What are these plugs?

[Wiser_Papa]

Newbie here. While I was replacing the brake master cylinder I noticed these wires running under it that need to be cleaned up. Can you tell me the purpose of the wires identified by the blue arrow, as well as the purpose and function of the big plug identified by the red arrow? What do those things do?

IMG_6956.jpeg

[jrusso07]

Reverse switch on the transmission. One side goes down to the switch and the other side comes back up to a connector that goes back to the lamps.

[drieseck]

Might help, see attached diagram.

68 wiring diagram.pdf

Red with Black are for your reverse switch (light). one set going to lamps (as per jrusso07), one set going to the switch mounted into the transmission.

Coupler looks to be for your starter harness and looks to have been overheated, cleaning that one up is a good idea.

[david premo]

They might be unplugged because the wrong switch or a bad switch in the transmission keeps the reverse light on 100% of the time.
Dave

[redroadster]

In the 60s-70s my neighbor and others hooked the reverse lites to a switch to flip on it meant - want to race & we are racing look out...I got pulled over in my 70 charger R/T 440 4sp they want to see if the reverse lites worked

[Wiser_Papa]

Well that was easy. I cleaned and plugged the reverse wires together and I now have a working reverse light! As for the starter harness, I most certainly need to clean that up.

[Wiser_Papa]

Ok now in the same area, against the inner fender wall, what is this thing and why is it hot, even though nothing is turned on? Is that normal?

IMG_6960.jpeg

[Stick]

That is the horn relay .... there must be a short somewhere... my guess would be in the horn button. The relay should only be energized (sending power to the horn) when you push the horn button, which completes the ground to the relay coil.


FYI The other similar (but larger) relay closer to the firewall is your headlight relay.

[Wiser_Papa]

That is the horn relay .... there must be a short somewhere... my guess would be in the horn button. The relay should only be energized (sending power to the horn) when you push the horn button, which completes the ground to the relay coil.


FYI The other similar (but larger) relay closer to the firewall is your headlight relay.

Perfect! Well chasing down the short in the horn circuit eliminates a parasitic drain right there!