turn signal turmoil

[911pby]

I've been working through some lighting problems with my 1979 SC and have benefited enormously from the wisdom on this forum. Following the advice of many, I studied the wiring diagrams, dismantled the light assembles, cleaned or replaced the connectors, and cleaned the grounds. I replaced the non-working four-pin flasher with a three-pin Novita E36, grounding the unused C slot in the flasher socket. I replaced the turn signal switch with a new one, and now the high beams, low beams, and high beam flasher work fine. Even the "parking light" feature (parking lights on L side illuminated if ignition is off and turn signal stalk is pulled down; and vice versa on the R side) works. I've checked the fuses and they are all good. I've checked continuity between the turn signal switch all the way to the fuses and can't find anything wrong.

But the turn signal lights are not activated by the turn signal switch!


I've searched the archives and poured over the wiring diagrams but I can't seem to figure this one out. For some reason, although the hazard switch and the flasher seem to work fine, the turn signal switch doesn't seem to be communicating with them!

Any advice would be greatly appreciated!

Thanks

[targa80]

I have several questions for you so I can better understand your problem.

1) You said "But the turn signal lights are not activated by the turn signal switch!" When you said turn signal lights do you mean if the turn signal switch is selected for the left turn that the exterior front and rear turn lights do not flash on and off and the tach left directional light does not flash?

2) if you select the hazard flasher switch does all four external lights front left/right and rear left/right lights flash and the two tach directional lights flash?

[DRACO A5OG]

Not for nothing but check the fuse, it may look good but insure it is snug and properly seated. Also I know you know this, but did you make sure the key was in the on position when testing the signal?

[911pby]

Pat
I will try to clarify my problem (and thank you for all your informative posts here re: electrics and our 911s).

When the hazard switch is on all four turn signal lights and both turn signal indicator lights on the tach flash in unison. When the turn signal switch is activated (either left or right), none of these lights flash or even illuminate.

The wiring is stock apart from the mod you posted (grounding C terminal on flasher relay socket and using 3-pin flasher relay. However, while trying to diagnose the problem I followed one recommendation here and grounded the blue wire running from tach t.s. indicator lights to the C terminal (grounded it with the rest of the dash lights). It made no apparent difference, and when I restored the original wiring (running to the C terminal) it made no difference either.


Draco,
I will check the fuses again but they seem OK and the hazard flasher operates the turn signal lights as described above. The problem exists whether the ignition switch is off or acc. or on.

I'm sure I'm overlooking something obvious, and welcome all suggestions and advice.
Thanks
Jeff

[fintstone]

The larger cable (group of wires) coming off your turn signal assembly has a plug at the end where it plugs into the bulkhead. Sometimes it gets partially pulled out. If you have not already, unplug it and plug it back in, making sure it seats properly.

[silverc4s]

Check that the flasher switch is connecting the turn signals to the t.s. Switch in the off position. This switch generally will take the turn signal switch out of the circuit while flashing is desired.

[universeman]

I have a similar problem in that the right hand flasher on my 82SC works perfectly front and back, and the exterior lights on the left flasher work perfectly, but the *indicators* on the dashboard when you signal left, both flash (meaning both right and left indicators - like hazards - when you have the left turn signal on.)

I believe this is related to the left taillight housing which is rusty and sketchy in general. I'll try to chase this down and post back my findings, but if anyone has any ideas on this issue and how it might relate to 911pby's, I'd love to hear it!

[911pby]

Bill, you said "Check that the flasher switch is connecting the turn signals to the t.s. Switch in the off position. This switch generally will take the turn signal switch out of the circuit while flashing is desired."

Does this mean that if the hazard switch is "on" the turn signal switch cannot communicate with the flasher (or the turn signal lights)?

If so, is it possible that my hazard switch is defective in some way that prevents it from turning completely "off" and enabling the turn signal switch to work -- even though the hazard switch is in the "off" position and is not activating the flasher?

How would I check to see if this is the case?

Thanks
Jeff

[fintstone]

The hazard lights are powered separately.

[fintstone]

Originally Posted by fintstone

The larger cable (group of wires) coming off your turn signal assembly has a plug at the end where it plugs into the bulkhead. Sometimes it gets partially pulled out. If you have not already, unplug it and plug it back in, making sure it seats properly.

Did you check this?

[pete3799]

I went round and round with my flashers. Tried every flasher relay I could find locally ( even ordered some) none of them worked correctly. Finally ordered the expensive one from Pelican and everything went back to working correctly.
Hella part # 914-618-303-11-m44 $56.00


Edit: They don't seem to list the M44 version anymore. Purchased mine 6/13/12

[911pby]

Originally Posted by fintstone
The larger cable (group of wires) coming off your turn signal assembly has a plug at the end where it plugs into the bulkhead. Sometimes it gets partially pulled out. If you have not already, unplug it and plug it back in, making sure it seats properly.

Yes, I have done that several times (including when I replaced the turn signal switch.
Thanks
Jeff

[911pby]

Flintstone, you said "the hazard lights are powered separately."

Can you help me understand? I saw a previous thread where someone had a problem similar to mine and you advised: "…your flasher relay is most likely good and so is your turn signal switch. You are probably just not getting switched power to pin 49 when you turn on the key. Your problem is probably fuse 11…"

Is this what you meant?

