Sometimes it starts and sometimes nothing happens

If it is an auto transmission, it could be the Park and Neutral Position switch. When problem occurs, try shifting to N and see if you can start.

The other thing would be the ignition switch. The starter circuit is not contacting. At the starter relay, test for battery voltage at the ignition switch terminal with key cranked to start. If battery voltage is availabe, then problem is at relay or starter.

Try giving the starter a few knocks to see if it kick in.

CHECK THIS TOO

OTHER THAN WHAT WAS ALREADY SUGGESTED--THINGS YOU "MAY HAVE" LOOKED AT ONCE. MAYBE YOU NEED TO DIG A LITTLE DEEPER

SOMETIMES IT'S JUST A MATTER OF GETTING IN THERE, AND GIVING IT SOME "TOUGH LOVE"

TRY THIS STUFF, BE "DETERMINED" WITH THE CONNECTIONS!

THIS IS SORTA GENERIC

YOU COULD HAVE OTHER PROBLEMS

INSURE YOUR BATTERY IS GOOD. AND ONCE YOU GET IT RUNNING, YOUR ALTERNATOR IS CHARGING (CAN BE CHECKED FOR FREE AT MOST AUTO PARTS STORES)

USUALLY THE PROBLEM IS SOMETHING EZ TO FIX

YOU COULD ALSO HAVE FAULTY RELAYS OR FUSES OR EVEN A BAD NEUTRAL SAFETY SWITCH. BUT LET'S SAVE THE COMPLICATED CRAP FOR LAST! (IF ANY)

CHECK YOUR FUSES!---YOUR OWNERS MANUAL MAY SHOW YOU LOCATIONS THAT YOU KNEW NOTHING ABOUT!

REMOVE AND REPLACE "SUSPECT" FUSES SEVERAL TIMES--THIS MAY SCRAPE OFF CORROSION AND GIVE THEM BETTER CONTACT IN THE FUSE BLOCK!

THIS "FIXIN A BAD CONNECTION ISSUE" WILL WORK FOR YOU, PROVIDED THAT YOUR BATTERY IS GOOD---OR YOU CAN BE JUMPED OFF! (AND IT AIN'T A MORE SERIOUS ISSUE). EVEN IF YOU HAVE TO BORROW YOUR NEIGHBOR "FRED'S" GOOD BATTERY OUTTA HIS TRUCK, FOR A TRIAL RUN. YOU ARE TRYIN', NOT JUST SITTING AROUND SPECULATING!

REMEMBER "NEW STUFF" CAN BE BAD TOO!

YOUR STARTER MAY BE BAD!

YOUR SOLENOID MAY BE BAD!

BATTERY COULD BE BAD!

MOST OF THE TIME, WHAT YOU ARE ABOUT TO READ BELOW IS USUALLY THE PROBLEM, YOU CAN "GET MOTIVATED" AND FIX IT, OR PAY SOMEONE THE BIG BUCKS TO FIND IT!

MOST SHOPS HAVE NO MERCY, NOT TO MENTION A TOW BILL.

PEOPLE GET LAZY!----THEY DO NOT ACTUALLY DO THIS STUFF. JUST A QUICK GANDER FROM AFAR AND HOURS OF "IT COULD BE."---AND NO HANDS ON

IT BITES 'EM IN THE BUTT. THEY COULDA BEEN RIDING LONG AGO!

****DISCONNECT THE BATTERY TO DO ALL OF THIS*******

********TAKE STUFF LOOSE, LIKE BATTERY/ STARTER/ SOLENOID/ ETC CABLES ETC (REALLY!--EVERY ONE OF 'EM! ONE AT A TIME)*********

CLEAN"SCOOCH" THE CONNECTORS AROUND----TIGHTEN THE NUTS OR BOLTS WELL, WIRE BRUSH, KNIFE BLADE, WHATEVER IT TAKES TO CLEAN A CONNECTION! DO NOT JUST PASS OFF ANY BIG CABLE CONNECTION AS, "IT LOOKS GOOD".I MEAN MAN HANDLE EVERY CONNECTION EVERYWHERE!

