High Beams

[buzzcut1580]

So my headlights work, and my highbeams just recently worked as i remember using them. However last night, i was driving with my lights on and pushed the arm foward for high beams and Bam.. Total Darkness.

Thoughts on why my highbeams dont work ? Does anyone know where the fuse is i should check for this so i dont waste time pulling them all out individually checking.

 

[yomadmike]

Could be your filaments for high beam in the bulbs.?. I had a friend who's low beams went out in both bulbs. He made everone mad driving at night. lol

 

[buzzcut1580]

Someone please help. I was driving threw the back roads last night and my regular lights just were not cutting it. My bulbs look fine; I took one out and looked at it. And my fuses look fine, although my # 1 was blown, so I inadvertently fixed my cigarette lighter by changing that. Any thoughts are appreciated.

 

[ToplessStang]

It's fuse 38 20amp. If that is good and you say your bulbs are good you have some electrical trouble shooting to do which isn't easy to explain. Could be the multi function switch, a splice ect.

 

[RedDaemon]

you might have to replace the light switch unit. similar things have happened to me and alls i had to do was replace the switch unit. its not too difficult

the part looks similar to this:

 

[buzzcut1580]

that was going to be my next question. In googling this problem, people with other cars say its there dimmer switch.

Where is this switch on the mustang so i can check it out ?

Thank you!

 

[buzzcut1580]

i am guessing its behind the pull knob for the headlights?

 

[buzzcut1580]

well i pulled the switch out but autozone does not have it in stock.
Should be here tomorrow. I hope this works! 21 bucks btw if anyone was wondering.

 

[RedDaemon]

sorry i went to brunch :-/

yeah they arent that expensive. when i pulled mine out of my V6 the connectors were all scorched and the plastic was cracked and easy enough to install...putting the knob back on tho is sometimes a bitch

 

[buzzcut1580]

well thats not what it was. high beams still dont work. =(
Can anyone else help me?

 

[n0v8or]

What model year?
Do they come on when you pull the lever to the "flash-to-pass" position?
Does the Hi Beam indicator lamp in the instrument cluster come on?
Try "jiggling" the dimmer lever to see if there are any quick flashes from the beams (a symptom of a bad simmer switch).
Do you have a voltmeter? If yes, turn on the hi beams and check the voltage at both ends of the hi-beam fuse. Both should be around +12V. The Negative meter probe must be connected to a clean ground point. No voltage at either end usually implicates the dimmer switch.

Common causes for hi-beam failure are the fuse and turn-signal/wipers/dimmer switch, mounted on the steering column under the plastic covers. On some models, the ignition key cylinder mus be removed to remove the covers.

 

[buzzcut1580]

It is on a 2001 mustang GT with fog lights.
Just to re-describe the problem...

If I use my flash to pass, the fog lights go off, the headlights stay on, and the high beams do not come on.

If I just turn the high beams on by pushing the leaver forward, again the fog lights correctly go off, the headlights turn off, and the high beams do not come on, total darkness.

So far, I have checked all fuses. Swapped the fog light relay with the wiper relay to see if that was the problem, checked one headlight bulb, the filaments look fine, and finally changed the headlight dimmer switch.

I guess the next thing is to change the multi function switch? Is that what I should try? I bet that’s a big job being in the steering column? Is the switch a lot of money?

I will have to go over my brothers and have him check the voltages first.

 

[gtss]

So what part did you actually change, because the dimmer switch actually is the part of the multifunction switch
it is quite possible, as mentioned before that the connector at the multifunction switch is melted and heat damaged

when checking your circuits have a look at the connector
also if you have tilt steering try operating the lights with the steering wheel fully tilted up and down sometimes the wires break and by moving the wheel down you can temporarily get contact
hope this helps
gtss

 

[n0v8or]

Excellent summary of the symptoms. It helps to narrow down the possibilities.

In the case of "flash-to-pass", the power flow is in this order:
Battery
30A fuse located in the box next to the battery
Multifunction switch
Fuse located under the instrument panel
Junction point where 4 loads are wired together . . . .
. . . R hi beam lamp
. . . L hi beam lamp
. . . Instrument cluster hi-beam indicator
. . . fog light cutout relay
Ground

The fog light cutout relay works OK, which suggests power is reaching the junction point (wiring splice), and all the fuses, as well as the dimmer switch, are working.

Two quick tests to do:
-1- Check the instrument panel indicator to see if it goes on, both at flash-to-pass and steady high beam positions of the dimmer switch.
-2- Go out and look at the headlights at night, to see if the hi-beams are actually turning on, but are dim.

If test 1 fails (or the indicator is on-but-dim), and you have dim hi-beams, it could still be the dimmer switch at fault. It may pass enough current to operate the fog light cutout relay, but not enough to fully turn on the lights.

If the panel indicator comes on nice and bright, and the hi-beam lamps are both completely dark (not dim), I would try 1 new bulb and see what happens. While it would be highly unusual for both high beam filaments to fail at once, one could have failed a couple of weeks earlier and you just didn't notice.

If a the new bulb still does not work, we are pretty much left with a wiring problem.

 

[buzzcut1580]

oh ok, thanks for the help. Yes i forgot to mention, when i put the highbeams on, or use the flash to pass.. the highbeam light does come on in the dash fully.

I will try a new bulb and see what happens. This will be pretty silly if its just the bulb. haha.

 

[n0v8or]

A dim indicator light means even new bulbs will not get full power. There is no point to trying a new headlamp bulb until you have achieved a full-brightness indicator lamp.

Do you have a voltmeter you can use to check the voltage at fuse 38 under the dash? There are small holes at each end of the fuse for a meter probe to make contact while the fuse is still in place. Fuse 38 is the 4th (of 6), counting from front to back, in the row that is closest to the steering column. It is supposed to be 20A (yellow). Both ends of the fuse should read the identical voltage with the key and hi beam switch both On.

If you read ~12V at the headlight fuse near the battery, but less than 10V at fuse 38, we will know the problem is between those 2 points.

 

[1Phat5Liter]

Do a HID conversion... it's easy and very affordable.

 

[buzzcut1580]

In case anyone was wondering... Turns out its the plug, if i push it in harder to the bulb, the highbeams turn on. Maybe i will try to rig it with tape, lol
Maybe the bulb on the drivers side is just bad, i never took that one out because the battery is in the way.

 

[buzzcut1580]

Well i pushed the plug in real tight, and then had my wife electrical tape it tight, and it is working now. Maybe i will have to get some electrical cleaner.

Still havent had a chance to check out the drivers side since the battery is in the way.

You guys were right, my drivers side must have been out and i didnt notice it, then when the passanger side went out, i thought i all of a sudden had no high beams and a major problem.

Thanks for everyones help!