I have a 1965 Ford F-250 and only the high beams work. I was wondering if any of y'all had any ideas why this keeps on happening. high beams on high beams off
Are the low beams burnt out? Switch or jumper the high beam onto the low beam terminal on the headlight. Or pull out and test on a good battery with two jumper wires.
As mentioned ! it's not unusual for both to burn out at the same time, high or low beam If low beam works with a jumper at headlight , then look for issue between foot dimmer to headlight's more likely on the positive power side. And good grounds just as important
My vote dimmer switch, had this exact thing happen to me years ago as I was driving down a hiway late one night, people were p*ssed because I wouldn't kill my brights... ...
I see that you’re 16 years old. This is some of the simplest troubleshooting there is. Get a 12v test light. Turn on the headlights. Unplug the wires to the dimmer switch. Use your test light to determine which of the three wires has power. Now plug it back in and with the high beams on probe the other two wires and see which is hot. Now cycle the dimmer switch to low and the third wire should be hot. If it isn’t then the switch is bad. If there is power then the problem lies between there and the headlights
My 1957 F-100 dimmer is intermittent and sometimes doesn't work at either hi or low beam. Switch is exposed to road dirt and doesn't help.
Long ago,I had a werid prob. with a set of head lights like your talking about. After a few days of checking n rechecking,moving bulbs around;;;; It was,one of the 2 sealbeam bulbs had burn a high filament=one end had burned off,an the broken end filament had then welded it's self too the low beam= So there no longer was a high n low-just one beam,no matter what switch was on or off .... None of that showed up tell, I had taken one of the two headlight sealbeams out of car n left one in.
Had that happen once to an OT car. I turned on the headlights, and they both went out simultaneously. Both bulbs burnt out at the same time.
If it is the switch (floor mounted?) any good parts store should have one. Standard Ignition part #DS70. Shouldn't be too much $$. Glad to see a young guy like you here on the HAMB!
Simple troubleshooting. With a test light or a voltmeter (my preference), go to the back of the headlight where the connector it. Leave everything connected. There are three wires, one is power for the low beams, one is power for the high beams, and the other is ground. Turn on the low beams. Back probe each wire of the connector with your test light. One of the terminals should light the test light. If it does, your foot switch is okay and the most likely cause of no low beams is a burned out bulb. If none of the wires light the test light, you need to do a similar test at the foot switch connector. Some may say the problem could be your ground. However, the low and high beams share the same ground. If the high beams work, you do not have a ground problem. If none of the wires on the headlight would light a test light, you need to check the foot switch with the connector still connected. The connector there will also have three wires, power from the headlight switch, power to the low beams and power to the high beams. On low beams you should find power (light a test light) at two of the wires, power from the headlight switch and power to the low beams. If you don't, the foot switch is bad. You can try cycling the switch a few times and you might get it to work, but it needs to be replaced.
It's good to start out with wiring diagrams so they make sense right off the bat. Think of the storm water system in your town. A map will make it make sense, even if you can't see it all. Here's the lights.You can click on the picture to expand it, or save the picture for reference. The headlights are at the left side with Black, Red and Green wires. You have a ground circuit at the bulbs, that is the Black wire (38) shown. This is proven to work because without it, no lights. That connection to ground at the bottom left often causes issues and should be cleaned and tight, but not to worry for now. For the low and high beams, you have Green (12) and Red (13). If you trace the Green (12) circuit, it goes back thru the connector to the Dimmer Switch and to the high beam indicator. So Green is the High Beam, Red is Low Beam. The Green (12) circuit is working because the high beams work. This partially proves out the main disconnect and the dimmer switch, and the Red/Yellow (15) wire from the light switch is supplying power when the headlight switch is used. So it's either the dimmer swtich as mentioned, both bulbs as mentioned or an open Red (13) circuit (broken wire or bad connection) on the Red (13) wire between the dimmer switch, thru the connector and to the headlights.
If the OP's lights were stuck on low beam I would disagree, but the dimmer always fails when on high beams. Time for a dimmer switch I think.
Had a friend who drove old cars and never spent any money keeping them up. He came to the dealership one day because he got at ticket for driving without headlights. Both his low beams were out. Of course he wanted free advice. I told him to go to the junk yard (the dealership had it's own mostly Mopar yard) and get two headlights out of an old car and I'd only charge him a dollar a piece. But, let me test them before you install them. He said how could you know that both my headlight were burned out? You haven't looked at anything. I told him I just know things. Actually I had seen him driving for about a month or two with only one headlight. I was pretty sure the other one had finally burned out.
Dimmer switches can fail on either the high beam, or the low beam. If your dimmer switches are always failing on the high beam, you may want to check the condition of your headlight grounds. The high beams are trying to ground more voltage, if that is what keeps failing, I would suspect a poor ground with too much resistance. For those of you guys still running the old Fords that have the dimmer switch with the wiring sticking out through the firewall, it may be worth while to convert to the 60s style dimmers that have the wiring inside of the car. Its the same function, the wire pigtails for the inside dimmer are available, the dimmer itself is cheaper, and its much better for the wiring to be inside instead of out in the weather.
To test, using the info I posted. Grab a test light. Ground the wire to battery negative. Touch the pointy bit to the Battery positive to confirm test light works. Next, turn on headlights and touch pointy on the Green lead at the back of the headlights. I should turn on just like the battery touch. Next, kick the dimmer switch and check the Red connector at the headlight. If it comes on, replace bulbs. H6024. If not see if you can touch the red wire out of the dimmer switch. If the ground lead is too short, try it under the dash, connecting test light ground to some bare metal nearby. BUT check that it works on High on the green wire. Then check with it on Low on the Red wire. If it doesn't work right at the dimmer switch, it's the switch. It it lights up, it's the open circuit described.
What I found out was that the terminal was dirty and I needed to clean it out. Now both high beams and low beams work
I ***ume the terminal was at the dimmer? Typical since it is on the floor near your feet. You might want to check that ground connection and the headlight switch terminals too. They were dealing with extra current from the dirty resistance before it all went dark.
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