PAY SPECIAL ATTENTION TO THE BATTERY POSTS---CLAMPS---CABLE CONNECTIONS TO THE CLAMP (I'M TALKING ABOUT THE OLD STYLE "SQUEEZER" DEALEES, THAT HOLD THE CLAMP TO THE ACTUAL CABLE)

IF YOU HAVE SIDE POST TERMINALS---REMOVE THE BOLT THAT SCREWS INTO THE BATTERY FROM THE SIDE TERMINAL (IT WILL POP OUT OF THE RUBBER)--TURN THE RUBBER INSIDE OUT SCRUB THE FLAT CONNECTOR WITH A WIRE BRUSH OR SCRAPE IT WITH A KNIFE, TILL IT'S CLEAN---SAME FOR ITS MATING SURFACE ON THE BATTERY!

MANY TIMES THERE AIN'T MUCH SLACK IN THE CABLE----NO WHINING!---YOU GOTTA GET IT CLEAN, ESPECIALLY IF YOU CAN SEE "GREEN CRAP" CAKED ON 'EM!

YEAH, IT'S NOT EZ TO GET IN THERE, BUT LOOK AT WHAT YOU WILL HAVE TO PAY IF YOU DON'T!

THIS IS WAR--YOU GOTTA CHECK IT ALL--ANY CONNECTION---POSITIVE OR NEGATIVE THAT A BIG CABLE BOLTS TO. GET YOUR HANDS DIRTY!

IF A CABLE GOES TO A BOX--IT GOES ON THRU IT---CLEAN CONNECTIONS COMING AND GOING---TO WHERE EVER THEY GO!

EVENTUALLY YOU WILL REACH THE STARTER CONNECTION (POS)AND THE ENGINE/ BODY (NEG)

DON'T TELL THE SHOP, AS YOU GIVE 'EM YOUR $$$---WHILE WHINING---"CJ MEDEVAC TOLD TO CLEAN THAT CONNECTION, AND I DIDN'T!"

AS YOU PROGRESS, TRY TO CRANK HIM UP---YOU MAY FIND EXACTLY WHICH CONNECTION WAS THE PROBLEM!

I'VE SEEN THIS SAME CATASTROPHE, MANY MANY TIMES (I SAW IT NOT TOO LONG AGO), AS I WAS ABOUT TO "CAR DOLLY" A FRIEND'S TRUCK IN, THEN I DID THE CHECKS, IT WAS THE SIDE POSTS ON THE BATTERY CONNECTIONS). AND IT'S SO SIMPLE TO FIX. SAD THING, WHEN I GOT THERE, NOTHING HAD BEEN DONE 'CEPT AN ATTEMPTED JUMP START.I WAS GONNA HAVE TO PULL HIM 40 MILES, HE WASTED 3 HOURS OF MY TIME. LAZY, LAZY, LAZY

YOU COULD BE RUNNING BEFORE YOUR "CALVARY" ARRIVES!

THE PIC I SHOW IS ANOTHER JEEP FRIEND OF MINE'S BATTERY CONNECTION---HE TOO STOOD BACK AND INFORMED ME HE HAD CHECKED THIS CONNECTION. HE GOT MAD WHEN I "RECHECKED IT" ANYWAY, 'CEPT I TOOK OUT MY KNIFE AND SKINNED BACK ELECTRICAL TAPE AND SOME INSULATION. THE "MAJOR PROBLEM" WAS CORROSION FORMED A "BARRIER" BETWEEN THE WIRE AND THE CLAMP WHERE THEY WERE CRIMPED TOGETHER.

RETURN WITH GOOD NEWS!

OR YOUR FINDINGS AND WE WILL CONTINUE

THE MEDIC

JUST BECAUSE THE RELAY "ACTIVATES" DOES NOT MEAN JUICE IS ACTUALLY BEING TRANSFERRED THRU IT

CAN YOU FIND IT'S EXACT TWIN FOR ANOTHER SYSTEM AND SWAP THEM AS A TEST?

THE MEDIC

The ignition switch up to the relay is good. What you need to test now would be the starter itself and power supply to it.

With ignition switch turned to crank, use the multimeter to test the starter solenoid wire for battery voltage, if voltage is available, the starter is bad. Try applying battery voltage to the solenoid to see if it click and cranks.