Resolved Please help! (starting issue)

Ok I’m goina try to get all the relevant info out and hopefully someone knows what the golly gee whiz is up. I have had this 89 mustang 5.0 for a while now and has sat for maybe 8 years. It has an aftermarket security system(black widow, 2 button fob) in it that came with when I bought it. It’s a typical no crank no start sitch, however battery is new 13v charge, starter is new and jumps fine, new solenoid that also jumps fine, ignition switch works and all electrical on the car works. I have jumped the clutch safety switch with no luck I have basically narrowed it down to the wire providing my solenoid with 12 volts when the key is turned will not get 12v.. my brain is exploding and I’m bout to run a new wire and tie that in to the ignition but I wanted to see if anyone knows the proper fix for this? Never posted on a forum before for help so hopefully covered all the bases here, thnx in advance for the read!

Noobz347 said:

See if you can get a model number off of the alarm system. Look for a user manual online and "uninstall" the thing.

If it's been sitting for 8 years, there's no way in hell that I'd be cranking on it without draining and purging the fuel system.

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Yeah I been looking around around for some info on the thing but really don’t wana have to undo the mess they made in there with the wiring unless absolutely need to. “Uninstall” meaning completely remove from the wiring? And yeah iv drained the system and already pumped her with some new premium, no varnish for the old girl.

*update* just bypassed the alarm systems starter kill relay and still no 12v to the solenoid thinking may not even be the alarm system now

AeroCoupe said:

I would bet $100 they did a starter interrupt on the red/blue wire with the alarm install. Most likely didn’t with an external relay and the ground trigger from the alarm is keeping that wire from energizing.

You might want to back probe the red/blue wire at the ignition switch and see if you are getting g 12V there when cranking. If so then I stand by my opening statement of an alarm issue. If not then it’s the switch.

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There looks like there is an interrupt relay but I have just bypassed it hoping that was the issue but seems to still not have 12v to solenoid. I have tested the ignition switch as well using multimeter and get 12v coming out on the pink/white wire ever turn. Very puzzling for me

Omg…… I figured it out and incase anyone is having the same crazy issue I was having, it was the backup light harness under the car that plugs into the side of the transmission had somehow got the red jumper wire cut right off. That harness apparently prevents you from starting the car using the keys. Crazy crazy time finding that out so I hope my pain helps someone find this quick! Thanks for all the replies trying to help.