Wiring Fog Lights - like pullin teeth

[isalwaysright]

On my 81 BJ44 all I want to do is wire in some OEM fog lights like these https://forum.ih8mud.com/showthread.php?t=66617.

Do I run the hella 87426 relay with an off the shelf switch?

Last thing I want is a fire so I'm asking the pros.

 

[Stone]

If you use a switch that is not illuminated, it doesn't care what voltage it switches, although it does have an amerage load limit. You can use the 24V 87426 relay if you're using 24V to switch the relay on and off.

If you're using an illuminated switch, and it's rated for 12V, then you'll have to use 12V through it to avoid burning out the light inside the switch. In this case, you will be using 12V to switch the relay, so use a regular 12V relay. Pin 30 and Pins 87 and 87a on a relay also don't care what voltage they see because that's just the switch portion of the relay...so you can run 12, 24, 36, or 48 volts through that portion and it will be fine...although again there's an amerage load limit. Pins 85 and 86 power the relay's coil...and that's where 12V or 24V becomes critical.

Also don't forget to fuse the wire supplying power to relay pin 30 for your foglights. Good luck.

 

[isalwaysright]

I'm sorry to show my ignorance but this is my first 24volt experience.

Seems I need to reduce the voltage before the relay.

Am I correct and whats the best way to do that?

Much appreciation for your advice!

 

[Stone]

Seems I need to reduce the voltage before the relay.

Hey, no worries...that's what's great about a forum like this...we can all share info and get info on what we need.

If you mean reducing voltage to the relay coil because your truck is 24V and your relay's 12V...then the easiest way to fix that is to use a 24V relay. If you mean reducing the voltage from your 24V battery bank to the supply pin (pin 30) of your relay because the bulbs in your fog lights are 12V, then the easiest way to do that is to change your bulbs to 24V.

If it's the second scenario, then most likely the bulbs in there are H3...and those are available in several wattage in 24V...55W, 70W, 100W, 130W, etc. Remember to consider your tiny little diesel alternator's output when you are adding these types of accessories. When I had my BJ74, I had 24V 70W H3 in IPF MSR900 lights, and because of the high quality reflector and lens, they threw a beam like no other lights I've owned before.

 

[isalwaysright]

Outstanding - once again - Thanks!