zmilin
Street Tracker
I wrote this up for Bonnevileamerica.com but figured some of you folks may like the info to be available on here.
Above is a schematic and pin out for a SPDT (Single Pole Double Throw) relay. Also known as a Bosh relay.
I like to use these for higher current loads such as driving lights or heated accessories. You can find these in both 70amp and 30amp. The 30amp is more than adequate for anything you will be doing on the bike.
I also like to purchase these with the socket/harness to make wiring easier.
Some basics about these relays (referencing the schematic drawing):
SPDT Relay (Single Pole Double Throw Relay) an electromagnetic switch, consist of a coil (terminals 85 & 86), 1 common terminal (30), 1 normally closed terminal (87a), and one normally open terminal (87).
When the coil of an SPDT relay is at rest (not energized), the common terminal (30) and the normally closed terminal (87a) have continuity. When the coil is energized, the common terminal (30) and the normally open terminal (87) have continuity.
How to get them wired up...
1. I like to prep my relay harness first.
• If I’m using a socket I remove the wire from the 87A position. Usually a strong tug on the wire is all you need to pull it out completely.
• If I’m making my own harness then I just move on to step 2.
2. Next I like to find where my relay will be located and do a temporary mount (tape or zip tie). This way I can route all my wires as needed and make sure none are too short or have tension or worse yet, will be located in a location where they can be pinched or cut.
3. Now I start wiring….
How to wire a 30amp SPDT relay for high current draw accessories with key on activation:
• 85 will go to ground.
• 86 will go to a wire that activates when the key is in the on position.
• 87 will go to my accessory
• 30 will go to my battery + terminal. I add an inline fuse* at this wire (NO EXCEPTIONS) in a location that will be easy to reach if needed.
* NEVER use a fuse larger than recommended for the accessory.
How to wire a 30amp SPDT relay for high current accessories with a toggle switch for activation:
• 85 will go to my toggle switch. The other end of the toggle switch will go to ground.
• 86 will be connected to 30.
o I usually tap 86 to 30 a couple inches down the wire, solder and tape for a clean harness.
• 87 will go to my accessory
• 30 will go to my battery + terminal. I add an inline fuse* at this wire (NO EXCEPTIONS) in a location that will be easy to reach if needed.
* NEVER use a fuse larger than recommended for the accessory.
How to wire a 30amp SPDT relay to interrupt the OEM accessory outlet so it is only on when the key is on:
• 85 will go to ground.
• 86 will go to a wire that activates when the key is in the on position.
• Cut the positive wire leading to the accessory port. Connect one end of the cut wire to 87 and the other to 30. [/quote]
Above is a schematic and pin out for a SPDT (Single Pole Double Throw) relay. Also known as a Bosh relay.
I like to use these for higher current loads such as driving lights or heated accessories. You can find these in both 70amp and 30amp. The 30amp is more than adequate for anything you will be doing on the bike.
I also like to purchase these with the socket/harness to make wiring easier.
Some basics about these relays (referencing the schematic drawing):
SPDT Relay (Single Pole Double Throw Relay) an electromagnetic switch, consist of a coil (terminals 85 & 86), 1 common terminal (30), 1 normally closed terminal (87a), and one normally open terminal (87).
When the coil of an SPDT relay is at rest (not energized), the common terminal (30) and the normally closed terminal (87a) have continuity. When the coil is energized, the common terminal (30) and the normally open terminal (87) have continuity.
How to get them wired up...
1. I like to prep my relay harness first.
• If I’m using a socket I remove the wire from the 87A position. Usually a strong tug on the wire is all you need to pull it out completely.
• If I’m making my own harness then I just move on to step 2.
2. Next I like to find where my relay will be located and do a temporary mount (tape or zip tie). This way I can route all my wires as needed and make sure none are too short or have tension or worse yet, will be located in a location where they can be pinched or cut.
3. Now I start wiring….
How to wire a 30amp SPDT relay for high current draw accessories with key on activation:
• 85 will go to ground.
• 86 will go to a wire that activates when the key is in the on position.
• 87 will go to my accessory
• 30 will go to my battery + terminal. I add an inline fuse* at this wire (NO EXCEPTIONS) in a location that will be easy to reach if needed.
* NEVER use a fuse larger than recommended for the accessory.
How to wire a 30amp SPDT relay for high current accessories with a toggle switch for activation:
• 85 will go to my toggle switch. The other end of the toggle switch will go to ground.
• 86 will be connected to 30.
o I usually tap 86 to 30 a couple inches down the wire, solder and tape for a clean harness.
• 87 will go to my accessory
• 30 will go to my battery + terminal. I add an inline fuse* at this wire (NO EXCEPTIONS) in a location that will be easy to reach if needed.
* NEVER use a fuse larger than recommended for the accessory.
How to wire a 30amp SPDT relay to interrupt the OEM accessory outlet so it is only on when the key is on:
• 85 will go to ground.
• 86 will go to a wire that activates when the key is in the on position.
• Cut the positive wire leading to the accessory port. Connect one end of the cut wire to 87 and the other to 30. [/quote]