Turn signals not workin- stumped

glenn in encinitas

glenn in encinitas

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Hey coupesters- I am looking for ideas on how to troubleshoot inoperative turn signals.

Background:

1970 2800 CS- originally auto, converted to 5-speed.

The other day I pulled out and smelled the dreaded electrical smoke. Shut down immediately and pushed into garage. No fire, so that was good.

After inspection, the turn signals were inoperative. Fuses all good- pulled and checked contacts. I pulled the turn signal relay and it was clearly scorched. I purchased a new one, installed it and still no turn signals. Not good.

Then, I pulled the turn signal switch, and saw obvious chafing and evidence of a short along the harness where a PO had performed some repairs using black electrical tape. This was too easy, right?

I repaired the switch harness by cutting out the damaged wires and replacing with new wire (soldered the joints).

I also noticed the black wire connecting "W" and "15" on the back of the switch had come undone. I re-soldered it to make positive connection.

Reinstalled turn signal, plugged in the 9-pin connector and the white single-spade connector. Still no turn signals. But, they all still work via the emergency flasher.

Current condition:
New turn signal relay
Repaired damaged wires on turn signal harness.
Repaired disconnect between W and 15 on the switch.
Turn signals operate properly when emergency flasher is activated.

When I try to activate turn signals via the stalk switch, nothing happens.

Any ideas on how to troubleshoot the turn signal switch (p/n 61 31 1 351 852)?? Electrical schematic not exactly clear to me. At close to $500 for a new switch, I'd like to exhaust my options if possible.

Thanks in advance for your thoughts!
 
glenn in encinitas said:
Current condition:
New turn signal relay
Repaired damaged wires on turn signal harness.
Repaired disconnect between W and 15 on the switch.
Turn signals operate properly when emergency flasher is activated.
Click to expand...

When was the new flasher unit (what you refer to as the "relay") installed? Was it done after the electrical glitch? In other words, did the turn signals ever work with this flasher unit?

The fact that your emergency flashers work suggests that the problem may not be too dire. It could be as simple as the wrong flasher. e9 (and 2002 and Bavaria) flashers are very sensitive to bulb current draw, so they will sometimes work when all four bulbs are drawing current, but not when only two are.
 
Flasher relay installed after the original episode. I will replace all four bulbs and see. Has anyone taken the turn signal switch apart to see what magic is inside?
 
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HB Chris said:
Probably just a can of worms?

:)
Click to expand...
No Worms! There is a small brass jumper missing from the one in this photo..it sits on the arm portion and slides to the various posts to do its thing.

Double check your fuses and make sure your getting power across all them. Don't know if e9s are susceptible to it but have see the actual fuse post melt the plastic in its housing and loosen the connection (happened both on a 240Z and 308GTB of mine although both use the glass fuses) I can't remember for sure but the E flasher circuit may also be on a different fuse which could account for them working.

Cheers
Mark
 

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My bet is bad emergency light switch. The 12v for the turn signals go through it and the event you had may have fried it. You can try to bypass it and confirm I am right.
 
Arde said:
My bet is bad emergency light switch. The 12v for the turn signals go through it and the event you had may have fried it.
Click to expand...

I like that theory. The emergency light switch controls where the flasher draws its current - it allows the 4-way flashers to work with the ignition off, but the turn signals to only work with the ignition on. So yea, if the set of contacts that sends +12 from the ignition switch to the flasher are fried, that might explain your symptoms.

glen in encinitas said:
OEM flasher relay. Not cheap either!
Click to expand...

In that case, I wouldn't mess with the flasher further until you get the turn signals working. I was thinking you might have installed a generic, heavy-duty flasher. Electronic flashers solve problems like the exterior lights working but the dash indicator only blinking a couple times. Or supporting LED bulbs which draw minimal current.

But don't throw out your old flasher - if Arde's suggestion solves the problem, then the old one is probably OK.
 
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Follow up: Arde's theory seems to be correct! Checked for current at fuse 4 and it was OK. Followed path and checked current to round plug into back of hazard switch (30) and it was OK. Did not have current to R or L. Jumped the round plug from 30 to 49 and voila.

I pulled the switch apart (not too tough if you worry less about depressing the several tabs and just pry the outer part away- it is fairly flexible. Once opened, I tested continuity at various tabs and straightened the locking armature while I was there.

For some reason, I was not getting continuity between the inside metal strip associated with connection 30 and the tab that is on the outside of the switch housing. It appears they are not one strip of metal. Instead there is the interior strip and an exterior tab that is "L" shaped and they are joined by a hollow brass rivet. It seems the rivet had broken down, causing a very weak connection. The electrons can't flow very well in that situation and things got hot. That made things worse, etc.

I cleaned up the melted plastic and the hole where the rivet had been, then I flowed a good bit of solder through the hole. We now have a better electrical connection than new. Replaced hazard switch and all is back to normal.
 
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Wow, I have to carry this burden of being right even while on vacation...

Enjoy the turn lights.
 
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