Headlamps (high and low beam) stopped working why?

Hello, I'm Danny.

It sounds like you might be having an issue with a faulty headlight switch. I've attached picture steps below on how to remove and replace the headlight switch on your truck. Hope this helps and thanks for using 2CarPros.

It is unlikely that this is a fuse issue but we need to check voltage at the multifunction switch to see if the lights are being commanded on. I attached the wiring diagram below for your review.

https://www.2carpros.com/articles/how-to-check-wiring

Also, I suspect this is a switch issue so I suspect we need to replace it and I attached the info below on how to do this.

Please let us know if you have questions on this. Thanks

More than likely this is the multi-function switch. If you look at the wiring diagram, both the hazards and high beams run through the switch. It is odd that only the front hazards don't work but again this is the only thing that makes sense for both of these to not work. I included the test to proved this out because there is always a chance that you have two separate issues. However, I would track this down first or just go ahead and replace it as they are not that expensive.

Couple questions. First does the high beam indicator work as well? If it does then I suspect we have an issue with the multifunction switch. The way this works is when you turn the switch to the low beams, it puts power through on the two circuits that I circled below.

Then when you switch to high beams, the switch actually changes to a different circuit internally and controls the voltage through on the same circuits. So if both low beams are not working then I would replace the switch and go from there.

Here is a video that will help with replacing this:

https://www.youtube.com/watch?v=WxE9ukmE8B4

Let us know if there are questions.

Okay. Then assuming you have the same 1999 Ranger, I am confident that the switch is the issue. Here is that video again on how to replace it:

https://www.youtube.com/watch?v=WxE9ukmE8B4

Let us know how you make out. Thanks

Sounds great. They are a good truck. Let us know if you have other questions and feel free to get a new post of your own started if needed.

Thanks

https://www.2carpros.com/questions/new

Great addition to this thread! Please feel free to help out whenever you are on the site :)

Cheers, Ken

Hello, I'm Danny
It sounds like you might be having an issue with a faulty headlight switch. I've attached picture steps below on how to remove and replace the headlight switch on your Ranger. Hope this helps and thanks for using 2CarPros.

Hi David,

Thank you for the donation.

When light switch is turned on, the Red/Black wire must be HOT, if not the switch is faulty.

If Red/Black is HOT, check fuse # 4 and # 8 ( 10 A fuse in underdash fuse box).

At the headlights if there is voltage to the White/Light Green and Dark Green/Light Green wires, the bulbs are bad.

Fuse 33 is for the high beams.

When wires age, they tend to have higher resistance and this would result in them heating up. Ensure the wires clamped onto the terminals are tight and if the wire is old, you might have to consider replacing it. Ensure the terminals are tigh as well, a loose fitting would cause heat to build up.

One way of overcoming overheating of the headlight circuit and and prolonging the light switch life span is to install a relay and let it handle the high wattage rather than letting the high wattage go pass the light switch and wirings.