this has got me stumped, my right brake light works when i turn on the left turn signal, it goes out when the left turn signal is off. the bulb is good on the right side also??

 

This is a maybe: Check the ground back at the tail lamp assembly, I am guessing the brake light is pulling ground back through the turn signal curcuit.

 

ground is good, the ground also feed's the marker's and turn signal and those both work correctly. i will probably have to find a wiring diagram to figure this one out

 

More than likely in the turn signal switch.

 

the right turn signal also work's correctly, when i step on the brakes the right brake light does not work and the left side brake light does, when i turn on the left turn signal the right brake light works. the turn signal switch looks to be ok, no chaffed wires, none broken???

on the 4 pin wiring connector at the rear of the truck, all the power is there except for the right brake light.

a little more checking reveals that the four way's all work except for the right rear blinker???????? evidently the four way and brakes are on the same wiring circuit? any ideas

 

The four-ways, brakes and turn signals all use the same filament in the rear bulb. The turn signal switch is what keeps everything straight. It disconnects the brake power to the side the turn signal is trying to flash while allowing brake power to the other side. It might just be the wire contacts under the turn signal cancelling cam. You might be able to bend them back into position to let them work correctly.

 

man i have been tracking wires all day, i have found 2 wires coming out of the firewall in the harness only showing 0 to 6 volts, when i use a test light on those 2 wires it shows a very dim flashing light on my test light, there are no flashers or turn signals on????? the key is in the off position when i did this test also. i have tracked down those two wires to a relay? box, part number would be D7AF-9D844-AA, anybody got any ideas.

since probing with my test light on some of these connections it is now down to both side brake lights not working unless the other side turn signal is on, the four way's do not flash in the back but they do in the front.
anyone got a suggestion as i am about to pull my hair out!!!!

 

the key is in the off position when i did this test also. i have tracked down those two wires to a relay? box, part number would be D7AF-9D844-AA, anybody got any ideas.
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Would happen to be connected to the cruise control ?

 

good question milion, kinda hard to test it while i was sitting still with the dash torn apart in the garage. i did check all wires as i was activating the brake and one wire did light up when i stepped on the brake, probably the wire to disconnect the cruise control, two of the wires that were coming out of this box only had between 0 and 6 volts on them

if it is the cruise control relay box then i guess i can eliminate that from my problem

 

It is really helpful for users to post the wire color scheme they are discussing ,so a check in a wiring diagram could be done

 

Are you sure the ground is good? There should be one behind each rear light. I like to use sand paper and clean the mounting area and the connector, then use dielectric grease. A bad ground can cause some really goofy problems.

There is a good tech article that covers troubleshooting the rear lights.

Keep in mind the rear lights should light up as follows...
just brakes - both R and L lights lit
just R signal - only R light blinking
just L signal - only L light blinking
R signal and brakes - R light blinking and L light solid
L signal and brakes - L light blinking and R light solid
headlights with no signal or brakes - both lights lit but dimmer than brakes

Marty

 

thanks i am well aware of how they should be working, and yes i do beleive the ground is good on account that the turn signal and marker light are drawing from the same ground screw.

milion it probably would be very helpful if users posted the color of the wires but being color blind it makes it kinda tuff

on the cruise control box as posted above there is a gray and green connector, on the gray connector with the brake pedal energized i have power at the brown wire on the left side of the gray connector, i have no power coming out of the green connector. i disconnected the cruise servo wiring and i have no power at any of the connections there, i would think there should be at least one of those connectors energized to shut off the cruise? is there suppost to be a power in/power out wire on that cruise control box?
the brown wire going into the gray connector i think is the "hot" wire to tell the box that the brakes are on.

on the hazard switch there are six wires

left side has
1= light blue---------------------------4= solid blue
2= orange w/white stripe-----------5= white w/blue stripe
3= solid white-------------------------6= white w/black marks

with the key off only wire 6 has 12 volts

with the key on
1=11.23v--------------4=11.22v
2=0v--------------------5=0v
3=5.86v----------------6=11.24v
on the turn signal cam there are two wires, a blue and green
with the key off neither have power
with the key on start mode the blue wire has 11.23v and the green wire has 5.86v

hope this wasn't to much info but i would like to see if i could get this finished up, i am almost starting to think it is a short in the hazard switch???

 

hey macguyver, you were right it is in the turn signal cam, after ripping apart the dash and almost the entire steering column and tracking wires the metal tabs are not in the right position to be making the correct contact under the cam

all thanks for the help