[JCC1701]

When it doesn't start it behaves like a dead battery with one click at starter and then silence. Upon releasing key date/time are reset on display, lights are dim, and there is a clicking behind glove box. The clicking and dim lights remain until pressing brake pedal which seems to restore electrical. I try starting again and either repeat above steps or engine starts.

So far the engine stays running and Jeep drives like normal with just one exception where there seemed to be total electrical loss about a minute after starting but then immediately started up again. All power cables are clean and secure at battery, starter, alternator, etc. I am a touched confused and especially bewildered about the magic brake pedal...

Previously I had noticed the radio losing power momentarily during right turns out of driveways but nothing else was affected and it has only occurred 3 or 4 times over a few months. Most likely unrelated to primary problem described above, but since both problems feel power related I thought there may be a connection so worth mentioning.

I always seem to encounter the odd problems that takes forever to identify cause so any input, suggestions, and of course help would be immensely appreciated!

98 ZJ 5.9L

[JCC1701]

Just remembered, when lights are dim and clicking behind glove box the defrost button indicator lights up.

[BigE3]

Check all your battery connections thoroughly. Main one to check are the lead battery connections. They like to come loose. And twist your connectors by hand to see if they are loose on the posts.

[nlynd1978]

Check your batery ground and engine ground. Sounds like a partial short to me.

[MacK]

Originally Posted by JCC1701

When it doesn't start it behaves like a dead battery with one click at starter and then silence. Upon releasing key date/time are reset on display, lights are dim, and there is a clicking behind glove box. The clicking and dim lights remain until pressing brake pedal which seems to restore electrical. I try starting again and either repeat above steps or engine starts.

So far the engine stays running and Jeep drives like normal with just one exception where there seemed to be total electrical loss about a minute after starting but then immediately started up again. All power cables are clean and secure at battery, starter, alternator, etc. I am a touched confused and especially bewildered about the magic brake pedal...

Previously I had noticed the radio losing power momentarily during right turns out of driveways but nothing else was affected and it has only occurred 3 or 4 times over a few months. Most likely unrelated to primary problem described above, but since both problems feel power related I thought there may be a connection so worth mentioning.

I always seem to encounter the odd problems that takes forever to identify cause so any input, suggestions, and of course help would be immensely appreciated!

98 ZJ 5.9L

I had a 93 that did something similar, but the engine wouldn't run and when it did it ran poorly. But then sometimes it would run fine, but once you shut it off it was done. Not sure if this is even related, but mine had a bad computer in it. Just a suggestion though, I may be wrong. I got a new one at the junk yard for $50 and that Jeep ran great.

[JCC1701]

@nlynd1978: Battery connections were the first thing I checked, both clean and tight. Thanks for the suggestion though.

@ThomasMack: I had a 97 4.0 that sputtered occasionally and stalled twice which was the ECM but it never encountered full power outage which reset date/time and caused lights to dim. I still am keeping ECM in the back of mind but for no good reason am suspicious of the battery itself. Thinking is that if the battery shorts internally that would cause full power loss to electrical system.

[jp88]

I had a battery cause some similar issues to the ones you are having.

[basssolow5]

do you have those clamp-on type battery connections? meaning are they the kind that you just clamp onto the bare wire? if so replace those. ive had nothing but problems with the ones on my zj. im going to replace them when i get money.

[JrMechanic]

Just because they "look" clean and tight, doesn't mean they are. Remove them, clean them, and re tighten them. The problem you described is caused by a bad connection at the battery 99% of the time.

[JCC1701]

After several problem-free days I am ashamed to say I did not inspect the battery posts as closely as thought. While the neg was shiny a flashlight showed the pos looked as if spray painted black. Brushed them both up and back to business