I have a 1999 Ram 2500 4x4 5.9L that is having headlight problems. Both the high and low beams seemed to be weak, so I purchased new, higher performance bulbs that the sales person said would shine brighter. After installing them, the problem got worse. Now, the low beams are essentially useless and the high beams shine like low beams. In addition, the high beam indicator light now remains on when the lights are on regardless of whether I have low or high beams on. I had a mechanic look at it and he performed a voltage test that showed 12v. He simply shrugged his shoulders and didn't give me any more assistance. Needless to say, I won't be going back there. In the spirit of shade-tree mechanics everywhere, I am now determined to fix it myself. So far, I've read that it could be a grounding issue since power is getting to the bulb and would require using an ohmmeter to test. How would this be done? FYI, there are no DRLs. I have figured out that the original bulbs were model 9004 and the new ones are 9007, but the parts guide at the parts store lists 9007s as an option for this truck. Can anyone suggest a trouble-shooting protocol that I can use to find the problem? Is it possible that the multi-function switch is malfunctioning? The intermittent wipers are also problematic as they only move at the fastest speed regardless of what speed I have them set on. Thanks in advance for any assistance.Lugnutlauf

 

Welcome to the forum!

9007s were an option ONLY if you have the Sport model. 1999-2001 Sport models had 9007s for low beams (outer set of bulbs) and 9004s for high beams (inner set, closest to grille).

9007s will not work in 9004 harness as there are a couple wires switched around.


Only way to make 9007s work would be with some rewiring. If you have a non-Sport model (one set of bulbs), they are 9004s.

Five things I'd do, moving down the list until one of them fixes the issue...
1. Install only 9004 bulbs if non-sport, otherwise make sure 9004s are in the inner holes and 9007s are in the outer holes. They shouldn't be reversible, as they are tabbed differently to prevent that sort of thing.
2. Check battery terminals and ground locations, make sure electricity is moving through where its supposed to. Sounds like you may have already confirmed this a bit with that bad mechanic, but I'd check anyway. Also check the wiring harnesses themselves, make sure nothings melted.
3. Test battery and alternator (free at Advanced Auto and many other auto stores)
4. Replace dimmer switch
5. Replace headlight switch

For information on how to replace the dimmer or headlight switches, download the service manual here. Its for the 2001 model year, but 2001 and 1999 are very similar.

 

yeah, theres different ground locations under the hood, not sure which are for the lights, but they are all easy to spot and check

 

The 9007s are the right ones as long as you own RAM sport with quad headlight. Thats why it is an option for the truck.
The 9007 and 9004 bulbs differ in the pinout. The 9007 has the middle pin as common for the dual filament. The 9004 has middle pin for low beam.
So you still need a 9004.

 

you also need to pay attention to color temperature. 4000k is the whitest and brightest. normal halogens are something like 2000k (yellowish tint) and a lot of the "pretty tint" bulbs are 6000k and up, 8500k is blue, 12000k is purple and i think the green is a higher number, but the further you get from 4000k the dimmer the bulb will be. i got a set of 8500k bulbs for the blue tint but they weren't near bright enough so i got a set of hella bulbs that are 4000k and they're pretty bright and white. also, headlights dim over time, they don't work 100% till they burn out, they slowly die unless you have moisture in the lense, then they just pop. the hella, nighthawk, and sylvania silverstar ultras are the brightest bulbs i've seen so far. the silverstars are said to be the brightest but they seem about the same as my hellas.

 

Déjà vu...

 

check the bulb and the wiring also the alternator....

 

I'll bet your headlight lenses are just yellowed/oxidized from age. Return the 9007's, then get the 9004's of your choice and a headlight restore kit. The one I used comes in a silver foil packet and works great. I don't remember the brand name, but it was the only one packaged in a silver foil packet, so it should be easy to spot. I got mine at Advance.

 

my sister used the one from advance and it made hers look like brand new.

 

Im still to slow in writing.
And i didnt wanted to edit my post.