Circuit Identification

[Nutinbutford]

Good day all. Looking for some help please with identifying either the circuit ID or purpose for these two wires. The first one is a 3 wire, right behind the speedometer. The second picture is a pair of LT Green with a LT Gray hash, just past the radio.

The car was not equipped with the Convenience Group, so these may be redundant. As part of the restoration/cleanup I’m hoping to re enable the seat belt warning.

Thanks.
Rick

 

[midlife]

The second picture shows two leads for the AC system. The first picture shows two connectors: the bottom one is the radio; the upper one appears to be part of the emissions control?

 

[Steve McMahan]

Here is a copy of the 1973 Ford Mustang wiring diagrams. Look,this over and you should be able to answer your own question. If not, check back with us.

 

[Moderator73]

Here's a little more help
The First picture is of your connector C-1201. The Red/Yellow Hash wires are ckt# 640. The Brown/Orange Hash wire is ckt# 369. Both wires connect to your harness that connects to the EGR Control Module (the red box on the right side of this picture). Your connector in question C-1201 is where my finger is.

The second picture of your two Light Green/Purple Hash wires are ckt# 348 and connect to your A/C Switch Selector terminals of your heater control assembly. When you turn you dash selector switch to A/C mode it rotates the vacuum control valve which actuates this switch.

 

[Nutinbutford]

Thanks guys...your combined follow up has been very helpful. The car doesn't have A/C so the pair of Light Green/Purple Hash wires are redundant. No such EGR Control Module either. The circuit panel on this car also has the 6 connector/4 pin connector for the Convenience Group seat back warning.

On to chasing down ckt 520, seat belt warning. First challenge will be that a PO changed the front seat belt retractors to something other than factory so no C-409 or C-413.