No start.. :( Help??

[alwaysready]

ok yesterday driving the xj
(2000 xj limited 4.0 242 automatic..)
when the elec fan would kick on the engine would bog slightly then later the radio was starting to cut out...
later the voltmeter pegged out to 19 volts.....
so i assumed the alt was going bad..
replaced alterantor today drove to work on the way to work the volt meter went to 9 volts along with check light....
i shut it off when i got hear volt metered the battery it says 12.52 volts so its charged but then i cranked it and i got no start..
\so its electrical somewhere...
help??
thakns in advance

 

[alwaysready]

has fuel pressure at rail, checked all fuses they are good...
still searching

 

[97cntryxj]

Mine showed realy high volt readings (pegged out like you said) from coroded battery terminals, I would try cleaning them if you havent already.

 

[aznightkrawler]

I would also verify you battery is still good. You can easily put out 12+ volts on the battery, however if your amps our low you will not be able to start the vehicle. I would have the battery and the cables checked.

 

[alwaysready]

more details..
i had the battery out today while changing the alternator.
i thought it was the alt because what else would peg out the volts gauge except a bad regulator( my thoughts)
i did clean the battery cables and the battery terminals while i had it out..
the volt gauge worked fine for 20 miles then it went to like 9 or no volts whatever was really low..
i checked the battery with handheld V.M. and got 12.5 it turns over fine but wont fire..
so i should have titled this thread its not firing.
the jeep has started fine for the last few months..
and still cranks like normal just no start. im thinking it is a bad connection somewhere causing these issues..
i checked all the fuses with a voltmeter they all checked out ok except 2 had no voltage on either side of the fuse fuses were good though. so i assumed they were just fuses not used on this model..??? of course i should check they were 2 of the small fuses maybe one runs the computer or something... no power to it in the dist block then no start....
Urgg i had to go get my explorer that im tryingh to sell to get home.
lucky i didnt sell it yet

 

[alwaysready]

ive got no tach movement when cranking it over by the key.
whats that mean?

 

[97cntryxj]

possibly crank possiton sensor??

 

[93XJunker]

Just another thought here, check all your chassis ground wires, and if you're brave; I try not to work on anything newer than 95, but try running a jumper wire from a + source to the left side (supply side) of those two fuses and try to crank it, cause aren't the guage clusters and stuff on those newer ones run from the computer? if they are then it sounds like maybe you have a bad ground, or bad connection to the computer. IMHO as long as you run the jumper to the supply side of the fuse, the fuse will still save the circut.

 

[alwaysready]

urghh well i towed it into the shop and he called me the next morning and told me the alt was bad.. its shorting out or something which caused one of the fuses to blow. Urghhh i swore i checked every fuse it was a little fuse under the hood it might have been one of those 2 fuses that had no power on either side.. anyways now to go get my 3rd alternator.
1st, Pep boys, Come to find out was for a Grand cherokee. wouldnt clear the front bracket..
2nd, Fisher, is shorted..
time for the third..