Sorry to be so thick-headed about this, I'm on the steep side of the learning curve when it comes to electricity, but I'm working on it.

Jeff

[targa80]

Originally Posted by 911pby

Pat
When the hazard switch is on all four turn signal lights and both turn signal indicator lights on the tach flash in unison. When the turn signal switch is activated (either left or right), none of these lights flash or even illuminate.

Well this is good news because it reduces the fault to a very small area in the turn signal/hazard circuitry. My comments are going to be based on the Model 81SC schematics. I have used these schematics for my 80SC so I believe they are applicable to your 79SC. I use these schematics because they are much easier to read verses the Model 78SC schematics. I will take you thru the current flow of the hazard switch first then we will discuss the turn signal switch and possible faults areas. This is going to be long winded and might be confusing, but it is what I would do to isolate the failure. There may be a shotgun approach to fixing your problem but I prefer to test my way thru the failure.

When you energized the hazard switch you provided the 12 volts directly from battery thru fuse 17 to the hazard switch input pin 30. The hazard switch then provided this voltage internally to output pin 49 which connects to the input pin of 49 of the flasher relay. The flasher generates the pulsed voltage on output pin 49a when it has a path to ground via the left and right turn signal lights. The hazard switch when energized provides this path to ground for the flasher pulsed voltage output via the pin 49a on the hazard switch. (This wire is also tied to the input of the turn signal switch, but is not a factor when using the hazard flasher switch) The hazard switch sends the pulsed voltage internally to output pins L and R that connect to the front and rear left and right flashers lights respectively. The two tach indicator lights are also tied to the L and R output pins.

As I said earlier this is good news because we are now only looking at possibly 3 or 4 locations that can effect the turn signal operation.

Normal operation, hazard switch is off, ignition switch is on and provides switched 12 volts to fuse 11. Fuse 11 outputs switched 12 volts to input pin 15 of hazard switch. The hazard switch routes the switched 12 volts internally to output pin 49 which is connected to input pin 49 of the flasher. The flasher generates a pulsed 12 volts on output pin 49a when there is a path to ground by selecting a left or right turn signal switch position thru the associated turn signal lights. The pulsed voltage from flasher output 49a is tied to pin 49a of the hazard switch and the input pin 49a of the turn signal switch. Selecting left or right on the turn signal switch will flash the associated front and rear turn signal and flash the associated tach turn signal indicator.

Check the following:
With ignition on, select left or right switch position of the turn signal switch.

listen for the clicking of the flasher relay.
IF you hear NO clicking then perform the following tests to isolate where the open connection is in the turn signal circuit.
Test for switched 12 volts at the output of fuse 11.
If NO switched 12 volts at output of fuse 11, check input to fuse 11 and fuse 12. (fuse 12 input is hard linked to fuse 11 input)
If NO switched 12 volts at input to fuse 11 or 12 then check for switched 12 volts at output pin 15 of ignition switch. (It should be noted that there is a bulkhead connector T6f that is located under the instrument panel that connects the switched 12 volts between the ignition switch and fuse 12/fuse 11.

If YES you have switched 12 volts at the output of fuse 11, check for switched 12 volts at input pin 15 of hazard switch
If YES you have switched 12 volts at the input pin 15 of hazard switch, check for switched 12 volts at the output pin 49 of the hazard switch.
If YES you have switched 12 volts at the output pin 49 of the hazard switch, check for switched 12 volts at input pin 49 of flasher. (this connection is already verified when you tested the hazard switch)
If YES you have switched 12 volts at the input pin 49 of flasher, but the signal lights are still not working, shut off the ignition, disconnect the battery ground wire and perform a continuity test from pin 49a of the flasher relay connector and the turn signal switch input pin 49a. you are looking for very low resistance, if you have a high resistance check connections and bulkhead connectors T6e below instrument panel and t1f behind instrument panel.
If the resistance is low or close to zero then perform a continuity test on the turn signal switch 49a to 49L and 49R, select left turn switch position for testing 49L and right switch position for 49R.

The schematics show that there are bulkhead connectors that are used to connect different sections of the wiring harnesses. so when you find a missing voltage or a high resistance you will need to locate any bulkhead connectors in the failed area to verify the connections.

[911pby]

Pat
Thank you for your most generous and thoughtful post!!
I will follow the diagnostic procedure you've recommended -- thanks again.
Jeff

[fintstone]

Originally Posted by 911pby

Flintstone, you said "the hazard lights are powered separately."

Can you help me understand? I saw a previous thread where someone had a problem similar to mine and you advised: "…your flasher relay is most likely good and so is your turn signal switch. You are probably just not getting switched power to pin 49 when you turn on the key. Your problem is probably fuse 11…"

Is this what you meant?

Sorry to be so thick-headed about this, I'm on the steep side of the learning curve when it comes to electricity, but I'm working on it.

Jeff

Yes, more or less. Generally, with the conditions you describe, the flasher works and all the bulbs are good. When you turn the key on, you should have voltage on fuse 11 (You will probably not have brake lights also if this is your problem). I generally measure both sides of 11 to ensure the fuse is good and make sure the wire connections are tight and not corroded. If you have it there, next check at the flasher relay...much as Targa80 describes. I then check pin 49 of the flasher for 12 volts (with ignition on) and pin 31 for ground. If those are there, then your wiring to your turn signal switch are likely swapped or disconnected. You can generally sort those out by wire color.