Please help me. Ive been trying to work on my sisters 2001 Jeep Grand Cherokee 4.0. She took it to get gas on her way to work and pumped it full of gas. She tried to start it after getting gas but it wouldnt. It would click when you try to turn it over. I went and jumped it off and it would shut off if i didnt give it a little gas. I managed to get the damned thing home to work on it. I checked the battery, starter, and alternator. Everythings good. I noticed a loud clicking coming from the break pedal or fuses, also coming from the fuel pump relay. Ill wiggle the battery harness and it will stop clicking and the dash lights will come on, nothing but a single click when i try to turn it over and everything dies until i wiggle the battery harness again and it gives it some life. Still wont turn over though. Ive been up day and night trying to fix this bastard. I read something on here about the dipstick grounds and it worked for someone but any information or help anyone can give me is greatly appreciated.

 

It sounds like the high current contacts are trying to stay closed but there isn’t enough power to hold them in position so they are opening and closing. I think either there is low voltage or high resistance.

Wiggling the battery cables may be the sign...The contacts of their connections may be loose or heavily corroded. The wires themselves may have too much resistance and need replacing.

Try disconnecting and cleaning the contacts at the starter, battery, main engine and battery grounds, and at the alternator. And then get them put back on again real good and tight after they are all clean.

Check for battery voltage static and while attempting to crank the engine over. It could be a dying battery.

 

Chances are there is a thin film of oxidation on the battery terminals under the cable clamps that's creating a high resistance. Those lead cable ends are notorious for not clamping tight after they get stretched out. Replace the cable clamps or the entire cables and fix the problem.