Ugh, XJ wont turn over... sometimes?
 

My XJ has been acting strange for the past two weeks. It starts up normally most days, but then sometimes when I go to turn it over everything just dies electrically and I need to let it sit for a minute before trying again.

I've checked the battery cables and they are secure. Where should I look next? When it does turn over everything is normal which is most times. The starter is not giving any indication of falter.

Grounds can be the root cause of many electrical gremlins. Refreshing grounds is NEVER a bad idea, and the investment of your time in this procedure is always well worth it!

You can't tell much of anything by looking at ground connections!! You must remove, scrape, clean until shiny the cable/wire ends and whatever they bolt to. Be sure to remove all paint from any ground connections.

Start with the one on the back corner of the head, and where it attaches to the firewall, as it deteriorates over time and is an area that makes it susceptible to damage. Best to replace that woven cable with a #4 or #2 gauge cable. You can attach the one end to the intake manifold if you would like.

Next go over to the engine dipstick tube stud. Remove the nut and clean the wire ends and scrape the block until shiny at the stud. Reattach tightly.

If you are so inclined, add at least a #6 cable from the negative terminal of your battery to one of the bolts on your radiator support.

Everything electrical going dead is a common sign of some sort of bad connection to the battery. Be it the clamps or wires there is likely something wrong there. I went through that issue with two Cherokees so far. The circuit is breaking somehow.