[64speed]

I am starting from scratch for my car and so far up until 3 nights ago everything was going swimmingly. when I plugged in my ribbon harness my taillights work but one is brighter than the other and is out of sync with the brake lights. Depending on whether I am pressing the brake pedal one will get brighter and the other dimmer, if I turn the flashers on that could change sides or it may do nothing at all. Sometimes pulling the light switch out makes them light up full capacity like the brakes are on and sometimes it doesnt. I have no turn signals. If I turn the signal on it lights up and the flasher clicks once and then the bulb just stays bright. I cant get it to click by touching a test light to the purple wire coming out of the column but it will again only click once and I have to remove the probe and insert it again to get the light to flash. I have no hazard lights even though I have the adapter from IDIDIT. It is an aftermarket column. My only thought is my bodyman painted everything that wasnt bolted down so I am not getting good grounds but outside of that I have been messing with this for 3 days and am at a loss. everything from the firewall forward works. Help please

[bill ryder]

Since you said all is OK up front, I would start by unplugging the ribbon harness at the fuse box and verify what you have there. Depending on the results, plug it back in and move to the trunk and unplug the ribbon harness there to see what you have on it there.

"Bill"!

[lfdsteve]

Ground issues until ruled out.

[gobrdgo]

Originally Posted by lfdsteve

Ground issues until ruled out.

It’s always the ground ha

[george kujanski]

Check grounds first.

George

[Lemans64]

Ground issues, LOL. bad grounds have a tendency to do weird things, power is looking for a place to go it finds a way that is not really the way we want it to go.
IE back thru wires or thru other parts of bulb that are connected thru the ground circuit in the bulb housing, and since the housing may not be grounded correctly
it feeds back thru the other wire to find another ground source. So ya weird things happen, dim bulbs, etc.

[64speed]

I was leaning towards grounds but this is my first rodeo with a rewire. Where should I start?

[Lemans64]

Rear light housing is best place to start. Also make sure the front light housing as grounded as well. There should be a ground wire from engine to frame. And frame to rad support.
One way to check for bad ground is to put a test light on the taillight socket where the bulb goes in, not the electrical part just the side of housing.
If the test light lights, it has a bad ground. I believe the housing is the ground for the rear lights? If so the housing itself needs to be grounded to the body
by hold down nuts?? or make a ground wire that goes from housing to a clean bare metal part some where.

[64speed]

Not trying to be obtuse but what’s the best way to attach these grounds cause I don’t want to have self tappers everywhere nor do I want to be grinding paint off everywhere

[Lemans64]

There should be a ground wire at the trunk latch support if I remember correctly, this position could be used for other ground wires as well.
Usually there is a ground strap that goes from engine to frame and another small one going from frame to inner fender or rad support.
Any bolt can be used but cannot be rubber insulated.

[64speed]

Thank you, I am starting from scratch so it’s a little overwhelming

[64speed]

I changed my battery ground from the brackets to the head. I grounded the head to the frame and the frame to the core support. Now I have consistent taillights but no brake lights. When I hit the pedal the lights go out. New symptom

[Lemans64]

Try using a jumper cable or wire from the tail light housing or taillight socket to something metal, Trunk latch. May not be enough ground
to run all the lights. Just for a quick test. If the housing nut rear was painted real good it may not ground properly, and may be using other wire to run ground
for parking lights, then as you put power to brake light wire the ground goes away. Hope that makes sense??

[64speed]

Nothing you guys can do about it but I am more frustrated by this than anything else in the build. Every time I follow a suggestion I won’t say things get worse per se it’s just that the symptoms change and it’s pissing me off

[johnta1]

Turn signals work? (without brake on)

Make sure the bulbs are installed correctly and are the double filament ones.

Are these new tail light sockets?

Forgot to ask, check for 12 volts at the brake switch. And for 12 volts at the tail lights.

[64speed]

Wiring this car to me is by car the hardest part besides the taxing physical stuff.

[64speed]

I appreciate all the suggestions you guys have and keep them coming

[64speed]

I am an idiot but just so you know because they don’t sell it M&H does not color code the ribbon cable. It will plug in both ways. I am proud to say I figured this out on my own in the grocery pickup station at Walmart though.

[johnta1]

CONGRATS!!!!

[Lemans64]

Glad it was something simple.