Hello folks,

I'm upgrading the headlight harness for my '00 F350 to get beter lighting.

Parts I have:
9007 65/55w bulbs
14ga wire
(2) relays
Fuse block
connectors

I'll be using the stock headlight housing, for now, and eventually I'll upgrade to the 02 - 04 headlight housing.

I want to be able to run the low beams while the high beams are on.

I'm stalled at which diode to get. I've found numerous threads about adding a diode, but, there is no mention of which one. There are different ones available and I don't want to install the wrong one. The diode would be connected between the relays.

Which diode should I use for this application?

Thanks,

 

If you use the diode on the control side of the relays(the side that controls the coils) you can use a very small diode from radio shack. A 1 amp diode should be plenty big enough.

Has anyone who has done this mod on your model truck had any bulb and housing overheating problems? I would not do it for other reasons also, but I won't get into it unless you want to know.

 

Yes...I would be installing it on the control side. I've seen 1, 3, and 5amps available at electronic stores. I wasn't sure on which one to get. 1 amp makes sense, though, as there is no load on the control side. Thank you for clarifying which one.

I hadn't asked the question in the forum pertaining to my model yet. I figured I'd read, read, read, and then start the question in this forum first.

I've read many different threads from different truck forums. I don't recall seeing any reference to my year headlamp housing melting because of the extra heat. I do remember reading some who use the 80/100w bulbs, without the diode, with good results; and, I do recall reading about one who ran the 80/100w bulbs, with the diode, with no complaints. I don't think I will be running 80/100w bulbs though. Not out to be overbearing to oncoming traffic.

Since you made a mention as to why you wouldn't do it, I am curious to know for my knowledge of the subject. Would you mind sharing the reasons?

 

You can try it if you like, but there is some controversy on if it actually impairs your long range vision at night. It's partly the way the eye works and how the lights are designed.

The lowbeams light the road very close to the front of the truck. The highbeams both close and far away. When both are used together you get double the brightness right at the front of the truck. This extra brightness can impair your long range vision. The extra glare at the front can fool your eye and make it less sensitive to the far field of vision.

My wife's Honda does work this way, leaving the lowbeams on all the time, and just adding the highbeams. Maybe this is were the idea came from? But as I was discussing this a long time ago, I was enlightened to the fact that the Honda headlight housings are specifically designed for this, with separate bulbs and reflector housings for the low and high beams. The highbeams on that car light the far field without doubling the light right in front of the car.

 

Ok...I see. After the install, I guess it is something that I would have to try for a little while(with a diode, and, without) and see how the performance of both beams affect my vision at night and the housing from the heat.

Nice that you use a Honda lighting as an example, because this applies for my reference.

The narrow country road just before my house is hilly and no streetlights. My low beams and high beams are terrible on this road. Driving my wife's '05 Accord down this same road, the difference in illuminating not only the road but the whole area is amazingly different. The low beam bulbs and high beam bulbs in the Accord are in their own housing similar to your wife's Honda.

That is why I am pursuing the upgrade. Thank you for sharing your knowledge Dave.

I appreciate it,

 

You can try it if you like, but there is some controversy on if it actually impairs your long range vision at night. It's partly the way the eye works and how the lights are designed.

The lowbeams light the road very close to the front of the truck. The highbeams both close and far away. When both are used together you get double the brightness right at the front of the truck. This extra brightness can impair your long range vision. The extra glare at the front can fool your eye and make it less sensitive to the far field of vision.

I did this same thing on my Tahoe, they call it "all 8 on high", lighting my high beams, low beams, DRL and fog lights. I called it "Retina Burn". In town on the streets I loved it. It really lit the road but that was all close up. We were out in the dark in the Oregon hills and I felt like I couldn't see. I then learned about how the eye focused and it all made sense.