How to add a relay to starting circut ?

[rdkng]

I added some rear lights, eventually got bad connections, fried my ignition switch.
(1995 'king, 85K 10:1 compression, stroker with stock starter & new ignition switch on order

In previous posts I've read that adding a 4 prong 30 amp relay into the ignition
starting circut is a good idea, but how do I do that ?  What goes to the 4 prongs?

Any info, tips, & 'how tos' would certainly be appreciated.     
Thx
rdkng   

[bigtone]

You may be thinking of the ignition relay that crane used to recommend. It eliminated some of the voltage drop to the ignition circuit. You already have a starter relay. Crane used to have a drawing on their website, but I heard they closed up. S&S bought some of their assets. If you google crane cams, S&S has some info posted, including a link to the start boost relay, but the link didnt work for me/

[attachment removed after 60 days by system]

[hrdtail78]

85 will be ground, 30 will be power (ignition switch power) 86 will be power (starter button) and 87 will hook to the starter.  If you use a relay for a car, it will have a 87A.  Leave unhooked.  Your 95 should have one already.

[FSG]

The the12volt.com is an excellent source for the information you seek and has a section on Relays and their uses.

[fuzznut5197]

You may be thinking of the ignition relay that crane used to recommend. It eliminated some of the voltage drop to the ignition circuit.

Yeah, it was something like this:

[fuzznut5197]

Or maybe like this?

[hrdtail78]

I dont understand what this is suppose to do.  Would it be easier to put on a soliniod pushbutton for backup?

[fuzznut5197]

I dont understand what this is suppose to do.  Would it be easier to put on a soliniod pushbutton for backup?

This explains it pretty good...


http://www.daytona-twintec.com/download/Ignition_Relay_Instructions.pdf

[96FLSTF]

What Fuzznut sayz 
I did this relay mod on my 96 fatboy long time ago and it eliminated kickback I had. It improves the volyage to the coil when you press the starter button. When you press the starter button the starter is pulling most of the current. This mod allows the coil to get juice needed almost directly from the battery instead of wiring that is run up to dash, bars run button, switch, etc.. Yes it really works.

Copied & pasted from Crane's explaination:

Difficulty in starting is a common problem on many Harley-Davidson® motorcycles. In some cases this is due to a weak or undersized battery or a problem with the wiring on the bike. In other cases it is due to a high-compression, big-inch engine which causes the starter motor to labor during cranking. Under these conditions, the voltage available to the ignition system may fall to as low as 5 volts as the engine comes up on compression. This voltage drop can reduce the spark energy to a level insufficient for firing the engine.
In single fire applications where the voltage at the coil drops during cranking, adding a coil-feed relay can improve starting performance. This relay applies full battery voltage to the ignition (module and coil) and eliminates the 1-2 volt drop in the H-D OE wiring.
Crane Cams recommends a high-quality automotive relay such as a NAPA AR274 or a Radio Shack 275-226 with a minimum 10-amp rating. The terminal numbers shown below are standard for most automotive relays.


Disconnect the white ignition switch wire from the Coil + terminal and connect it to the relay #86 terminal. The terminal numbers are usually marked on the bottom of the relay, next to the metal terminals. Then wire up the rest of the circuit as shown below. Use 16 AWG (16 gauge), automotive rated stranded wire. Connect the wires to the relay using ¼" female push-on crimp terminals. Take care to properly crimp the terminals to the wire.
Gene

[rdkng]

Thank you all very much for your time & expertise !  Great info.

'course yall are correct, my 1995 already has starter relays.
I also have a Hi4E, so the 'coil' relay souds like a good idea.

What kicked off my thinking was the mechanic that was helping me get back on
the road (by successfully installing a toggle switch to bypass my burned ignition switch)
made the comment that he frequently installs a relay that somehow seperates ? the
lights.  He says that helps the folks that add lights or go to higher draw ones.

Anyone know how that would be hooked up ? 
Thanks
rdkng 
       

[FSG]

..........that he frequently installs a relay that somehow seperates ? the
lights.  He says that helps the folks that add lights or go to higher draw ones.

Anyone know how that would be hooked up ? 
     

I would be done in a similar manner to the Crane Boost Relay.  Have the Ignition Switch/ Light Switch control (turn on/off) a relay and have the relay switch fused power directly from the battery to the lights.

[FXRick]

I've added to my '92 FXR a relay to turn the lights off during starting. It has a connection between ignition and lights fuses that was removed and replaced by the prongs 30 and 87a ( normally closed positon ). Using the signal from the starter relay and ground for the 85 and 86 prongs, it opens the lights circuit while the start button is pressed, avoiding another drop in the voltage. I hope it helps, if it can be understood. Rick

[FXRick]

Hi,I`m sorry, forgot to mention that the relay must be the "Normally closed type" for the 87a prong, in the other types the 87a is just the same as 87, for an indication light or so. It is printed in the case.Rick.

[rdkng]

Thanks FSG, FXRick and guys. for the info..  yall do some clever things !
(once I get my current wiring headache solved, I can get back to 'improving' things
rdkng