97 and 98 have no headlight relays. 10A flows through the headlight switch and multifuncting switch. One of the reasons why 97 and 98 have more headlight problems than the rest. I would like to add relays and searched various F150 online forums. Apparently someone did this and posted photos but the photos are gone by now.

Where/How do you mod-experts suggest to install relays? Any suggestions would be welcome. Thanks.

 

You'll need 20A relays intended for use under the hood. You'll probably want to run separate circuits and relays for the RH and LH low beams then a third for the high beams. You will be cutting into the headlight wiring so that the relays switch power to the headlights and the headlight switch just powers the relays. I would use 12ga wire fused for 20A from the battery to power the headlights.

 

Nope.
My 2003 the headlights go thru the switch as well, up to 20 amps.
The relay is only for autolamps to turn on the lights.
The switch is plenty robust, and cheap.
Not sure why you think its a weak link.

My switch hasnt failed
My relay on the other hand........has

 

mbb,
I was misinformed. My apology. Mine failed. The headlight switch is sturdy mechanically, but the copper contacts got oxidized. I want to prevent the same oxidation on multifunction switch. I may be overdoing this. I just have extra relays on the shelf. Also relays are cheap, switches are not.

Feathermerchant,
Thanks. Will do as you advised. Where would you mount the 3 relays? Velcro?

 

If you go with 3 relays, you can mount the low beam relays near each light and the high near the battery. Or you could mount all three near the battery because they will all have a battery connection. Just mount them with the terminals facing down to keep water out. Also at a relatively high location and away from splashes. Usually near the battery is a good dry location.

 

Thanks. Will report back when done with photos.

 

This just my 2 cents, so dont yell at me lol

Adding relays to this system that wasn't intended to have them, is adding an extra part to fail to the system. A relay is used to introduce a new system of power into an existing power system to make the end object do a different task.

Adding a relay in between the main power source to the headlights is like adding a splicer on a cable line only to use it on one tv. lol You are leaving the system to be vulnerable to 3 new relays or parts to go bad rather than one.

The copper inside your switch went bad and became corroded because of age and moisture. I would replace it with a re manufactured or newer one. replacement switches at our parts department were made recently and will provide many years of service.

Again just my opinion. lol

 

Also, if you need just the switch itself, it's only about $20.00

 

You are correct about the reliability Mr Gravy. The switch may just be old or may have a genuine problem. The switch on my 95 Ram was replaced in a recall because it wasn't Beefy enough. I suggest 3 relays so in the event of a failure you will still have one low beam. I think the truck circuits are fused the same way. Three fuses.
Relays on this will give you brighter lights due to less voltage drop.

 

This is what I need:

I see your point. 3 more relays and 3 more wiring sets that may fail. But they are not ADDITIONAL failure points. I am just moving potential failure points from original (multifunction switch + headlight switch + switch wiring) to (3 relays + relay wiring).

For anyone adding headlight relays, I suggest sealed ones from Digikey or ebay, not the cheap ones from amazon.