Jeep Cherokee

 Service Manual

Starting systems » Diagnosis and testing
Starter motor

Correct starter motor operation can be confirmed by performing the following free running bench test.

This test can only be performed with the starter motor removed from the vehicle. Refer to Starting System in the index of this service manual for the location of the proper starter motor specifications.

CAUTION: The 2.5L engine uses a permanent magnet starter. Permanent magnet starters are highly sensitive to hammering, shocks, external pressure and reverse polarity. This starter motor must never be clamped in a vise by the starter field frame. The starter should only be clamped by the mounting flange. Do not reverse the battery cable connections to this starter motor when testing. The permanent magnets may be damaged and the starter rendered unserviceable if it is subjected to any of these conditions.

STARTER MOTOR

(1) Remove the starter motor from the vehicle.

Refer to Starter Motor in the index of this service manual for the location of the proper starter motor removal and installation procedures.

(2) Mount the starter motor securely in a softjawed bench vise. The vise jaws should be clamped on the mounting flange of the starter motor. Never clamp on the starter motor by the field frame.

(3) Connect a suitable volt-ampere tester and a 12-volt battery to the starter motor in series, and set the ammeter to the 100 ampere scale. See the instructions provided by the manufacturer of the volt-ampere tester being used.

(4) Install a jumper wire from the solenoid terminal to the solenoid B(+) terminal stud. The starter motor should operate. If the starter motor fails to operate, replace the faulty starter motor.

(5) Adjust the carbon pile load of the tester to obtain the free running test voltage. Refer to Starting System in the index of this service manual for the location of the proper starter motor free running test voltage specifications.

(6) Note the reading on the ammeter and compare this reading to the free running test maximum amperage draw. Refer to Starting System in the index of this service manual for the location of the proper starter motor free running test maximum amperage draw specifications.

(7) If the ammeter reading exceeds the maximum amperage draw specification, replace the faulty starter motor.

STARTER SOLENOID

This test can only be performed with the starter motor removed from the vehicle.

(1) Remove the starter motor from the vehicle.

Refer to Starter Motor in the index of this service manual for the location of the proper starter motor removal and installation procedures.

(2) Disconnect the wire from the solenoid field coil terminal.

(3) Check for continuity between the solenoid terminal and the solenoid field coil terminal with a continuity tester (Fig. 11). There should be continuity. If OK, go to Step 4. If not OK, replace the faulty starter motor.

(4) Check for continuity between the solenoid terminal and the solenoid case (Fig. 12). There should be continuity. If not OK, replace the faulty starter motor.

Starting system

Starter motor noise - 2.5L engine

Starter motor

Starter relay