Dim headlights

So I've been having problems for a long time with my head lights being to dim to really run at night. Wether I use high or lowbeams. They are just visible enough for me to be seen but I couldn't see anything with them. I bought new H4 aftermarket headlights and figured that would fix it. Nope I tested them tonight and they as well were too dim. I figure it's something to do with them being wired poorly. Any suggestions? Any helps guys! Thanks.

 

floor mounted dimmer switch . bad connections , or bad ground at headlights

 

Some folks have good results by wiring in a relay near the headlights. This provides a heavy gauge wire to feed the lights directly, with only minor current needed through the longer path via the switches.
Less resistance loss = brighter lights.

BUT - on the other hand, the stock wiring is generally adequate. You should first check all connectors and wires for corrosion or poor contact, etc. Including the ground.

This assumes your charging system and battery are providing full voltage, cables are tight and clean, well grounded, etc. Check voltage (at the battery) when the lights are off, and then on.

 

Do you have a blower motor in your Jeep? If so, turn on the lights and then turn on the blower motor and see if things get worse. If so, either your regulator or alternator (generator) is most likely the issue.

To check the wiring, unplug one of your light sockets and use an ohmmeter or a multimeter on the ohms function to see which side is grounded. This should be a fraction of an ohm. If it is not, then you have a grounding issue. If it reads good, measure the DC voltage to ground from the other sides of the plug. There are three connections to the socket. High beam, low beam and ground. Measure these and see what your voltage reads. You will need to change your dimmer switch to get both readings, first one and then the other. Depending on the type of headlights you have, you may see voltage on both of the "hot" sides (not ground) on high beam. Then put the socket part way on the light prongs so you can still get a meter probe onto the metal part of the prong on the headlight and measure the voltage. If it has dropped, then you either have a wiring problem or a charging problem. Check the voltage at the battery with the lights on and off and see if the readings are similar. You should be reading 13.8 - 14.2 volts on a good system. If not, then you have a regulator or charging issue.

 

Alright so to add a bit more info it had pretty much no wires in it when I bought it so it isn't the stock wiring. I had to use speaker wire for the headlights because that was what was on Han at the time. As for the switch I'm thinking it may be the probl because it's the original one from 1966

 

The lights get extremely hot! But I figured it may just be the type of lights. The "speaker wire" isn't ordinary speaker wire its the kind for sub woofers. Clearly I'm not very good with giving all of the info! Sorry guys I really appreciate the help!

 

" I had to use speaker wire for the headlights"
"The lights get extremely hot!"


Yeah, but how do they sound??? R)R)R)

 

Oooh no nothing is getting hot. I think it's the ground for the headlights. I wired it to the actual battery and it got no brighter.

 

Ditto -- bigger wire = less resistance = more juice = brighter lights. When people upgrade headlights to higher output bulbs, they often fail to us a heavier harness.

Also agree on the relay to switch a heavier wire on a short run from the battery - simple to rig and reliable.

 

Yes! I replaced the entire wiring for the lights. It still hasn't gotten any brighter

 

The lights are wired "in parallel", right? ( Not "in series." )

 

If you plan on going the relay route, then you probably can get by with the speaker wire from the dimmer switch to the relays. And go with 4 relays, two for high and two for low beams. The speaker wire connections just need to trip the relays and hold them in contact. Then run the heavier wire from the positive side of the battery to the relays then to the head lights and then back to the negative side of the battery.

On this subject how heavy are the wires going to and from the alternator/generator and regulator and the rest of the system?

 

I've done everything I could think of. The alternator wire is 0 gauge I believe. I think I will have to do relays but I have no clue how to do them.