Try the library and get a Chilton's repair manual for 73 Plymouths.
A 1973 Plymouth Roadrunner Satellite
The Horn Relay for a 1971 Plymouth satellite is in the fusebox driverside behind brake pedal it is part of the box and it is possible to replace it with any standard relay
try yearone.com or manciniracing.com
Try the library and get a chiltons manual for your car.
On a 1973 Plymouth Fury III, the tail light relay is typically located under the dashboard, near the steering column or the driver's side kick panel. It's often housed in a relay box or mounted directly to the firewall. For precise identification, consulting the vehicle's service manual or wiring diagram can be helpful.
The cars were the same other than the fact that they had different options for the interior and other small details. In fact it is not at all hard to take one of those cars and transform them into the other one.
The bumpers for a 1972 Plymouth will fit a 1973 Plymouth duster with a little fabrication.
Her 1973 Plymouth Roadrunner Satellite never had a nickname. Her 1980 Jeep Cj-5 was nicknamed Dixie.
1973 Chevy pu wireing diagram
They should be interchangeable
http://www.mustangmonthly.com/ or http://www.mustang123.com/Downloadable wiring diagrams for 1964-1973 mustangs are available at:http://www.themustangshop.com/resources.cfm
http://www.mustangmonthly.com/ or http://www.mustang123.com/Downloadable wiring diagrams for 1964-1973 mustangs are available at:http://www.themustangshop.com/resources.cfm