Oxford Heated Grips - Need them re-wired

[CookMySock]

Is a diode a good idea or is the taillight/lights circuit enough to soak up a voltage spike before it reaches more sensitive electrical components on a modern GSXR?

It is always good practice to damp the relays' back EMF using a diode. It will cost you little or nothing, and there is no consequences from it, other than wiring the relay coil (with its diode) backwards and blowing the tail lamp circuit fuse.

You have everything to protect, nothing to lose, near zero cost, and no added complexity. Do it. Make sure the diode is mounted securely - preferably soldered securely inside the relay case. Mark pos and neg on the outside of the relay case.

Steve

[dipshit]

It is always good practice to damp the relays' back EMF using a diode.

Ok, that just leaves one question...

Is this 'Zener 1W 12V 1N4742/BZX85C12' diode from dick smith the right one to use for the job?

[hospitalfood]

ok. question for smart people.
at present i run no extra gadgets on the buell, but when i get some demerit points back i will be running my radar detector again.
i basically always run my headlights on high.

can i safely pull more power out of the system for heated grips without melting stuff like regulator/rectifier or whatever ?

not sure how many amps it generates

[dipshit]

can i safely pull more power out of the system for heated grips without melting stuff like regulator/rectifier or whatever ?

I don't know the technical answer to calculate such things, but things like this are reassuring...

http://www.canyonchasers.net/shop/generic/relay.php

"Also, most bikes generate far more electricity than the bike needs; enough to have the ability to run two heated vests and a set of heated grips without putting any undue strain on the electrical system. However, every bike is different and you should check to be sure your bike can handle the added electrical workload. We've yet to find any bike that did not have a strong enough alternator to handle heated grips. On almost all of the CanyonChasers bikes, we run heated grips, up to two heated vests, GPS devices, MP3 players and radar detectors – all at once – and have never had any problems. Mikey has even set up a way to charge camera and phone batteries and has never run into any problems."


And some radar detectors show battery voltage if it starts getting too low. (like if your alternator can't keep up)

[CookMySock]

@dipshit, no don't use a zener. Almost any othjer silicon diode will do. 1N4001 etc. edit: make sure you wire it the correct way around, so it does not conduct when the relay coil is energised. Test with a continuity light tester. If you get it wrong it will just blow the taillight circuit fuse - just swap the diode the other way around, or reverse the terminals on the relay.

@hospitalfood, yes you can. The more load you put on the entire electrical system, the less load there will be on the regulator. The stator is designed to run into a near short-circuit.

Steve

[Hawkeye]

The relay I got was from DS (P8035 - Raylex - 12vDC 30A - $7.99) .

I also purchased a pre wired block (P8036 - $4.68) which fits the connectors making it a much neater assembly. This has a thin red wire on 86, a thin white wire on 85, and much thicker wires (green 87, Black 30 , Blue 87a). Probably to handle the 30A hence the gauge of the wires.

Following the diagram, 86 is the ground and 85 is the 'live' that feeds the relay causing the switch to close the connections between the main power supply of 87 and 30 once 85 goes 'live' ie. turn on the ignition.

The relay has a spade in the centre for 87a. Does this need to be wired anywhere? Or do I just remove the blue wire? None of the explanations mention this connector.

As you can see from #6, the molded block makes it a nice neat setup.

[Coldrider]

Without seeing it is is probably the 'normally closed' contact of the switch.
All you need is the live to feed the coil, earth the other end of the coil, the common (of the switch) and the normally open contact (controlled side of the switch). Or the extra contact maybe a double pole switch. (not sure what the numbers are).

[slofox]

Anybody got a circuit diagram of how the diode would wire in?

Coz I ain't got one in my auxiliary distribution block circuit...so far so good...

[dipshit]

The relay has a spade in the centre for 87a. Does this need to be wired anywhere? Or do I just remove the blue wire? None of the explanations mention this connector.

No need to use 87a. You can lose the blue wire.

[dipshit]

Anybody got a circuit diagram of how the diode would wire in?.

Halfway down on this page...
http://www.ripper1.com/tech/wiring.php

However I'm not going to worry about adding a diode now. The relay i got already looks to have a resistor or diode between 85 and 86 for spike protection. (see pic of the wiring diagram on the relay cover and the resistor or diode beneath the spring running between 85 and 86) Anyways a voltage spike getting into my taillight circuit won't get any further than the off ignition switch. I was more concerned about spiking the ECM or something sensitive like that.

Have a look at page 12 and 13 in this...
http://www.autoshop101.com/forms/hweb2.pdf

[dieseldave]

I don't think a diode is necessary unless it is recommended by the bike manufacturer. Usually fitted when some electronics is controlling the relay but in this case a simple switch so no need. May stop some sparking at the control switch terminals but in that case a capacitor would do the job too. A foil or polystyrene type about 10uF would help in that case.
In case it is a requirement the diode goes between 85 and 86. Firstly test these terminals (85,86) with a meter on Ohms to check that a diode isn't already fitted - sometimes they are. Swop the leads around to find out if the meter deflects only one way. If the same in both directions - no diode.
The diode say a 1N4007 has a white band around one end this would go to the positive (red) lead of the relay, the other end goes to the white lead.
The terminal 87a is the normally closed set and can be ignored. bend the end of the wire over and tape it.
Put the diode in a bit of sleeving to prevent shorting etc.

[CookMySock]

a capacitor would do the job too. A foil or polystyrene type about 10uF would help in that case.

Be careful adding any sort of capacitor to any automotive electrical system. You can induce ALL SORTS of weirdo behaviour by adding such a thing.

Even adding a reverse diode to the coil will extend the release time of the relay considerably, making for strange happenings where timing was an issue. At least a diode behaves sanely compared to a capacitor.

Steve