starter wont stop running

Ok I have a 1990 bronco. 351w. The problem I used to have was every now and then when I turned the truck off the starter wouldn't stop. Then it never would and I would disconnect the battery. I replaced the starter solenoid and the ignition switch and the problem went away. But it only worked for 3 turn ons. Now it's back to whenever I connect the battery the starter comes on even with no key. When I turn the key the truck turns on but the starter is still running.

yo B,

With Key OFF, Check the R/LB wire at starter relay on inner fender for battery voltage;

If you have batty voltage thee; suspect ignition switch & test for voltage @ Ign sw

Try this Ignition Switch Pin-Out Diagram & Continuity Testing (Logic Tables in 87-91 (from Factory Manual and the Ford Electrical & Vacuum Troubleshooting Manual (EVTM)

Source: by Broncobill78 (Dave) athttp://broncozone.com/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=6659

Wiring Diagram for your 90 Bronco

http://www.revbase.com/BBBMotor/Wd/DownloadPdf?id=17413

or Ignition Actuator Rod (jiggle the rod by reaching beneath column

R/LB wire from your ignition switch through the Park/Neutral Safety Switch (NSS)/Manual Lever Position Sensor (MLPS), Or clutch safety switch on a manual trans, or NSS/MLPS with an AOD/E4OD, to the starter relay and the on to the starter solenoid (if equipped) and starter. Check this wire for

Next, check your upper ignition actuator. Find the ignition rod (on top of the column, running from the steering wheel down to the ignition switch at the base of the column) and make sure it's moving back and forth when you turn the key, through all positions. If it is, your upper actuator is probably not the problem.

Lastly, check your ignition switch (again, at the base of the column). Manually push the switch back and forth through the different positions. Push it all the way forward (or down) and see if it will engage the starter. If it does, then your ignition rod is probably bent, which can be remedied quite easily.

yo, If you have some knowledge about testing the system with Battery disconnected and starter relay Cable to starter disconnected; do that to avoid starter damage, etc.

Relay pics in a 90 5.8

Source: by ElKabong (Ken, El Kabong) at http://www.supermotors.net/vehicles/registry/15781/57039



Red/LB wire is on top; can be pulled straight off

With batty disconnected and test relay; if you want to be safe disconnect all large cables on both side of relay as well as Red/LB wire; check for continuity between both large posts; if 0 OHMs, relay is stuck closed

yo In response to you PM Question;

Red/Light Blue is a Red wire with a light Blue tracer on it;

it is the path for battery voltage from ignition switch to starter relay; it provides power to energize the relay thus making the starter run as long as the Ignition Switch is held in START Position.

I checked the starter solenoid it reads 0. But I know the starter solenoid is bad. When I put a new one in it goes bad. Idk what is making them to go bad

yo,

ok, you are referring to the relay on passenger side inner fender?

As shown in the pic I posted in previous reply?

Some aftermarket relays are inferior to Ford Motorcraft.

Here is one comment in my Defective parts Listing here; http://broncozone.com/topic/22216-starter-went-start-now-cant-stop/?&pid=116055&do=findComment&comment=116055

"Well folks it was the starter (RELAY) Solenoid. Third one in 5 days"; by scubachris

18 September 2011"

The internal terminal weld themselves together, thus providing voltage and current flow to starter all the time

Ok so I replaced the starter solenoid and the ignition switch. Our whatever that piece is on the steering column.

yo,

Sorry, had to go out and left PC on; can you check for voltage on the Red/Lt Blue wire along the path from IGN Switch to starter relay?

I'm getting 14 vlots from that wire

But when I go from the wire to ground I'm getting 0

YO; because you are getting 14 volts from that wire..

I assume it is that Red/Lt BLue wire; then your Ne ignition switch is now the issue with key in off, no voltage should flow to the Red/LtBlue.

Doe the KEY Cylinder feel loose?

Hey broncoboy,

let me see if I understand.  You are measuring 12 to 14 volts from the red/lb wire?  The wire that pulls off the starter solenoid.

Are you measuring that voltage with your key turned off?

Are you using a multimeter with the red probe in the wire, and the black probe on a ground?

You have voltage there with the key turned to the "off" position.   

If yes then there is a short in your ignition switch, or the actuator rod from the tumbler ( where you put the key in the ignition) to the starter switch is stuck in the start position

OR

There are wires shorted at or going to the starter switch that close the circuit to that red/ltbl wire. 

If you have voltage with the key off and in your pocket, find the starter switch on the top of the steering column near the base, under the dash.

Dissconnect the wires going to that switch.

If you still have voltage to the red/ltbl wire you have a short somewhere in that wiring.  Nothing but diligent searching will solve that.

If you have no voltage to the red/ltbl wire the starter switch is shorted

OR it is misadjusted

OR it is bound by the actuator rod.

Get back to us and we will see what the next step is.

Good Luck

It may not occur in this instance, but i had the same problem on my 88 and it turned out to be a bad ground, hope you find a fix.

Thanks yall. I ended up replacing the ignition switch. I looked at the old one and found out that to pieces had welded themselves together.

Glad you found the problem, and thanks for reporting back.

Good Luck