Electrical system concerns that are due to diode failure may be serviced with an approved Ford service diode. Some electrical diodes used in early production vehicles are color coded for the purpose of size identification while others are stamped with a manufacture number. All Ford service diodes and current production diodes are identified by manufacture number.
ACTION If service is required, refer to the appropriate model/year Electrical and Vacuum Troubleshooting Manual (EVTM) to determine the size and location of the diode(s). Refer to the following Electrical Diode Application Chart for the correct service part number.
Electrical Diode Application Chart
Old Design Current Design Service Part Identification
(color gray) 1.0 Amp-200V
1N4003 Micro 1-Amp Diode - $1.19 -http://www.radioshack.com/product/index.jsp?productId=2036269
Some comments on this diode;
"Used 2 diodes wired parallel so that the surge protection would be a safe 30 amps. The diodes were used on an ignition supply cable to 3 headlight door relays. Took me about an hour to solder in and fabricate a harness but wow! Does it work great! You cannot buy a harness anymore for a 68 camaro headlight doors! Thanks Radio Shack!" by Jim the Tech