Originally Posted by j33pm4n
I purchased a 1999 Jeep Cherokee Sport 4.0L 6 cylinder in December. The Jeep normally runs fine but, on occasion, the engine will not turn over when the ignition key is turned. When the key is turned the starter relay clicks but the solenoid does not activate. After a delay and several attempts to start the problem will dissappear and the car will start normally.
Steps taken so far
The first step I took was to replace the starter (including the solenoid) with a remanufactured part from NAPA. The battery was an economy type from Walmart so I also replaced with a higher rated Bosch replacement.
Result - The car started when job completed but two days later refused to turn over. After about 6 hours tried again and the car started.
Used a voltmeter to check voltage to solenoid when the ignition key was turned but the engine did not start. No voltage indicated. Reseated the wire connection on solenoid and the engine started when the key was turned. Replaced the OEM wire connector with an in line butt connector from Radio Shack and insulated with tape. Solenoid did not activate when key was turned for the first time (but starter relay clicked). On second turn solenoid engaged and car started.
Uncoupled original manufacturer four wire connector next to the battery that brown wire to solenoid passes thru. Inspected contacts and found brown wire contact was depressed compared with other connectors. Used small screwdriver to realign contact. Used contact cleaner and Q-tip to clean all plug contacts. Reconnected plug and turned ignition key - engine started first time.
Four hours after cleaning connector in step 3, engine would not start. Uncoupled connector and used voltmeter to check for voltage when ignition key turned - no voltage shown at brown wire but starter relay clicked. Swapped starter relay for AC clutch relay (same part number) and tried key again. Relay clicked but no voltage shown on brown wire at 4 wire connector. Returned starter and AC clutch relay to original positions. Reconnected 4 wire connect. After a couple more tries engine started.
The problem appears to be somewhere between the starter relay and the 4 wire connector. However, the starter relay is housed in the black fuse box and there is no obvious way to get access to the connections to the relay. Has anyone else had this problem and solved it?
If it's an automatic, it could very well be the Neutral Safety Switch (NSS). the NSS can cause intermittent starting issues, particularly over time as it gets worse.
When mine was going bad, I would nudge the shifter a tad and the Jeep would start. Or, put it in neutral, then it would start.
Then one day I went out there to start it and it wouldn't start.
If it's the NSS, there are articles/threads on here about how to clean it up, and others are online if you do a Google search.