Gear position indicator panel mystery

[Doctor J]

Many second generation owners are complaining about strange illumination of the shift position indicator panel located to the right of steering column
When selector is in park the both P and R indicators are illuminated in about a half of normal brightness in the reverse position R is off and in neutral R and N are illuminated similar to P and R in park position.
D, 2 and L are illuminated normally [however the D can be out due to the burned out bulb):]
Some enthusiasts try to fix that problem by cleaning the neutral safety switch, but this problem is related to the printed circuit defect [see the first two photos]
P, R and N indicators are sharing the same tracer, which connects them to the ground; this tracer goes from these bulbs to the other side of the board via hollow rivet-like feature, [next to the yellow mark] and then the tracer continues on the opposite side of the board from rivet [yellow mark] to the ground terminal [another yellow mark].
2 diagrams below show the current flow with good and broken tracer:





When the ‘rivet ‘ fails, but the reverse bulb ok, the current flows trough bulb to the ground via non-energized back-up light circuits. In reverse position the alternative ground becomes power source, but neither P nor N indicator circuits can be used as alternative ground if main ground tracer is broken.
This problem is not happening among the cars equipped with different design of the circuit board.

Tools and materials;
Regular length and stubby Phillips screwdrivers;
Phillips screwdriver
Soldering iron
Analog multimeter
Knife and tweezers
Soldering wire
1 inch long stranded wire
To repair proceed as follows:
Remove instrument cluster trim and unplug wiring ;
Remove indicator panel assembly
Remove circuit board
Check continuity of the tracer from the bulb to the ground terminal
Then solder small strand of copper wire as illustrated, using small soldering iron and electronic grade rosin core solder.
Verify repair
If desired, the L bulb can be swapped with D bulb to prolong its life;
All ‘rivets’ can be done as described above while board is out

[zppeacock]

Great Write up. I got one question though... Are the Normal and PWR light in the same circut? My normal light comes on sometimes, and the PWR one always works when I press the PWR button.

[kesando]

My pwr doesn't work at all. All others seem to work fine

[JMSports]

Originally Posted by kesando

My pwr doesn't work at all. All others seem to work fine

My PWR light doesnt ever work, NORM works like once every couple weeks, N light doesnt work, but other then that.

[Doctor J]

to Zppeacock:
I have had the same problem in my car; it turned out to be a bad bulb

[cam cam]

fabulous write up . i've never soldered elec. stuff before though. i just dont know? will that repair also fix my intermitant backup lights problem too?

[zppeacock]

Originally Posted by Doctor J

to Zppeacock:
I have had the same problem in my car; it turned out to be a bad bulb

Thanks
?
Also where the shifter is does the PRND2L light up?

[nuron]

Originally Posted by cam cam

fabulous write up . i've never soldered elec. stuff before though. i just dont know? will that repair also fix my intermitant backup lights problem too?

Are you talking about the reverse lights? There's a yellow box on the left side of your trunk behind the carpeting that could be replaced. Also check your wiring harness at the trunk hinge, very very common occurrence making the lights go haywire.

[cam cam]

thanks nuron, i'll check it.

[rocknrolldude89]

Originally Posted by zppeacock

Thanks
?
Also where the shifter is does the PRND2L light up?

I have the same problem with my '91 LE. The lights down by the shifter come on only so often. I discovered that it i tap the right hand side of the base, it causes the lights to come on.

My indicator lights come on randomly and rarely. Sometiems they'll work perfectly but more often than not the D and NORM lights aren't on (while in drive).

[Darwin686]

Dr. J Thanks for this kick ass post well done!

Senario:
I have replaced my gear shift indicator cause somebody swapted mine in the past with one that did nto have the over drive light, need to get thoes codes!. Ok so I havethe same board and the same problem. I was a bit supprised after changing the bulbs in the board to discover this was happening with board. From the electrical work that i've done in the past i figured it was a feedback loop from somewhere. Glad I found your post I plan on doing this tomorrow. The odd thing is after sporting a driving sessionin my swagger waggon I can go from drive to park with the lights working properly yet each time I start the car same issue. So I'm assuming the riviot point your speaking of / sodder point is in a state of pre-fail. This version of this board, I believe was in all trac models. I've got the norm and power features and I know they won't work with my standard camry base .

Understanding of your solution.
Essentially it looks like a sodder point has failed and you have extended the circuit from one side of the board to the other? Am I correct?


My solution:
I plan on taking advantage of the sodder point and using a tail off of an LED and putting it through that point, it should be hollow and a LED tail should fit through it. Then simply sodder the connections


What are your thoughts? And did I understand your write up correctly?

[Darwin686]

Dr. J

Just wanted to thank you again. Great write up and it was the exact problem. I did a slight variation of what you did but essentially the same thing I have never seen a circuit board liek this one that did not want to take sodder. Kinda interesting.

This was a great post and thanks again! Only three more things to back to normal.
1. Struts
2. Small Rust repair
3. Reseal lid mounted tail lights