Hello all, I have a '97 Ranger that apparently has a short of some sort somewhere. I was told to disconnect the positive battery cable then put a test light between the cable clamp and the positive post. The light came on as strong as if I put the test light directly to each post of the battery. I then went through the fuse box and removed fuses one at a time until the light went out. The fuse that did it is listed as the "IP Fuse panel". I know very little about electrical issues and I certainly don't know what IP fuse panel means or does. Does this make any sense to anyone? The fuse is a 50 amp so I don't know if it is there for an individual curcuit or is a main fuse of some sort.

Thanks in advance!
Wayne

 

It reads like that 50amp fuse powers the Cab Fuse box, I/P = instrument panel

Fuse box in the engine bay is called Battery Junction box, it feeds power to the Cab Fuse box.
Cab fuse box feeds power to most of the cab devices

So leave that 50amp fuse in place then move to Cab and start pulling fuse and watch the test light.

Just as a heads up, batteries can self drain, have you disconnected battery over night and does it still start engine the next morning?

1997 Ranger should have a Battery Saver Relay, it is behind the Radio.
This relay prevents most shorts, or left on lights, from draining the battery.
Battery Saver Relay doesn't shut down power when key is turned off, it waits approx. 20 to 30 min. after key is out and doors are closed.

You really need an AMP meter connected like test light is now.
Because battery is ALWAYS being drained, just a low amp drain for radio pre-sets, computer memory, and wireless key fob detection.

Your bright test light means there is a larger drain, but GEM module will be on and other electrics until Battery Saver Relay cuts power to them.
So I would leave key out close the doors and wait 30mins to see if test light dims, if it doesn't then I would look at Battery Saver Relay as being bad first.

With amp meter hooked up a working system will draw .03-.07 amps after battery saver relay cuts power.

This thread has 1997 fuse box layouts: Ranger: the heater fan is not working..blower works

Fuse 28 GEM system seems to also be battery saver circuit, try pulling it out and see what test light does

 

Thanks Ron, I didn't even realize there were two fuse boxes and still don't understand why. I think this truck has been owned by a teenager or someone young and stupid. There are exposed speaker wires leading to behind the seat and the warning signal doesn't work for the key (when left in, engine off). The interior light will not go out so I just removed the bulb. The seat belts have the wires unplugged and when I turn on the headlights or parking lights the radio light goes out then comes back on. The warning signal does work for the lights when the engine is off and the door opened. I think I have a headache vehicle here. I will work with the cab fuse box today and see what I can come up with.

Thanks again,
Wayne

 

1997 uses a GEM(generic electric module) to control interior electrics, which is a mini computer to control everything electric except engine.
From keyless entry to wipers GEM runs it all.

So if the dome light stayed on with doors closed pulling out the bulb just shuts off that one bulb, if one of the door switches are the problem then GEM would still be drawing power because it still thinks door is open.

Ford sends out EVTMs(electric/vacuum troubleshooting manuals) to all dealers for each model and year for the Ford mechanics to use.

You can buy these sets on-line(ebay) and some are downloadable.
They are very detailed and specific.

1997 Ranger EVTM
They usually include all engine and transmission options for that model and year

These are not EVTM drawings, just general wiring diagrams for 1997 Ranger 3.0l:

 

Thanks Ron, I haven't gotten around to anything yet today but plan on checking the cab fuse box first. I'll get back with what I find if anything.

Thanks also for the links. I can see where they would be very helpful.

Wayne

 

Ron, I went through every fuse in the cab fuse box with the test light connected as mentioned before. The light never went out. I believe that if the 50 amp fuse controlling the cab fuse box goes out the problem is in the cab. What would you suggest next?

Also, even with the battery draining the truck worked fine for several starts. I charged the battery and it was reading 13+ volts yet when I went to crank it the solenoid clicked and the engine didn't turn one revolution. I also checked the battery a few weeks ago when this problem started and when running the meter showed 14+ volts so I figured the charging system was working.

Wayne

 

Yes, 14+ volts just after starting is correct, it should drop down to about 13.6v after a few minutes of driving, 14+ is reCharge, 13.6 is maintenance Charge less than 14v keeps battery charged but doesn't "cook it"

I don't have a detailed circuit diagram for your model and year so can't really say what else might be running off that 50amp fuse.
If wiring has been cut and spliced then that could be the drain on that circuit because they spliced in a wire to the 50amp wire and not a cab fused circuit.

If possible drop down the cab fuse box and look at 50 amp feed wire to see if it has been spliced

Often the Glove box light and/or hood up light can be the source of drains.

Check that ALL the parking lights and cargo light are working, a burned out bulb can short system causing a drain.