Engine Won't Turn Over

>My '90 Cherokee with 4.0/stick refused to start this
>morning. Hit the starter, and it wouldn't turn the thing
>over. I thought it might be the battery, and had someone
>give me a jump, but no dice.
>
>The starter has been turning over slower and slower recently
>so I'm inclined to think it's somewhere in the starter
>and/or solenoid.  Is there any way to test these things, and
>are there possibly other things I should check into.
>
>FWIW, the rest of the electrical system seems fine.  Battery
>measures at 12.67V, and the radio/accessories work fine.

Try the headlights while cranking. If the brown out its
likely a dead battery cell. (This is, of course, a trail
test not a garage method)

- Richard Tucker

1.  Jump the solenoid with a wrench and see if it cranks any
better.  If it does, the solenoid is bad.  Check the battery
connections.  If they are loose or corroded the starter will
not get the juice it needs.  If it doesn't, go to step 2.

2.  Hook jumper cables to the positive side of the battery
and then connect them to the starter.  If it cranks
normally, the cable to the solenoid is bad.  If not, go to
step 3.

3.  Hook the ground side of the jumper cables between the
(-) battery terminal and the bell housing or starter.  Then
touch the (+) side to the starter.  If it cranks normally,
the ground wire to the block is bad.  If it doesn't, see #4.

4.  Make sure the battery is OK UNDER A LOAD.  8 AA
batteries in series will give you 12 volts, but they sure
don't have the 400 amps that the starter needs.  Get a load
tester or swap batteries with another vehicle and see if it
will start that or if the other battery will start the Jeep.
If the new battery still won't turn it over or if the tester
says the battery is OK, it's safe to say it's the starter.
Before you write it off, think back to the last time you
were out mud bogging.  Mud and snot will cause the starter
to fail, but might not require replacement, just a good
cleaning and maybe a rebuild.

I don't know what kind of solenoid the 4.0 has, or more
accurately where it is located.  Chevy starters (solenoid on
the starter) get a bad reputation because the solenoid gets
cooked by the exhaust manifold.  VW (liquid cooled engine)
starters are also notorious.  Ford solenoids (like on the
258) don't have that problem because they're on the fender.
Instead, the starter will engage, kick out, and spin freely
(even more frustrating!).  But they are easy and cheap to
check and fix.  If it's a Chrysler part, you're on your own,
all bets are off, and common sense and deductive reasoning
will not necessarily get you answers. :-)

- Michael L. Courtenay