Engine 92 GT not starting from key

[bd8134]

A friend has bought a GT for his son for when he gets his license / permit.
Some parts were missing / broken but he also bought a 7-UP from me so he should be ok, just needs to replace the heater core at one point.

The car will start from the key. I can run a jumper from the battery+ to the starter solenoid coil terminal with key in run, it starts right up.

When the key is in run I get 12v on the red/green wire on the ignition coil, but when in start there is no voltage.
The gauges also go blank, no tach etc, also no voltage on fuse 18 during start if that is relevant.
The starter solenoid does energize and the starter does work if the thin red/blue wire is on the coil terminal, it just will not start because of no voltage at the coil.

The clutch pedal has to be buried into the firewall for the starter solenoid to work, wondering if that other circuit / contact on the clutch interlock switch is faulty which goes to the ecu.

The ignition switch has been replaced.

I have read through the a lot of the great notes from this site on no start etc but cannot find this symptom. I cannot remove the wiring plug from the distributor as it is rotated to close to the ac compressor.

 

[jrichker]

You have problems in the ignition switch wiring... I hope you have aa good DVM or Multimeter and know how to use it correctly.

Check the ignition switch wiring harness connector and you will find at least 1 wire that fails to have battery voltage on it in crank mode. The accessory power shuts off in crank mode, so use the diagram below to eliminate it from your testing sequence. The brown/pink wire in the ignition switch diagram below would be the best place to start.

Ignition switch wiring

Fuel, alternator, A/C and ignition wiring

 

[bd8134]

I have a nice Fluke DVM thank you. and I have the old ignition switch beside me but it believe "behaves" the same way as the new one in the car.
I have one lead of the meter on the BAT terminal of the switch, the other lead on 16 which would have the red/LT green wire going to the coil.
In run I have continuity, in start it is open circuit.
One lead on BAT the other on 262, this would be the brown/pink which connects to the red/LT green wire as above.
In run this is open circuit, in start I have continuity.
The red/LT green and brown/pink wires from the ignition switch are separate and are tapped up in the loom and disappear above the steering column.
Where is do these 2 wires join together, fuseable link on brown/pink wire?
Where does the fuseable link shown in your diagram on the red/LT green, located?

 

[jrichker]

What year car do you have? I have the wring diagrams for an 89 Mustang which may be useful.
PM me your email address and I will send you a complete Ford Factory 89 Mustang electrical diagram set. The zip file is 2.5 MB and is too big to fit through Stangnet's email gateway.

The plug shapes on the diagrams match the plug shapes on the actual plug. The diagram is divided up by the layout of the car. The first diagram is for the very front of the car, and it works its way to the rear of the car page by page.

They are in a zip file format to reduce the size of the package. If you don't have Windows 7 or Windows 8, or later, you’ll need WinZip or other Windows archive tool to extract them from the zip file.. See www.majorgeeks.com - Download Freeware and Shareware Computer Utilities for a free download.