Beast o Bodmin
Banned
dont forget gaffer tape and a hammer.
As with all electrical devices in your vehicle the wiring is of utmost importance. Because this is so important with driving lights, lets calculate the power required to correctly power a pair of 100W driving lights.
Power Requirement Calculation
Assume the battery delivers 12V even though a car with the engine running will deliver about 13 -13.8V (dependant on battery condition).
2 x 100W gives us a total power requirement of 200W at 12V
Remember your physics and electronics - P = VI (Power = Volts * Current) or to calculate current I = P/V
The current required to power the globes is 200/12 = 16.66Amps or 8.33Amps per globe.
Add a some losses for the cable, relays and connectors and you will easily need 20Amps
Lights must be wired using at least 20Amp cable or a high quality wiring kit. Have a look at any cable you buy and note how thick the cable is and whether it is multi strand or single conductor. Always use a multi strand cable in your vehicle wiring.
You must use a relay when wiring your driving lights. You do not want to be running a 20Amps feed through the firewall. Also you should wire the relay to come on via the use of the vehicle's high beam.
The relay should be rated at better than the required current i.e. greater than 20 Amps. It is not that uncommon to install a 70Amp relay. The better the relay the less current and voltage drop through it. Remember voltage drop is your worst enemy.
You should install a fuse on the main feed from the battery before the relay. See diagram below.
Keep the wiring neat and away from moving parts. You should encase your wiring in some form of corrugated split sleeve tubing (available from most accessory parts stores). 13mm and 10mm are quite commonly used.
Power Requirement Calculation
Assume the battery delivers 12V even though a car with the engine running will deliver about 13 -13.8V (dependant on battery condition).
2 x 100W gives us a total power requirement of 200W at 12V
Remember your physics and electronics - P = VI (Power = Volts * Current) or to calculate current I = P/V
The current required to power the globes is 200/12 = 16.66Amps or 8.33Amps per globe.
Add a some losses for the cable, relays and connectors and you will easily need 20Amps
Lights must be wired using at least 20Amp cable or a high quality wiring kit. Have a look at any cable you buy and note how thick the cable is and whether it is multi strand or single conductor. Always use a multi strand cable in your vehicle wiring.
You must use a relay when wiring your driving lights. You do not want to be running a 20Amps feed through the firewall. Also you should wire the relay to come on via the use of the vehicle's high beam.
The relay should be rated at better than the required current i.e. greater than 20 Amps. It is not that uncommon to install a 70Amp relay. The better the relay the less current and voltage drop through it. Remember voltage drop is your worst enemy.
You should install a fuse on the main feed from the battery before the relay. See diagram below.
Keep the wiring neat and away from moving parts. You should encase your wiring in some form of corrugated split sleeve tubing (available from most accessory parts stores). 13mm and 10mm are quite commonly used.
Last edited:
freebiker
Well-Known Member
Has no one noticed yet that this post is in completely the wrong place?
But anywhoo, if the above post hasn't confuzzled you enough already, just look for a diagram. It's really easy on any car (my freeby didn't take long for me to do at all).
Depending on how you've bought them, you shouldn't need to worry about all the volts amps and figures as a kit would contain all the correct stuff anyway.
Just look for a diagram and you're away.
But anywhoo, if the above post hasn't confuzzled you enough already, just look for a diagram. It's really easy on any car (my freeby didn't take long for me to do at all).
Depending on how you've bought them, you shouldn't need to worry about all the volts amps and figures as a kit would contain all the correct stuff anyway.
Just look for a diagram and you're away.
This is where the little blighter got to, yes it is in wrong place and hope administrater removes it soon, but till they do here is again with diagram this time. Sorry All.Power Requirement Calculation
Assume the battery delivers 12V even though a car with the engine running will deliver about 13 -13.8V (dependant on battery condition).
2 x 100W gives us a total power requirement of 200W at 12V
Remember your physics and electronics - P = VI (Power = Volts * Current) or to calculate current I = P/V
The current required to power the globes is 200/12 = 16.66Amps or 8.33Amps per globe.
Add a some losses for the cable, relays and connectors and you will easily need 20Amps
- Lights must be wired using at least 20Amp cable or a high quality wiring kit. Have a look at any cable you buy and note how thick the cable is and whether it is multi strand or single conductor. Always use a multi strand cable in your vehicle wiring.
You must use a relay when wiring your driving lights. You do not want to be running a 20Amps feed through the firewall. Also you should wire the relay to come on via the use of the vehicle's high beam.
The relay should be rated at better than the required current i.e. greater than 20 Amps. It is not that uncommon to install a 70Amp relay. The better the relay the less current and voltage drop through it. Remember voltage drop is your worst enemy. - You should install a fuse on the main feed from the battery before the relay. See diagram below.
- Keep the wiring neat and away from moving parts. You should encase your wiring in some form of corrugated split sleeve tubing (available from most accessory parts stores). 13mm and 10mm are quite commonly used.
