'04 Wrangler Starter Doesn't Crank All The Time

[Jerry9254]

PROBLEM: I have a 2004 Wrangler X (4.0L L6 OHV 12V) with manual transmission. My starter doesn’t crank all the time.

SYMPTOM: When the starter does crank the engine turns over normally (no strain or unusual sounds). When the starter doesn’t crank I can sometimes turn the ignition key several times and get the engine started. “Several times” can range from a few turns of the key to over a dozen. Sometimes the starter doesn't crank att all till I come back another day. Regardless of what the starter does/doesn’t do I always get power to the dash gauges and stereo.

TROUBLESHOOTING PERFORMED SO FAR:

1) Battery. I have a two-year old AutoCraft 34FT-2 with 800 CCA. The terminal connections are free of corrosion and firmly attached. I have continuity between the negative battery terminal and the frame. The battery’s resting voltage is 12V, and 10.3V when the key is in the start position. I’m calling the battery good.

2) Steering column. I removed the lock cylinder, ignition switch actuator, and ignition switch. I observed no broken parts overall. The lock cylinder functions properly. The ignition switch actuator is intact (including the pin assembly and adjacent metals arms) and functions smoothly. The starter switch appears visually intact; however, I have not been able to find a detailed pin-out in order to conduct continuity checks. Upon reassembly of the steering column the vehicle started with no issue. I’m calling the lock cylinder and ignition switch actuator good. I can’t confirm that there isn’t an intermittent connection in the ignition switch.

3) Starter relay. I removed the starter relay from the Power Distribution Center under the hood. I had continuity between relay terminals 87A and 30, and no continuity between relay terminals 87 and 30. I had 76.2 ohms resistance between relay terminals 85 and 86. When I applied battery voltage to relay terminals 85 & 86 I had continuity between relay terminals 87 and 30, and no continuity between relay terminals 87A and 30. I also confirmed that I had continuity between the cavity for starter relay terminal 87 and the starter solenoid. I’m calling the starter relay good.

4) Starter. I removed the starter to check the starter solenoid. The starter solenoid has continuity between the solenoid terminal & solenoid field coil, and between the solenoid terminal & solenoid case. Additionally, when I’ve had the no-crank condition I’ve lightly tapped the starter with a rubber mallet with no change in symptoms. I’m calling the starter good.

PATH FORWARD:

1) I could not confirm that the ignition switch is 100% good, but for now I’m going to continue on. If I can’t find anything blatantly broken, then the ignition switch is easy enough and inexpensive enough to replace just to be sure.

2) Next I’m going to check the clutch pedal position switch. I had to stop troubleshooting due to weather (My Jeep sits at the curb...I'm a victim of a packed garage).

Does anyone have any recommendations on what else to check that might be responsible for my symptoms?

 

[Chris]

1) Battery. I have a two-year old AutoCraft 34FT-2 with 800 CCA. The terminal connections are free of corrosion and firmly attached. I have continuity between the negative battery terminal and the frame. The battery’s resting voltage is 12V, and 10.3V when the key is in the start position. I’m calling the battery good.

Sorry, that's not enough to call the battery good. To rule the battery out you need to have it load tested by your local auto part store or Batteries Plus. Either will do it for free, and while I understand this is simple, it's something that absolutely must be ruled out. DO NOT overlook Occam's Razor.

Also, what do the battery terminals look like condition wise? Don't overlook that either.

2) Steering column. I removed the lock cylinder, ignition switch actuator, and ignition switch. I observed no broken parts overall. The lock cylinder functions properly. The ignition switch actuator is intact (including the pin assembly and adjacent metals arms) and functions smoothly. The starter switch appears visually intact; however, I have not been able to find a detailed pin-out in order to conduct continuity checks. Upon reassembly of the steering column the vehicle started with no issue. I’m calling the lock cylinder and ignition switch actuator good. I can’t confirm that there isn’t an intermittent connection in the ignition switch.

You can find detailed pin outs in the wiring diagrams here: Jeep Wrangler TJ Factory Service Manuals (FSM) & Technical Documentation

It could be your ignition pin actuator, which is a very common point of failure for TJs.

4) Starter. I removed the starter to check the starter solenoid. The starter solenoid has continuity between the solenoid terminal & solenoid field coil, and between the solenoid terminal & solenoid case. Additionally, when I’ve had the no-crank condition I’ve lightly tapped the starter with a rubber mallet with no change in symptoms. I’m calling the starter good.

I doubt it's the starter. It sounds electrical related to me.

 

[Jerry9254]

First off, thank you for the TJ FSM. That’s a valuable reference!

Regarding your comment on the battery and load testing, I will get the battery tested to confirm its state. Just a good idea to know where it stands.

Regarding your question on the battery terminals, when all this started they were brown with dirt and “terminal grease” in order to seal out moisture. There was no visible corrosion. During troubleshooting I removed and cleaned the contact surfaces of the battery terminals and the cable ends.

Regarding your comment on the ignition switch wiring diagrams in the TJ FSM, I didn’t see a schematic for the internals of the switch. On page 1133 of the PDF I did see the reference to a schematic, and I saw pin labeling on pages 1947 and 2152 of the PDF.

Regarding the ignition pin actuator, it is intact.

ADDITIONAL TROUBLESHOOTING:

1) Clutch Safety Switch. This weekend I was able to get in some more time troubleshooting. I separated a connector leading to the clutch pedal position switch and checked for continuity with the pedal pressed down. As the pedal cycles from 'released' to 'depressed' I should have seen a transition from 'no-continuity' to 'continuity'. Instead I read intermittent continuity with the pedal depressed, despite repetitive cycling of the pedal. In order to remove the clutch pedal position switch from the circuit, I installed a fuse into the position #20 in the fuse box to “simulate” an automatic transmission and bypass the safety—the Jeep started right up. Given that it started i'm caling the ignition switch good.

Is there anything else you recommend I check prior to replacing the clutch master cylinder?

 

[Jerry9254]

For anyone considering replacing the clutch master cylinder to remedy a failed clutch pedal position switch, here's some info you need to know before going to the store. The Service Manual for an '04 TJ says that for a failed clutch pedal position switch you have to replace the entire master cylinder (screenshot of passage from the manual below)

However, reading this post in this forum pointed me to Dustin's YouTube video. In the video, Dustin clarifies that the clutch pedal position switch can be serviced separately. Following Dustin's guidance I pulled and tested my clutch pedal position switch--it's broken. I'm going to order a new one, get it installed, and *hopefully* I'll be able to post that everything is fixed.

 

[Jerry9254]

Switch is in, Jeep is running again!

 

[toximus]

The battery’s resting voltage is 12V, and 10.3V when the key is in the start position. I’m calling the battery good.

You should probably be seeing closer to 13-14v charged, 12v running. I'm not sure what the cut off is at, but 10v is low for some systems.