Accessory/Diagnostic Switch


Red Light:

This is the Alternator Light

Blue Light:

This is the Computer Danognostic Code Light

Accessory Switch:

This is for Activating the codes in the computer

Computer Codes:

To check the Computer Codes, turn the ignition on do not run the engine
Turn the Acc Switch on, the codes will be displayed on the green light and flash three times for each code
The codes for each engine are different and are found on this web site, or click the link below
Fault Codes VP
Fault Codes VR
Even if you get a code 12 (clear code) always do the three sets of lights and make sure that there is not more after it
To clear the codes unplug the computer for 2 minutes

some codes are soft codes and just identify a problem and do not send the computer into limp home mode, an example of this is Code 48 on a VR, being the Cam Shaft Sensor, if you are running a VR Loom on a VP it does not have this sensor so will always flash this code and the light will come on when running, if you don’t want this just disconnect the feed wire at the ignition switch.

FORD Street Stock Fault Codes

FORD EF Fault Codes