87 jeep cherokee won't start

Probably should check to see if there is power going down threw the small wire on the starter solenoid when the key is turned to the start position, that be a good place to start. Double check the battery cables, make sure they are in good shape, clean and tight. If there is no power to the small wire on the starter solenoid, it may be the starter relay, or even an ignition switch.

Find the starter relay in the under hood fuse block. Make sure the vehicle is in park then remove the starter relay and locate cavity #30 and #87 use a short wire to touch these terminals together for a second if the vehicle starts replace the relay.

Change the starter solenoid,the contacts may be burnt

Remove it & open it up to see

I am truly stumped!! Help!!! ???? It's not that difficult if you know how to test electrical circuit's using a wiring diagram an a DVOM - digital volt ohm meter . Free wiring diagrams here http://www.bbbind.com/free_tsb.html
Enter vehicle info. year , make , model . under system click on engine ,then under subsystem click on charging system . Click the search button ,then the blue link . Looking at the diagram on the left , i see the ignition switch ,the crank fuse in the I/P fuse box, the theft deterrent relay an the starter solenoid . Using a voltmeter or test light check for B+ voltage at the S terminal on the solenoid while someone tries to start the vehicle . If no light or B+ voltage ,back track to the relay , Test for B+ voltage at pin's 30 & 87 while cranking . If you pull the relay out of it's socket an look on the bottom or side you will see four set's of numbers 30 & 87 and 85 & 86 . You could just take a piece of wire ,heavy gage 12 . Jump 30 & 87 . If the heavy gage battery cable to the starter is good it should crank the engine .
Starter Voltage Drop
How to Diagnose No Crank No Start Issue Nothing or only Click When the Key...

change the wires that go to the starter i had the same problem fixed now with no problems

start solenoid sounds like the culprit. the start is a breeze to replace. 2-3 bolts and the two power wires. make sure you disconnect the bat. once you have it off the auto parts store should check the starter for free. have them do that befor you buy a new one. also check the fuses if the starter and fuses are good then the ignition is the final link to this puzzle hope this helps

Hi!!
Make sure the battery is fully loaded, check voltage when the key is turned to START. If voltage drops below 10vdc, jump start vehicle and have starting/charging system at AutoZone or similar auto parts store. If voltage at the battery is good, check wiring from battery to starter solenoid, make sure terminals are free of rust and corrosion and tight, wiggle the wires to make sure no loose connections exist. You should get the same voltage at the starter solenoid as you did at the battery terminal, if not replace cable. If you get same voltage at the starter solenoid, the solenoid itself or the starter may be worn/defective. There is a starter rebuild kit available at auto parts stores for a fraction of the price of a new starter.
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Try to check this Jeep Grand Cherokee Laredo. ANTI-THEFT SYSTEM

Hope helps.

Sounds like the starter solenoid is stuck on, most likely need to replace the starter, sometimes what can be done is tap the solenoid with a wrench or a small hammer and it may come loose, if it stops i would still recommend replacing the starter because it will happen again 9/10 times. Also check the wiring to the starter and make sure the start wire is not shorted or installed improperly. If there is constant voltage at the smaller start signal wire, the problem is somewhere in the wiring or the keyswitch.

This means it is the solenoid. But usually on those the starter and solenoid are one unit. They can be purchased individually, but it is usually almost as expensive as replacing the whole unit.