed relays at any auto parts store (they're usually found over by the auxiliary lighting), so a patch only has to get you to the next town with at least one stoplight.

The other thing to remember is that you still have to eliminate as much of the voltage drop as possible -- go through the entire wiring harness to inspect, clean, and protect ALL the connections. Don't just patch around a significant voltage drop with a relay. Some voltage drop, maybe half a volt or so, is normal even with everything clean and working well.

Another modification many folks have had success with is running the headlight with two relays (one for low and one for high beam). The headlight circuit goes through a lot of connectors and switches along the way, and even on a brand-new bike you can get a worthwhile boost in available photons by eliminating the "normal" voltage drop.

[Hinermad]

I have seen issues with unsealed relays -- they will eventually corrode and fail on a bike used in the real world. Unsealed relays are meant for use inside cars, or in weather-protected boxes.

I had a factory relay on my Triumph fail. I replaced it with a cheap automotive relay and moved it up under the tank to help keep it away from road dust, but I got rid of the bike a few months later so I don't know how long that particular hack lasted.

I assume relays need periodic replacement like light bulbs. I use a socket, or at least some quick disconnects, whenever I put one in a circuit.

[posplayr]

This thread has touched on an area, that probably needs a poll to see if we can get any reasonable info on relay reliability. Relays are inherently mechanical devices which makes them susceptible to vibration and heat cycling (electronics are as well). Based on what I'm reading here, we can probably guess that a mechanical relay is pretty reliable in normal service on a car. Relays are also used on bikes, but you cant just take that as a blanket approval of relays in any situation. The primary concern would be mounting and location of the relay.

In my opinion, it is well worth mounting your relay with some shock/vibration isolation so that the engine vibration does not transmit directly to the relay. You can do this by mounting the relay using a piece of thick rubber/plastic (like a piece of inner fender well). You want to allow the relay mount to flex so that the relay does not move with the engine/frame vibration. How much this helps is hard to quantify, but it is certainly not going to hurt. It will give you an environment closer to an auto. Heat is another concern, so I personally have mounted relays near the battery box where a stock ignitor might be located. In fact, teh battery box it self is a good place as it is shock mounted and relatively heavy (due to the battery) and adding secondary isolation should improve the isolation even more.

And I concur on the sealed relay choice. Keeping water out is going to maintain your contact resistance which is the whole point of the relays in the first place.

[GabrielGoes]

I have not done the "coil mod", but I do use the same relays for other things, and have had no problems.

My personal thought is that if the coil voltage is low, the rest of the bike probably is, too. Rather than use a bunch of relays for the individual circuits, I use ONE relay to supply fresh power to the fusebox, using the ignition wire to trigger the relay. That way, the whole bike has the advantage of better power.

Did this to my wife's bike about 10 years ago, that relay is still there, still doing its job. I did my bike about 5 years ago (along with an Eastern Beaver fuse box), still going strong. My son's bike was also done about 6 years ago (also with Eastern Beaver fusebox), still going strong.

The relays are rather robust and are being used well within their power handling limits, the only real concern would be weather protection. If they are under the tank or seat, that is not an issue, but you can get sealed relays, if you wish.

.

Hey Steve,

I really like your idea if adding one relay instead of one for horn, coils, etc. wind up with like 20 relays lol.

Do you have a diagram you can share exactly how you get it from the ignition wire? or maybe explain:

85- Ground
87- To Positive Battery with Fuse
86- Wire from the kill switch?
30 ??

[GabrielGoes]

bump for steve lol - it really does sound like a good idea

[salty_monk]

You can use the original Orange/white wire that powers the coils as the relay trigger... that's what I've done every time I've done this.

I've not used the sealed ones but it make sense. I don't deal with a lot of moisture here....