Relay wireing Question

[gotcha79]

i am about to start adding relays to my Headlights and Ac and high speed switch fan what i am trying to figure out before i buy the wrong relays wheres the best place to get them and how can i wire them i see 2 style of relays (5pin or 4pin relays) i am trying to accomplish this
1) How & which relay between relay# 1 or relay# 2 to use for my headlights?
2) How and which relay between 1&2 should i use and ?

 

[gotcha79]

Anyone ](*,)

 

[Ed Cannon]

Just buy the 5 terminal relays. You don't have to use the center terminal (87a). Also you don't need relays for headlights, but it wont hurt to have them either. Bosh makes the best relays.

 

[gbodystuff]

Adding relays to trigger your headlights does indeed help-it reduces voltage drop so they will be a little brighter. More importantly, if you plan to upgrade to HID style bulb conversion, you'll be set. The problem with NOT running a relay is that the power for the stock headlights run through your headlight switch which routes through a ballist resistor which limits current output...so you can imagine what happens when you try to use high output bulbs running through the switch...it gets hot-way hot...so yes, there is no reason in the world NOT to run your headlights off a relay. Adding a relay for your AC will also help reduce voltage drop. This is the overall goal of relays-shorten the distance between the device requiring power and the power source itself....meaning the alternator or a closely sourced power junction-DO NOT run power directly off the battery-this is not an efficient way of directing current demands.

 

[Doober]

Personally I'd go with a set of relays that use weather pack connections, especially if they're going to be living under the hood.
http://www.bmotorsports.com/shop/product_info.php/products_id/503

 

[gbodystuff]

Try to find good quality wire as well-I spool my own harnesses and kits so I use OEM quality Delphi wire spools and connectors but stay away from parts store wiring...they have too much "filler" material that add up to junk wire.

 

[gbodystuff]

Try to find good quality wire as well-I spool my own harnesses and kits so I use OEM quality Delphi wire spools and connectors but stay away from parts store wiring...they have too much "filler" material that add up to junk wire.

 

[slimbo]

you build harnesses and kits and dont know which relay to get or how to wire them? if the correct guage wire is used from the alt to the battery the drop should be under .1 so its fine to run power off the battery for the 30 poles on your relays. headlight power does not go thru a ballast resistor either. you can check the drop coming out of the switch and its likey a .3-.4. part of the preventive maintenance schedule on the ups trucks i maintain is doing voltage drop tests on all priority circuits so i know what faulty wiring and improper guage wiring can do in terms of poor performance.