POOR Brake Lights ~ Thought I Fixed Them ~ HELP!

[ersatz]

My ride is a '46 Ford 1/2 ton PU, stock V8 flathead, 6 Volt system running a 40 Amp alternator. All wiring was redone in the early 90's.
The weather here at the Jersey Shore was IFFY today, so I decided to work on my brake & tail lights. Before starting work, the brake lights functioned alright and were fairly visible. I have a third LED brake light in the rear window that works just fine. The left rear signal operated fine, but the right signal was slow to light and somewhat dim. I realized the bolts holding the brackets and housings were stainless steel, so I decided to replace everything with steel bolts for better grounding. Well, I dismantled the tail light brackets & tail light housings and made sure the contact points where bolted were clean metal. Found alot of rust under the attachment points. I put everything back and the reverse happened. I now have 100% improved left & right rear signal lights, but POOR brake lights which are very Slow to come on & Dim.

I don't know what went wrong? Thought for sure that the brake & signal lights would both be much improved. Didn't expect the reverse.

What can I do to right this situation?

[ford1]

now go and do the same with the other lite, MAKE SURE all the connections are clean and tight, especially the grounds

[expavr]

On my 40 tonner I ran a #12 ground wire from each taillight bucket directly to the frame which made a big difference in both the reliability and amount of light from the buckets.

[PeteVS]

I have an older car with a non-metalic body. EVERYTHING on the car has a ground wire, all of which are tied together. Instead of running a ground wire from a light to the frame where there will be a connection that can go south, run wires from all the lights, etc, tie them all together and then run that wire to the engine or wherever the battery ground attaches. IMHO

[ersatz]

Okay, I took #12 wire and grounded each tail light to a clean spot on the chassis. It no doubt helped the total setup, but I still have slow - dim brake lights. Got super bright signal lights & running lights. I will use a volt meter and check everything out from back to front. Thank you everyone for your help!

[lee34]

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Have you checked to see if the running lights and brake lights are switched so the proper element is not receiving voltage as needed ? lee34

[Zeke...PA]

I would jumper the brake light switch to see if that is the source of the problem. Zeke

[BILL WZOREK]

Ersatz
Sounds like the brake lite wire is wired to the wrong filament.
May have brake and running light wires crossed.
Running light should not be as bright as directional or brake light.
You probably all ready knew this but some times we are so close to the problem that we can not se the LIGHT. LOL LOL

BILL W

[Cecil/WV]

Sounds like the problem is in the brake lite circuit and not the ground if the tail and turn lites are bright.

[oldblue]

I never like to depend on a chassis ground , instead I run a ground wire to everything from a grounding buss that I locate under the dash . Check the voltage drop across your brake light switch .

[George/Maine]

If your signal lights are good in back thats true flasher.
Brake light wire goes from battery to brake light switch to signal light swithch.
Check ends of wire pull ends, maybe only few strends of wire,or poor connection.
could be bad brake light switch.

[ersatz]

Originally Posted by lee34

Have you checked to see if the running lights and brake lights are switched so the proper element is not receiving voltage as needed ? lee34

Yes, checked that possibility by reversing wires. Still the same! Haven't gotten my hands on a volt meter yet.

[Mart]

You have checked it, but it is worth mentioning on these early vehicles, the twin filament bulbs do not have offset pins, the bulb can be put in either way round, but only one way is right. Later on, the bulbs and sockets with the offset pins were introduced so they would only go in the right way round.

Mart.

[ersatz]

Finally had time to get back to the problem. With the help of my buddies volt meter, we found the brake lights were only getting 4 volts. Everything in the rear area checked out just fine, so we proceeded with the stop light switch and wires under the dash. Found some bad connections under the dash coming from the rear conduit. Didn't want to get into that mess, but after sorting it out, it did pay off.
Thanks to everyone who gave their input! Safe Cruising, TED.....