Turn Signal problem

[mrw]

I have a 73 240 with turn signal issues. My head, tail, and right turnsignals all work fine. When you turn on the left turn signal the rear brake lights on both side also flash (weakly). The front signals and running lights all operate fine.I have cleaned all of the bulb sockets and bulb contacts. It appears that they alll use a common ground but I am not sure. I have swapped out the turn signal switch with a spare and the problem remains. Any thoughts?

[jasper]

Check ALL grounds for rear bulbs.

Make SURE the correct bulbs are installed properly.

Make sure all bulb contacts, and the sockets are not corroded(That is the bulb's ground point)

 

The above are probably 90% of the causes of what you describe.

What bulb # is installed in the left rear directional position???

Edited May 26, 2010 by jasper

[mrw]

Check ALL grounds for rear bulbs.

Make SURE the correct bulbs are installed properly.

Make sure all bulb contacts, and the sockets are not corroded(That is the bulb's ground point)

 

The above are probably 90% of the causes of what you describe.

What bulb # is installed in the left rear directional position???

 

I cleaned all of the sockets. It turns out that my right signal bulb is not working at all but the lens was lighting up when the uppet light came on. The signal bulb is a single filament bulb. I swapped the left and right bulbs and the problem did not move. I suspected grounding problems but I do not know where the grounds hook to the body. I assumed that they were grouped together before they were grounded but I have not determined if that is the case. I will purchase a new bulb tomorrow and see if it makes a difference and then I willl add another ground to the taillights to see if the problems go away. If anyone has any other suggestions I would like to hear them.

[norwich]

A little patience and persistance will go a long way with this problem. Remember, your Z is almost 40. It's due it's aches and pains. Remember, it's not an American car with just one common ground. Your grounds are just as important as the hot wires. When my 77 stated having problems, I just made it simple. I got rid of the FI and all the wiring. I rewired the whole car with a litle heavier gage wire. I used relays and every connection was new. Ford makes an anti corossive grease that's awsome. Disney land uses it in all their electrical connections. Then, I spray Aqua net hair spray over all my connections. The USAF uses the same spray on their jet aircraft and call it electrical sealer. I know, I was a jet aircraft Mechanic during the Viet Nam war. Scrape off the OD green paint and you see the pink aqua net underneath. My point is: make sure ALL your grounds are clean. It sounds like you are getting some backfeed somewhere. Also, you can clean and regrease your T/S switch. If you swap it for another used one, who is to say it doesn't have the same problem? They are fairly easy to clean. Make sure your battery to body and engine to ground is clean. Hope this helps.