Weird intermittent starter actuation

[Great_Big_Abyss]

So I have this intermittent problem with my truck that has creeped up in the last couple of days.

2006 Ranger, 4.0L SOHC, 5spd manual, 4x4, pretty much stock everything.

When the engine is running, if I put my foot on the brake, the starter engages the flywheel, just as if I'm turning the key to the 'start' position. When I release the brake pedal, it stops. Sometimes it will cut out the radio and flash my dash warning lights (as if the truck is actually being started), and sometimes it will just actuate the starter.

This is an intermittent problem. Sometimes it does it right after I've started the truck, sometimes it doesn't do it for 15 minutes. It could do it for 5 minutes (as long as my foot is on the brake). Or it may do it once or twice before stopping for a while.

It happens regardless of clutch position, whether or not the AC is being used, ventilation on/off.

I've checked the key position. The key is definitely at the 'on' position, and is not loose within the barrel.

So...any ideas as to what is going on?

 

[HAPPY+RANGER+GUY]

Do you have a wire bundle getting pinched or rubbed under there somewhere with the pedal movement?

Strange.

 

[HAPPY+RANGER+GUY]

When the engine is running, if I put my foot on the brake, the starter engages the flywheel, just as if I'm turning the key to the 'start' position. When I release the brake pedal, it stops.

Does the parking brake cause the same issue (thinking is doesn't).


Has the truck ever been in an accident?

 

[Great_Big_Abyss]

Does the parking brake cause the same issue (thinking is doesn't).


Has the truck ever been in an accident?

No and No.

 

[adsm08]

Test two things for me quick.

1) Unplug the brake light switch, see if the problem goes away.

2) Use a small piece of wire to jump power across the plug for the brake light switch and see if the starter kicks in.


I'm with Happy, sounds like something is rubbed in the wires, and either the brake lights are shorted to the starter trigger or the pedal arm is pinching something and completing a circuit that shouldn't exist, powering up the starter.

 

[RonD]

Does it do it with Key OFF?
If not then it is not an issue with brake light switch, it always has power.

Google: How To Install Replace Ignition Switch Ford Ranger 95-04

I know it is not 2006, but it will be similar.
Once you have removed the two panels you will be able to see under the dash better.

My guess is that some wires are shorting together since it is an intermittent issue, if it was crossed wires then it would be every time.
Push the brake pedal in and see what wires move

 

[Great_Big_Abyss]

ADSM and RonD. Thanks for the replies. I'll get to looking at it tomorrow sometime, and will post back with any potential results.

It does NOT do it with the ignition off.

 

[Great_Big_Abyss]

Sigh...intermittent problems. I let the truck sit over the weekend as I didn't have to go anywhere. I drove it to work and back yesterday, and drove it to work today. I did a mix of city and highway driving both days, and the problem seems to have disappeared. So...diagnosing it will be difficult now. Oh Well, at least it seems to have gone. last time it reared its ugly head and then disappeared, it was gone for a couple of years, so maybe it will be the same thing this time...I won't see it until 2015!

 

[HAPPY+RANGER+GUY]

intermittent wire circuits

Either you won't see it for a while or one day soon you'll see a ton of smoke billowing out from under there!

I hope it will not cause too much damage when you DO see it again.

 

[HAPPY+RANGER+GUY]

I guess what I'm trying to say is... You may want to look a little harder to possibly recreate and solve the issue. If you can locate the source of the trouble...or likely source of the trouble, you may prevent some property damage or possible injury to someone in the future. There are lots of things that can happen even when everything is working as it's suppose to. When you have intermittent circuits that exist when they shouldn't, really bad things can and do happen from time to time. Just something to think about.