No crank, no start, but problem solved (still no idea why)

gxgre

New Member
Joined
Jul 29, 2022
Messages
2
Location
connecticut
Long story short, on an 05 TJ 4.0 a/t, no crank with key, crank but no start if jumping the solenoid. No reverse lights. Ignition actuator OK. Transmission Range Sensor was the likely suspect, but before opening up transmission, I tried putting a fuse in #20 (which I guess works on a manual with a bad neutral safety/clutch switch). That didn't work, but #19 was also empty and for some reason putting a fuse in it did the trick. I can't find anything in the forums or the service manual that would explain this. Anyone?
 
I had no backup lights & a host of seemingly unrelated problems that tied back to a fuse (not #19 though), but was primarily caused by a number of wires shorted together above the transmission. Reverse lights, neutral safety, TCC lockup, maybe something else I don't recall. The easiest thing to troubleshoot here is the backup lights, I would go down that path and see what you uncover along the way. Maybe it's unrelated, but I'm going to wildly predict that it is 100% related.

Just don't be like Bill who posted once and then never came back. Also, fill out your profile so we know about your jeep your favorite color.
 
On my 2005 TJ Unlimited Rubicon with the manual transmission, fuse block positions 19 and 20 only have one terminal in them (switched 12V). The other terminal is empty. If yours is the same (missing one terminal), your fix was just coincidental. It's not possible for a fuse only connected on one side to make a difference.

I had some really weird, non-repetitive, issues with my ignition, including not starting, and I eventually replaced both the ignition switch and the ignition actuator to solve it.
 
I don't know who Bill is, but I won't be like him.

It turned out that the fuse was one of two ways that an aftermarket alarm system could be deactivated. I wasn't aware that there was an alarm onboard until I noticed a black box tucked up under the dash called a Hornet. Quick consult with Mr. Google showed me how the thing could be overriden; whoever installed it put in the "valet button" as well as this emergency override in the spare on the fuse panel. I still don't know what turned the alarm on in the first place, and the previous owner didn't k now it was there either, but Mr Google was also kind enough to provide a wiring diagram showing how to disconnect the starter circuit completely, and it is now officially disconnected.
 
  • Like
Reactions: Macrosill