The Stovebolt Site Forums The Shop Area The Electrical Bay Headlights Only Work on High Beam

My terminal block and lamp sockets arrived from Classic yesterday. I'm in the process of running the new 12 ga wires.

When I go to test it prior to permanently affixing the crimped terminals, is it necessary to have both Hi and Lo beam wiring in place? In other words if I wire the Lo beams first, can I test the Lo beams with the light switch before wiring the Hi beams or does all the wiring for Hi and Lo need to be in place first?

If you trust you understand how it all goes together. Wire it permanently. No need to test

If not, wire close to permanent with twisting wires together for a test. (leave wires long so as to cut back and crimp)

Yes it's pretty simple. I still like to do all the connections with wire nuts first just to make sure it works. I'm using different colored wires for Hi, Lo and Ground just to make sure I don't accidentally cross things up.

Do both Hi and Lo have to be wired in before testing? In other words will Lo beam work if the Hi beam wiring is not installed and vice versa?

Once you get voltage to the terminal strip near the headlights, you an use one wire to test both circuits. Just touch a hot wire to the connector for both light circuits one at a time, and hi and lo beams should work. Once you've established the circuit to the lights is complete, then you can wire the other circuit permanently. Be sure the hi beam indicator on the dash functions correctly, when the sealed beams are actually running in the bright mode.
Jerry

Now that you are using the terminal blocks, you won't have any wire nut or twisting wires to do. You don't need to do a wire nut test.

Take the negative battery cable off battery!!!!

1. Terminate a wire to each dimmer switch terminal. (use crimp-on ring tongue terminals) Not talking about the center dimmer terminal, that should already have the switched hot headlight wire on it.
2. Terminate the other end to the terminal block, separate screws (use crimp-on ring tongue terminals)
3. Terminate two wires to each terminal block screw used in no. 2. (use crimp-on ring tongue terminals)
These two wires from each screw are left and right Lo beam from one screw and left and right Hi bean from the other screw. Their ends get butt spliced with crimp-on butt splices to the bulb connector pigtail. Same bulb contact for each set as we have discussed.
Crimp and screw it all together permanently, reconnect battery cable and test.

Jerry and I posted exactly the same time.

Yes, the high beam indicator on the dash worked before when only the Hi beams came on.

Bartamos, Are you saying that the left and right Hi and Lo beam wires from each lamp should not be joined together prior to connecting to the termional block?

In other words, each screw on the treminal block will have three wires coming from it - Left Hi, Right Hi, and Dimmer and Left Lo, Right Lo, and Dimmer?

In other words, each screw on the treminal block will have three wires coming from it - Left, Right, and Dimmer?

YES

Ok, that was going to be my first choice but the screw supplied with the block is not long enough to hold a stack of three connectors. I'll have to rustle up some longer screws.

Thanks.

Maybe you can but the two left/right wires on one ring tongue.

Yes, that would make more sense than splicing them down the line somewhere.

I'll have to see what will fit where.

Put two wires into one crimp on ring tongue. If you get longer screws they may short out on the fender.
I should have told you to buy a really good terminal block instead of those Mickey Mouse originals.

Click

Nobody answered your question Otto, so I'll take a stab at it.

Thanks Bill.

Also, I know the center terminal on the dimmer switch is the power terminal from the dash switch.

Which of the other two are Hi Beam and Lo Beam. I assume it makes a difference in order to assure that the dimmer light on the dash comes on when the high beams are on.

I believe the high beam indicator on the dash is wired downstream of the dimmer (high/low) switch, so it doesn't matter which of the two outer terminals are Hi or Low beam.

Follow the wire from the Hi beam indicator and see where it goes. If you removed it during tearing out old wires, just tape and let it hang for now. Once you get it all wired, you will know which terminal (screw) on the dimmer is Hi. So attach the indicator wire to that dimmer screw using a crimp-on ring tongue terminal.

Bill,
At 1:15 today I told him he does not need to test prior to full install. So the question was answered because no pretest necessary.
Otto has this down. It has all been covered. He understands the circuits, he has new wire, he gas new components and the nature of the wiring allows for easy change in case......... It's time to get it done, too simple to waste time testing. Wire it and turn it on.

6 pages is enough

Might I suggest Black for your ground wire. It's a bit of a universal thing.

OK, this is extremely frustrating.

