Ok so here is the issue. Every now and then, about once or twice a month, my 1997 jeep grand cherokee won't start. When this happens, my battery is being drained by something. I've often heard a clicking coming from my interior fuse/relay compartment under the dash. Sometimes a car will jump start it but I've had to get additional voltage from a jump box sometimes. I've also seen my indicator saying that I have a rear lamp failure at times when this issue happens. I am not leaving anything on in my vehicle. I have had mu battery tested twice and it is good and my starter ispractically brand new with no issues. It also seems like this happens when it is raining alot outside, I don't know if that is just by coincidence or not. Has anyone had any issues like this or any advice?

 

Welcome to CF!

You're going to have to do a battery draw test to see what is draining your battery. There are several posts here that you can search for, but basically you have to put an ammeter between the positive battery post and the cable end to see what the draw is. With the key off, you shouldn't have more than 0.75 amps. That's about what the radio and PCM memory draws. If there's more, start pulling fuses until you find it. If that doesn't do it, disconnect the alternator.

The raining part has me curious. Look for a frayed section of wiring that is corroded and shorting out when wet. Look under the battery tray or the bottom of the main fuse/relay box under the hood.

 

I have had this problem with my 2021 Grand Cherokee. Every now and then I try starting the engine and the dash lights up but starter doesn’t crank. The battery is new and fully charged, and jump starting does not work. The Jeep service dept couldn’t figure it out, but confirmed it was not the battery. A guy from the towing service who said he was also an auto mechanic said he had seen the problem several times, and was most likely that there was condensation, or even rust, inside the “tube” of the starter that was preventing a connection with the flywheel (I’m not a car guy, just relaying what he said). Essentially he said that undercarriages on modern SUV’s are so encased that they don’t allow condensation to be released (hence your problem occurring intermittently, esp after it rains a lot). Replacing the starter will address the problem, but only for awhile, since it is a design flaw. The starter tube needs to have a drain hole to allow moisture to escape, or else moisture and/or rust will eventually cause the connection issue to recur. My car is at the dealer now being looked at, so I may learn more and come back to thi# forum if I do. Hope this was helpful.

 

To troubleshoot your 1997 Jeep Grand Cherokee's intermittent starting and battery drain issues:

1. Perform a parasitic drain test to check for excessive current draw.
2. Investigate the clicking relay in the fuse box, which might be failing.
3. Check for moisture intrusion, especially around the fuse box and dash during rain.
4. Inspect the rear lamp circuit for shorts or corrosion, as it triggers a warning.
5. Ensure all ground connections are clean and secure.
6. Inspect the ignition switch for potential faults.

These steps should help identify and resolve the electrical problem.