91 Mustang Switch Problems

[jmr91]

Hello friends I have been trying to fix my 91 mustang 5.0. I had posted a while back but I have done a little work and it still is kinda stumping me. I basicallyhave no power from the switch no radio no fuel pump nothing and no crank. The battery is good. When I came out to start working on it today I turned the key back to me and the radio and wipers came on when I moved it to start the engine would start to turn over but would not start then it just quit all together. I put a new key cylinder and a new switch on the column and still nothing not even with the key turned back to me. So I put the old key cylinder back in and turned it back to me and the radio came on from a min but I accidentally bumped the turn signal switch and it went back off and will not come back on. I feel like the problem is right here on the column but I'm not sure what else to look at or replace or if I'm completely wrong. Has anyone else had a problem like this

 

[mikestang63]

did you check the wiring coming off the ignition swtich on the column- not the igntion key but the plastic and pot metal switch under the dash on the column. The wires are prone to melting if the switch goes bad.

If not, get ready to start an easter egg hunt. Get a good DVM and test light and @jrichker for the wiring schematic.

 

[jmr91]

did you check the wiring coming off the ignition swtich on the column- not the igntion key but the plastic and pot metal switch under the dash on the column. The wires are prone to melting if the switch goes bad.

If not, get ready to start an easter egg hunt. Get a good DVM and test light and @jrichker for the wiring schematic.

I replaced the metal piece that had those odd torx screws it didn't look like the wires were damaged but I didn't really go over them as well as I should have. I did order a replacement wire harness that would replace that one but I haven't received it yet

 

[jrichker]

Diagrams courtesy of Tmoss & Stang&2birds

Ignition switch wiring

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/ Everyone should bookmark this site.

Complete computer, actuator & sensor wiring diagram for 91-93 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/91-93_5.0_EEC_Wiring_Diagram.gif

Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

Fuel, alternator, A/C and ignition wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

O2 sensor wiring harness
http://www.veryuseful.com/mustang/tech/engine/images/mustangO2Harness.gif

Vacuum diagram 89-93 Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg

HVAC vacuum diagram
http://www.veryuseful.com/mustang/tech/engine/images/Mustang_AC_heat_vacuum_controls.gif

TFI module differences & pin out
http://www.veryuseful.com/mustang/tech/engine/images/TFI_5.0_comparison.gif

Fuse box layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif

87-92 power window wiring
http://www.veryuseful.com/mustang/tech/engine/images/mustang87-92 PowerWindowWiring.gif

93 power window wiring
http://www.veryuseful.com/mustang/tech/engine/images/mustang93PowerWindows.gif

T5 Cutaway showing T5 internal parts
http://www.veryuseful.com/mustang/tech/engine/images/5_Speed_Cutaway_Illustrated.jpg

Visual comparison of the Ford Fuel Injectors, picture by TMoss:
http://www.veryuseful.com/mustang/tech/engine/images/Ford_Injector_Guide.jpg