Headlights

[Zer0]

I was looking at http://www.midnightdsigns.com/james/headlights.htm
and was wondering something from this list:
Part P/N Price
30-amp Bosch Relay 330-070 $1.99 ea.
40-amp P&B Relay (better than Bosch) 330-074 $2.25 ea.
Relay Socket (single) 330-075 $1.25 ea.
Relay Socket (dual) 330-078 $1.90 ea.
Relay Socket w/diode (use with EFI) 330-076 $1.75 ea.

So do I just need 2 40 amps P&B Relay and a 20 amp fusebreaker besides the wiring for my 64.5 to get some H4's?

 

[rbohm]

I was looking at http://www.midnightdsigns.com/james/headlights.htm
and was wondering something from this list:
Part P/N Price
30-amp Bosch Relay 330-070 $1.99 ea.
40-amp P&B Relay (better than Bosch) 330-074 $2.25 ea.
Relay Socket (single) 330-075 $1.25 ea.
Relay Socket (dual) 330-078 $1.90 ea.
Relay Socket w/diode (use with EFI) 330-076 $1.75 ea.

So do I just need 2 40 amps P&B Relay and a 20 amp fusebreaker besides the wiring for my 64.5 to get some H4's?

you are going to need one relay for each circuit, and that means 4 relays, two low beam and two high beam. you however only need two 20amp circuit breakers, one for each headlight, as you are only using one filament per headlight at a time.

 

[67CoupeDriva]

I don't think you need 4 relays; I did mine with only two. One relay for both lights low beam, one for both lights high beam. Maybe I've missed something, but unless you're doing something tricky that will do it.

 

[rbohm]

I don't think you need 4 relays; I did mine with only two. One relay for both lights low beam, one for both lights high beam. Maybe I've missed something, but unless you're doing something tricky that will do it.

i like to keep the wiring between the relay and the lights as short as possible. but you are right you dont need four relays to make this work.

 

[yeloxr7]

Use SEARCH to find several threads on this subject. You can even get relay harnesses ready to install from some vendors.

 

[66moneypit]

Summit Racing sells the harness for 31 bucks.

 

[67CoupeDriva]

i like to keep the wiring between the relay and the lights as short as possible. but you are right you dont need four relays to make this work.

Any particular reason why? I'd think you would want the longer run of wire to be hot only when the switch was on (relay to light), instead of always hot (batt to relay). Assuming you're using the same size wire there shouldn't be any difference in resistance or anything, right? Just wondering if I've shortchanged myself somewhere.