Finished the wiring and now neither Hi nor Lo beams work. Ice pick test light (that works, I tested it) doesn't light up on any of the 6 lamp socket terminals.

It doesn't light up on the three terminals of the dimmer switch either. Also , the dash light Hi beam indicator does not now come on as it did during the initial testing to isolate the problems.

As you recall, we verified that I was getting current to the headlights because the Hi beams worked and the the ice pick lit up in some of the sockets.

I know you guys don't know me from Adam's house cat but I assure you that I am extremely meticulous in everything I do. That's why I ask so many questions about everything and then think about the task at hand before doing it.

I used three different colors of wire for Hi Lo and Ground in order not to accidentally mix things up.

I labeled each one as well with tape H, L and G.

I also put tape with H,L, G on the three pigtails of the new sockets from Classic so there would be absolutely no chance of getting them mixed up.

What the heck happened? The taillights and parking lights come on when the switch is pulled halfway and all the way

Hi from left and right are on a single ring terminal connected to the new terminal block which in turn is also connected to a new wire to one of the end terminals on the dimmer swtch.

Left and right Lo is done the same way to the other outer dimmer switch terminal.

Both sockets are grounded individually to the inner fender. I even put a jumper cable on the negative battery post and connected it to the body just to make sure the problem wasn't a bad ground.

OK, lets check it out. One at a time. Don't jump around. Don't jump ahead. Just answer.... and wait for next step.

1. Is there 12V at center dimmer terminal when headlight switch is pull all the way out?

It;s a 6v system but the ice pick didn't light up when I touched it in all positions.

Further testing is going to have to wait until tomorrow evening after I get home from work.

OK sorry, 6V. all positions of what? Try to be careful with words and be specific at this point.

I pulled the light switch out and tested hi and lo on all 3 dimmer terminals

SO...........the answer is there is NO 6V power to center dimmer terminal when headlight switch is pulled all the way out. Right? Just answer the questions don't give all kinds of other info.

That, of course, means the headlight switch is not sending power to the dimmer.

If you want to test your work before investigating that problem. Take off the center dimmer wire you have now and attach a 12 ga jumper from that center dimmer terminal to the battery positive post and try the headlights and the dimmer.

1. You are using a ice pick tester with ice pick on the terminal and the clip on a good ground right?
2. You did put the negative battery cable back on, right?

OK, 1950 diagrams show that the headlight switch is fed by the ammeter. You say you have rear lights, so it seems like the headlight switch is getting power. SO either the headlight switch is bad or the wire to the dimmer center terminal is not connected.

DO NOT mess with what you have done. Leave ALL your work alone except if you want to test as I said at the dimmer center terminal.

You can check why no power to dimmer tomorrow, go slow and report here before you do anything. We don't want to get back into a mess again!
I don't know but you may have to drop and hang the headlight switch. Don't forget to disconnect the battery ground each time you start working on it.

Of course you need the battery connected to test for power at various places in order to figure out where power is interrupted.

As you know, previous owners can do all kinds of funny stuff to confuse us, so be aware of that. We will get this soon don't worry.

Reference pic

Yes. I checked, re-checked, and checked again before crimping any wires to make sure everything went where it was supposed to go so it's all wired according to that diagram.

Jumper wire to both terminals proves that wiring is correct, I guess.

So what's the likely suspect, pull switch?

What happened between starting the repair when pulling out the switch worked the high beams and finishing the re-wire that caused it not to work?

Is it strange that tail and park light setting works just fine?

Well I don't know what you did but this is what you were supposed to do:

If you want to test your work before investigating that problem. Take off the center dimmer wire you have now and attach a 12 ga jumper from that center dimmer terminal to the battery positive post and try the headlights and the dimmer.

You see here is the deal. YOU said
"Jumper wire to both terminals proves that wiring is correct."

I have no idea what terminals. I have no idea what the "proof" is. Something lit up when you did something?

OK, sorry. I didn't mean to confuse. Here's what I did:

I ran a lead from the + battery to the center terminal on the dimmer. When I pressed the dimmer switch in the cab it went from Hi beam to Lo beam as it should.

Lights worked on both Hi and Lo.

Can't really tell in the photos above but the first pic is Lo and second is Hi.

FARFEGNUGEN!!!!!!!!!!!!!!!!!!

Your wiring is correct and that's good. Stand by.

