Bronco 4WD issues

ISLHOPR

MEMBER
1993 FORD BRONCO
5.9L
V8
4WD
AUTOMATIC
165,000 MILES

Just got a 93 bronco, Tried to use 4wd - no lights, but does click on pushing buttons. Went underneath vehicle hit transfer case with hammer. Seemed it worked where I heard the function and got the 4wd lights, pushed the low button in neutral with brakes pedal pushed to test and no light on low, and the 4wd lights went off. Was able to try again got 4wd light, but again both lights went off when I pushed the low, then both failed again. Purchased new transfer case motor, upon installing the motor, when I turned the key on the 4wd was lit already, and still the low light never did come on, though the 4wd light will now not go away, even though the bronco is not in 4wd lol ! Tired backing up, as suggested but still lit. Went underneath and turned transaxle. It will turn freely to a point, buts starts to bind after about 1/4 turn or so, confused. Plz help

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Hi and thanks for using 2carpros. Com

There could be a few issues. The switch itself could be bad, the control module, or even a ground. Take a look through this diagnostic test. Note that the module has the ability to self check. I believe it's the 3rd step down when it discusses that. I attached a picture to help you locate the module. It is actually in the vehicle behind the right kick panel. The self test is what I want you to perform.

Try these tests and let me know what you find.

Electric Shift Operations

If the system operates improperly, or will not operate at all, a problem
could exist in a control switch, the electronic control module, the speed
sensor, the electric shift motor, the electro-magnetic clutch assembly,
neutral safety switch or the interconnecting wiring.

Use the following guidelines and test procedures to assist in locating the
cause of a problem.

Circuit Protection

The battery feed circuit, through a circuit breaker, provides memory
capability for the electronic control module.

Ignition RUN feed circuit, through a fuse, provide power for the switches
and the electric shift motor.

The circuit provides power for nighttime illumination of the switches
located in the instrument panel.

Control Module Self-Test

The electronic control module has a diagnostic capability of its own
circuitry. The self-test procedure is as follows:

1. Remove the five-wire connector and the eight-wire connector from the bottom of the electronic control module.

2. Turn the ignition switch to the RUN position.

3. Activate the self-test switch located on the module and note the result:

A flashing indicator lamp (approximately one flash per second) indicates that the control module is functioning properly.

A steady indicator lamp indicates that the control module is inoperative and must be replaced.

See Pic 1

Control Module Circuits

There are three wiring harnesses connected to the electronic control
module: the eight-wire pigtail harness connector; the five-wire harness
connector; and the eight-wire harness connector.

To check the integrity of these circuits, disconnect the harnesses from the Electronic Control Module and perform the following checks.

Let me know what happens.

Take care,
Joe

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