1971 2800CSA: Turn Signals & Hazards not working

[nobrakese28]

Hi, was hoping someone could point me in the right direction if this is a common issue. I am getting my 2800CSa (now a 5spd manual) back on the road and realized my turn signals do not function, that car was in dry storage for about 10 years. The headlights, brake lights, license plate lights, and side markers all work, just no turn signals or hazards, but the hazard switch does illuminate red when pressed. Fuse 7 is in powered which is labeled as: "stoplight, horn, backup-light, turn signal, auto-choke, warming lights, fuel and water temp. gauge, electrical fuel pump" in the factory fuse panel.

I probed what I believe is the flasher relay (located in the hood pop drop door cavity, to the right) and saw no power feeding it. From the schematic I believe power first flows through the hazard switch then to the flasher relay.

Facts:
Car is now a manual trans
Zenith carbs have been removed, so green/white and black/brown wires to chokes and temp switch are no longer connected (still have switched power)

Hoping it's just a connection that needs to be cleaned, but any help is appreciated.

Thanks,

Marco

 

[HB Chris]

Yes, the flasher box is mounted on right side of opening next to the column. I would think that it is your issue, the Wiring FAQ shows how to use a modern digital unit, it is very easy to convert.

 

[Catbert]

I have the same issue with my newly purchased 1975 Euro-spec CSi. SFDon was quick to point out that a common cause is a faulty emergency flasher switch-- either that or the relay, or both. So, upon receipt of a new emergency flasher switch and relay, I will hopefully have operational turn signals so I can drive my car!

 

[ScottAndrews]

In my experience the flasher switch has two failure modes. One common and the other not. First mode is that it fails to catch when pressed in. Don showed me a few days ago how to disassemble the switch and weak it so it stays in when pushed. The other mode is an internal short. The switch is somewhat complicated since it must power the turn signals when the ignition is in ACC/RUN, but it also must power the flashers with the ignition entirely off. This means the BATT and ACC buses both connect tot he switch. If there is an internal short, the switch can back feed the ACC bus and turn on accessories when the key is off. Weird ghost in the machine effect....

All that said, the lack of blinking is most likely either wiring, corrosion or a faulty blinker. If the switch stays in when pushed, and there are no ghostly things happening when the key is off, the switch is most likely fine.

 

[Catbert]

My emergency switch is lit red. It stays in when pushed. No spooky things happening. Just no flashing lights or working turn signals. Hopefully, a new switch and/or relay will solve the problem. As the Zen Masters says, "We'll see."

 

[ScottAndrews]

My emergency switch is lit red. It says in when pushed. No spooky things happening. Just no flashing lights or working turn signals. Hopefully, a new switch and/or relay will solve the problem. As the Zen Masters says, "We'll see."

Almost certainly the flasher unit then...

 

[jmackro]

I probed what I believe is the flasher relay (located in the hood pop drop door cavity, to the right) and saw no power feeding it. From the schematic I believe power first flows through the hazard switch then to the flasher relay.

I agree that electronic flasher units will solve a variety of turn signal / hazard light issues, But, if the existing flasher isn't getting power, then installing a new one isn't going to fix things. And yes, power to the flasher unit routes through the E-flasher switch, alternating between switched power for the turn signals when the engine is running and unswitched power for the hazards when the key is off.

So I like the idea attributed to SF Don in post #5, that the E-flasher switch could be the cause of no power to the flasher unit. That problem could either be internal to the switch, or how it's many wires are connected (if the factory plug-in connector looks un-molested, then the issue is probably internal).

Still, even once the flasher unit is receiving power, the lights may not flash if you retain the mechanical flasher unit. Those things are temperamental. They rely on a proper amount of current flowing through them to get them to flash and at a reasonable rate; wrong bulb wattage, corroded bulb sockets, tide levels, phase of the moon, etc. can throw them off. Electronic flashers are more forgiving.

 

[Catbert]

I agree that electronic flasher units will solve a variety of turn signal / hazard light issues, But, if the existing flasher isn't getting power, then installing a new one isn't going to fix things. And yes, power to the flasher unit routes through the E-flasher switch, alternating between switched power for the turn signals when the engine is running and unswitched power for the hazards when the key is off.

So I like the idea attributed to SF Don in post #5 that the E-flasher switch could be the cause of no power to the flasher unit. That problem could either be internal to the switch, or how it's many wires are connected (if the factory plug-in connector looks un-molested, then the issue is probably internal).

Still, even once the flasher unit is receiving power, the lights may not flash if you retain the mechanical flasher unit. Those things are temperamental. They rely on a proper amount of current flowing through them before they will flash; wrong bulb wattage, corroded bulb sockets, tide levels, phase of the moon, etc. can throw them off. Electronic flashers are more forgiving.

Good points and things to know should I have more troubleshooting to deal with.