Hello,

I have a 99 ranger, 2.5 L. It keeps blowing fuse # 27 which controls the overdrive, backup lamps, transmission control switch, elec. shift, and pulse vaccum hub lock. I fave faund that the fuse blows anytime i put the truck into reverse or when i pass through reverse to go to drive. The fuse use to blow antime i towed anything but now it blows constantly. Any comments or suggestions are appreciated.....thanks........eric

 

I would say it has somthing to do with the trailer harness.Follow it back to where it splice's into the brake light harness take it apart and look for wire's toutching together.Or the harness wires may be exposed to the frame causing a short.This happened to me.

 

I read that the Transmission Ranger Sensor Switch is responsible for this problem. Just ordered one for my truck.

My reverse lights blow only when I put the car in drive or reverse.
My Overdrive switch in not working.
My windshield wipers intermittent wipe like they are psychotic, never the same amount of times.
My interior light stays on.
My door ajar light stays on.
My air conditioning blows hot.

Piece of crap car and nobody has answers that work to fix any of it.

 

did you find the issue? I'm having the same problem with my truck

 

It is time to take the truck to a qualified shop with basic electrical background. It does not take rocket science to find the cause, just a little solid electrical testing.