sorry thie was a duplicate post

 

The saga continues:

- replaced bulbs and sockets (metal and no dif if in or out of hole)

- From the flat disconnect in the engine compartment I ran the three
wires outside the truck directly to the rear lights as per the trucks
wiring documentation.

- have running/parking lights at correct lumination front/back

- have turn signals at correct lumination front/back

- have very low illumination on correct filament when apply brakes( it
appears that the larger filament is for running/parking lights and the
smaller of the two is for turn signal/brakes).

- I inspected the engine compartment and could find no loose connects or
frayed wiring connected with the brake system.

Thoughts or suggestions on where to go next would be appreciated.

thanks

ronindog

 

You just figured out your own problem. IF you have only 2 wires going to the sockets, AND they work the same weather they are inserted into their metal holes or not, then your GROUND is the problem. The hole in the body where the outlets fit into is NOT GROUNDED.

Hook up your original connections, and then try running a wire (as I sugested above) from the (-) terminal of the battery to the metal outlet. This should correct the problem. IF it does, ADD a ground from the body to the (-) battery post. Make sure the metal sockets are securly installed in the metal holes (the body of the connector to the body of the car IS the electrical connection for ground).

To do this, Just drill a hole in the body somewhere under the hood (firewall usually works well for me) and use a sheet metal screw to attach a wire there. I reccommend using at least a 10 gauge wire as this ground path is used for more then one think it is.
Then just run the other end to the (-) side of the battery. I usually just use a ring terminal and hook it to the bolt that tightens the clamp down on the post.

In case you were wondering, The power goes from the battery (-) to the frame (ground) to the body, to the OUTSIDE of the metal socket (also ground) through the proper filament (lower, larger one for brakes and turn signals, higher smaller one for running lights -- at least in an 1157 bulb). to the electronics under the dash to the fuse to the battery (+).

For some reason, when the ground is removed, the lights on ford vehicles will behave strangely, but still almost work.

Again,

hope this helps.

 

sadly that isn't the issue, however-

as a update: I have running/parking lights and the turn signals(all) work properly with the proper filament lighting up when the brakes are applied. The brake filament however is "dim", not at full strength.

ran a direct ground line to the lights from the (-) battery post and the result:

- with ground to BOTH rear lights things are the same as noted above

- with battery ground to one of the rear lights get a brake light on one side(though brighter, no the brightest level) while the opposite side running light if lit, dims.

Would appear still a ground/shorting issue.

thoughts?

ronindog

 

The larger brighter filament should be the turn/brake lights. That is a small matter though, which can be swapped later.

What it is looking like now is something is wrong with the turnsignal switch area. From the sound of the wire colors, it looks like someone has used universal trailer wiring to wire the truck up.

It also sounds like you have everything handled as far as wiring to the rear. What I am curious about know, if my hunch is correct about the non-original wiring, is how they wired the front up.

The brake switch power and the turnsignal flasher power both feed into the turnsignal switch. The turnsignal switch mixes this al together, since the large rear filaments have dual duties. They are the turn signals and the brake signals together.

 

it does appear that truck has had extensive rewiring.

i noted on the schematics that as you indicated the brake lights, signals etc goes into the turn signal unit

the vehicle also has power brakes, an aftermarket unit that has a power in source and single line out that goes into a tape wrapped bundle under the dash. goodness knows whats in that spaghetti.

any thoughts on how to check out the turn signal unit and more practically, where is it located?

thanks

 

Ok, the problem seems to be the brake circuit(brake lights are dim) correct? The brake circuit starts at a power source in the fuse box, runs to the brake switch(which is either a pedal operated switch or a pressure switch), then out of the brake switch to the turnsignal switch, which is usually mounted in or around the steering column.

See if you can get at the turnsignal switch wiring. See if you can find the brake pedal switch power coming into the switch. You should have 12 volts on this wire when you push on the brake pedal.

If you get that figured out, then try to find the two wires coming out of the turnsignal switch going to the rear. There should be a left and right wire. With the turnsignal switch in the center position, push on the brake pedal. You should have 12 volts on both of these wires if the switch is in the center.

I would make sure you have all the rear lights hooked up(temporary is ok) while doing these tests to put a load on the wiring while you are reading voltage with your meter.

 

yes, the lights are dim and it is a pressure switch off the power brake unit

i'll check if i can get to the turnsignal switch and run the checks and let you know what i can find.

have a pleasant evening

ronindog

 

for those of you still with me on this epic journey:

when i checked the voltage "out" of the PB unit it was something less than optimal.

someone had wired the power to the PB unit through the starter relay?

there was a hot wire that had been cut coming through the firewall with the correct voltage,

so

- disconnected the wire to the starter relay,
- tied in the hot wire that came through the firewall, the same hole, two
wire rubber gromet which apparently was a hot wire back to the fuse box
- and ?

got real solid running/parking lights AND my brake lights,

HOWEVER, they were flashing when applying the brakes!

went to the fuse box, pulled the flasher and checked wire hookups

found the battery hot wire and flasher wires reversed

routed the battery hot wire where it belonged and same with the flasher wiring.

NOW I HAVE

solid parking/running lights

solid brake lights

good low and high beams

AND

SOLID FLASHERS, not flashing flashers/turn signals, SOLID FLASHERs

also,

if I leave the flasher gizmo in, my fuel pump runs like a flasher, on off, on off, when the engine is turned off. mmmm?

I'm telling ya, you have to have a sense of humor or you'd shoot your truck.

So -

Pulled the flasher so I don't have a pulsing turn signal, though I can do that manually with the turn signal dohicky

I have running/parking lights and solid brake lights.

I had the fuse box replaced when the truck was in the shop and apparently they really screwed things up.

I guess if I'm brave enough I can trace back the wiring and connect the right wires to the rights fuse connects etc and that may solve the problems

In the meantime I can run the truck and feel confident all lights, especially the brake lights are operating correctly.

By the way, the smaller of the two fimlaments are lighting up when applying the brakes so is there a simple solution to that?

In retrospect I should have checked the power in and out source at the PB unit first to ensure I was getting enough juice.

Then the grounding at the back and next, the bulbs and sockets.

Fineally, the fuse box to ensure that the wiring into the unit was correct.

Again, thanks especially to those of you providing suggestions on how to work through this. Hopefully it can be of use to others with similar issues in the future.

Have a great day.

ronindog