Turn Signals

[Kilgon]

Need some help on this one.  Finishing putting the dash in and everything is finally working ok except my turn signals.  When I turn either the left or right side on all signals lights flash on both sides front and back.  Also both lights in the dash flash too.  It is like having my 4 way flashers on.   The 4way flashers work fine. 

 I have put in led bulbs in the dash except for the turn signal indicators - they are still incandescent.   All exterior bulbs are incandescent.  Taking a long shot I have replaced the flasher with no luck.  If I am reading the post I found the led's in the dash should not be causing the problem since they are not in the turn signal circuit.  Tried tracing  the problem down but not having any luck.   :huh:

Don't want to be chasing ghost and replace the turn signal assembly without knowing that's the problem.  Any ideas or help would be highly appreciated.

 

[Don C]

I would start with the turn signal switch. #2 would be to check for pinched wires in the steering column shorting out.

 

[Kilgon]

I would start with the turn signal switch. #2 would be to check for pinched wires in the steering column shorting out.

Thanks for getting back. Been working on it all morning.  Was getting frustrated due to couldn't find my schematics and the new wikipedia is missing the rear lights for the 71.  Was working in the dark for awhile.  Finally found my manual.  I was pretty convinced it was in the switch but I ohm out the wires and all showed ok - no shorts.

I think I have a short in the front harness.  Started ohming out the wires to the front and back to check for shorts.  Was showing shorts in both.  Duh!  Had light bulbs in so was feeding back through the ground.  Disconnect the rear harness at the driver side kick panel and took lights out and then the rear checked OK.  The front shows a short.  Might have pinched some wires putting the dash in or putting the harness connector together. Tried to look but didn't see anything.

My current game plan is to unwrap the harness where it goes over the shock tower and cut one of the wires there.  I'll ohm out again and see what side it is on.  If it's back to the dash I'll just run a new wire.  If it's in the front of the engine compartment I'll have to track it down and fix it.   I'll post my end fix when I get it working.

 

[Kilgon]

Update - Got them working.  After cutting one of the wires at the shock tower going out to the turn signal I was able to  isolate that the short was from there to the inside of  the car.  Ran a jumper from the turn signal connector out to the front part of the wire and still no luck - both sides flashed.  WT&^*(%!.  Needed to cut the other end also at the connector.  Turn signals work fine but both of the indicators were still flashing.  Short had to be at the cluster connector or printed circuit board. 

I had just put the dash in Thursday.  Needed to move the steering column so I had to pull the instrument cluster out to get to the bolts on the main bracket that supports the steering column and brake bracket.  Car had a/c and the drivers side vent duct work goes across the top right behind the back of the cluster making it impossible to get behind it. 

I know the contacts on the printed circuit are coming off the mylar and it has been on my wish list to replace when I have a few extra dollars to spend.  Came to the conclusion that the problem had to be there.  Made a saddle cut on the a/c duct so I could get it out and get access to the back of the cluster.  Removed the connector and made sure the copper tracks were lined straight.  Have about 4 loose off the mylar.  Plugged the connector back in and BINGO!  Everything working fine.  4 hours of fun and joy today!

 

[midlife]

You definitely need to replace the cluster circuit card if 4 Mylar strips are loose.

 

[1sostatic]

You definitely need to replace the cluster circuit card if 4 Mylar strips are loose.

Yeah that's how car fires come about - once the calorific value of that mylar goes due to heat from small intermittent flash-over events,  it acts like a wick.

I had to do repairs to e39 platform BMW dash circuit boards due to similar events.  

I wonder if those cards can be rejuvenated and today's con-formal coatings used to prevent nasties. :chin:

 

[midlife]

You definitely need to replace the cluster circuit card if 4 Mylar strips are loose.

Yeah that's how car fires come about - once the calorific value of that mylar goes due to heat from small intermittent flash-over events,  it acts like a wick.

I had to do repairs to e39 platform BMW dash circuit boards due to similar events.  

I wonder if those cards can be rejuvenated and today's con-formal coatings used to prevent nasties. :chin:

Or get a hard-wired dash cluster harness that completely gets rid of the circuit card.

 

[Kilgon]

You are both correct and I need to get it taken care of. Now might be a good time for me to do it with the money we are going to be getting from the stimulus package. Plan on using it to finish the exhaust and stripe decals plus a few other items to finish my build.