71 turn signal function

[inaminit]

Trying to diagnose a turn signal malfunction on a 71. First I studied a 74 wiring diagram which uses the current flow format. Not useful, different terminal numbers, etc. Then I studied a 72 line diagram in color-good way to get a headache trying to trace each line.
So, I am asking for some direction-is there anywhere a good discussion on how a longhood turn signal switch works? Actually how does the whole system work; turn switch, flasher relay, and emergency switch?
Thanks in advance for any help

[E Sully]

I can say it is a bit of a twisted system. I'll try and give a few details when I have time.

[E Sully]

It's an interesting question. Let's look into it, it's a bit busy in the wiring diagram. Sit back and try not to get car sick.
With the key on the turn signals power start at the Ignition Switch, terminal 15 Rd/Bk. Power travels to bridged Fuse's 7 and 8. From Fuse 8 Grn/Rd, power then travels along the to the Emergency Flasher, terminal 15. When the Emergency Flasher Switch is off, it travels through to Terminal 49. From the Emergency Switch terminal 49 Rd/Wh power travels along the to the Flasher Module, Terminal 49. The Flasher Module pulses the power to Terminal 49a. From 49a the power travels on the Bk/Grn/Wh wire to back to the Emergency Flasher Switch Terminal 49a. There it piggy backs another Bk/Grn/Wh wire to the Turn Signal Switch terminal 49a. The power will then travel to either 49L Bk/Wh, or 49R Bk/Grn when the directional switch is used.
It doesn't get simpler from this point.
When the Turn Signal Switch is used, power will travel along either the Blk/Wh for left, or Bk/Grn for right. It then splits into 4 Bk/Grn wire paths. One path is to the indicator bulb in the tachometer gauge. Another path is to Fuse block. From the fuse block positions 9 and 10, it travels to the rear indicator lamps, and back to the Emergency Switch terminals 30 L and R. From the fused side of the terminal block, the power travels fuse protected to the front turn signals.
I find it interesting most of the turn signal wiring is protected by fuse 8, and the front lamps are additionally protected by fuses 9 and 10. You have to realize, the Flasher module does not activate until the directional stalk is put in the left or right position, which completes the circuit to ground through the lamps. At this time, the indicator lamps are energized by the Flasher Module pulsing their ground with the Bl/Wh wire on terminal KBL (C on later diagrams).

[deemsriddle]

I keep these on all my cars. They are laminated well and hold up.

https://www.ebay.com/itm/320354022851

[E Sully]

It's a little easier to follow when you eliminate some of the wiring.
The Emergency Flasher (33)
Fuse 2 Rd/Bk is for the Emergency Flasher module, pin 30. It always has battery power. It does not come into play until the switch is pushed. Once pushed power from fuse 2 Rd/Bk goes to the flasher relay pin 49. It then follows the path as previously noted to the Flasher relay, and back on Bk/Grn/Wh 49a on the Emergency flasher module.
The Emergency flasher module now closes the contacts from 49a across terminals L and R, activating the flasher relay when pushed by completing the circuit to ground through all 4 signal lamps. The lamp in the Emergency flasher module also blinks by completing it's circuit to ground on terminal 31. It's that little circle with a x on the right of the module in the diagram.
The KBL terminal (C on later diagrams), Bl/Wh, makes the indicator lamps flash by completing the circuit to ground on both lamps now, as opposed to the directional signal which only activated one or the other.

[inaminit]

Thank you very much Ed-your explanation is very clear.
I hope that this will come up in a search when someone else has a turn signal question.

[E Sully]

Just because, here's one for a '69.