You have a wire unhooked from the dimmer that came from the headlight switch. Don't hook it back up. Follow it carefully back to the headlight switch. Eyeball it all the way back to it's headlight terminal to be sure it gets there unharmed, not broken or disconnected and in good condition.
Let me know if that wire has any other wires attached to it or it terminates and then continues off of something else...or there is any funny business from a PO.

Then stick the ice pick on that headlight terminal and pull switch knob out to see the ice pick light up or not. report back.

Also take off that jumper to the dimmer. Leave all that circuit you did alone. Nothing on the center dimmer terminal.

Think about anything you may have done to headlight switch or any wiring under dash that you forgot to tell.

If you followed instructions, you will also have a wire hanging and taped off that comes from the hi beam indicator that we will do later.

That's correct. The center wire on the dimmer is disconnected.

Tracing it might be difficult. I think someone wrapped all the wires in black tape. We'll see when I get under there.

Yes, wiring to headlights was a mess. Somebody used those crappy snap connectors with the teeth that clamp right over the insulation. There are zillions of them and they're all wrapped in black tape.

At the start of this thread the headlight switch pulled out and turned on the hi beam lights and hi beam indicator. At that point I did not investigate the switch or anything under the dash since it seemed like that portion of the system was OK.

So, I don't know what could have occurred to stop the switch from functioning. Other than pulling it out and pushing it in, nothing else was touched.

It really doesn't matter at this point, we are cleaning house. Unwrap, untie, untape the bundle and survey. Splay out each wire and discover it's to-from. Write it down. Make a drawing, whatever. When you find the headlight to dimmer wire, do the test and stop there. Report if terminal has power when knob pulled or not. Then STOP and wait for next step.

We are ONLY doing the headlight switch wiring/troubleshooting part for now. NOTHING ELSE.

Roger that vector, Victor!

Ya, it's all wrapped in sticky black tape all the way to the switch so it'll take a while to get that removed. I might not get it all done until tomorrow.

Now is the time to take your time. We want to go slow and be thorough so you have at least one good circuit finished. If it's easier for you, drop and hang the headlight switch to do that test. If you do that leave all wires attached to it and attach a jumper ground wire from headlight switch mounting threads or bracket to good clean metal. It may need to be grounded.

Tape up the wire that goes from headlight switch to the dimmer so it does not short out.

I appreciate the effort that bartamos has put forth to help you, and I appreciate your effort to follow his instructions to a T. He knows his stuff.
With your description of your harness with the Dime Store quality mash-on trailer light connectors and the sticky black tape, as well as your prior descriptions in other threads of the quality of the build which you are going for, you might want to consider replacing the entire wiring harness for peace of mind, and to achieve the quality of the build that you are shooting for.
That is just my 4 cents (adjusted for inflation).

X2

Carl and I have run into trucks we bought with all that stuff you mention. Back in our Dad's day, (actually my day too) all they had was sticky cloth electrical tape. After years of heat and cold cycling, that tape is how Gorilla Glue was discovered....or was it Phil Swift's Flex Seal?

Otto, Now that you have become a sparky, as we used to call the Electrical Engineers, I agree you are ready for a new harness after this.

Here's the story on this truck.

I refer to it as "mine" because for the time being , it is. It is owned by a friend of mine who has absolutely no mechanical ability or any knowledge of vehicles or how to work on them and lives in an apartment with no place to park it.

He bought the truck on a whim about 15 years ago because he liked it. Of course it sat in his garage for five or more years before I got it because it wouldn't run. That's when he sold his house and moved to an apartment.

I replaced the entire fuel system because it was clogged with rust, ethanol, etc.

First tune up and start after it's Rip Van Winkle period revealed that the #3 and #4 plug wires were reversed. Interestingly they had Sharpie numbers on them indicating their correct position but PO was obviously not too bright.

New wheels, tires, etc.

Anyway, I've succeeded in getting the truck to be usable and safe - at least during the daytime.

The owner pays for the parts and I do the work for free because I enjoy it and to help him out. He actually used the truck recently to move large items to a storage unit.

I try to keep the costs down as much as I can because I know he doesn't have much money.

So, as for the bodywork and paint, it's not going to happen.

But, Carl, you are correct in your assessment that I like to have things "done right" and do repairs to best of my ability.

A new harness would be nice but every electrical accessory on the truck, including the instrument panel and dome light, works as it should (Headlights excepted). I'd like to leave all that stuff alone if I can.