Starting issue

I am having issues with my starter. Its a 98' 4.0L. I got the jeep about 6 months ago and when I got it the owner told me he sometimes had to jump the starter to get it to fire. He said he's replaced the starter before and it still does it. I put in the key and get all the lights gauges etc to work, go to turn it over and nothing. I have to go down and jump the solonoid on the starter with a screwdriver. When I do that it fires right up and stays running just fine. It will start every once in a while. I don't want to spend the cash on a starter if I don't have to. I'm thinking its possibly a bad ground on the motor or a bad power wire to the starter. Any other idea's?

Oh and to make things even better, today the jeep won't idle it just dies. The battery died the other day and I had to jump it. I guess the battery is still bad. I searched on here and found that if the battery doesn't have enough juice that it will screw with the computer and it will not let it idle. I will be getting a new battery tomorrow. If that doesn't fix it then I'll try a TPS first then I guess a CPS next. Hopefully the battery will fix that issue.

First, I'd look in the PDC for a Start Relay (I think ChryCo kept using them) and probably replace it. If the starter works when you jump the solenoid, then it's good, and it's got good power and ground. The start relay is supposed to send power to that little terminal when you turn the key to START - if it doesn't, it won't crank.

If that doesn't work, then the solenoid wire is probably toast - but check the relay first.

On the second issue, if the battery is low enough to want a charge all the time (not accepting a charge or just self-draining rather quickly,) then the alternator will lug enough (trying to make max power) that it might kill the engine at idle. That doesn't mean anything's wrong with the alternator - it's trying to do its job - it's just being overworked by a probably-failing battery.

If you really want to test the battery, do what I usually do - put it on the charger, and give it a full charge. Put it in the freezer for 30-45 minutes. Take it out, and put it back. The idea here is to crank the starter within five minutes of taking the battery out of the freezer - when it's nice and cold.

If it won't crank while it's cold, it's on the way out and wants replacing. Don't skimp on buying a new battery...

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