Grand Cherokee Won't Start

[Ex4me]

I've got a 95 Grand Cherokee Laredo that won't start. I just replaced the battery about 2 months ago. My daughter left the interior light on over night. Battery wouldn't take a charge so I replaced it with a brand new one. Still won't crank. Inside on the voltage gauge it always read around 14 when you turned on the key switch. Now it only reads between 9 & 14. Jeep will crank & run fine when you jump it of. While it's running it reads 14 volts. After turning it off & trying to re-crank it only reads half way between 9 & 14 on the gauge. I also replaced the negative cable & that's not it either. I'm lost on what to do now besides carry jumper cables every where I go so I can get it started.

[MoJeeN]

If I were you I would take a volt meter to the alternator (the wiring to the gauge in the car can deteriorate. Take a reading from there. May be time for a new alternator.

[dksob81]

the voltage regulator is reading between 9 and 14 volts, when u turn the key to the ON or RUN position? abd it won't crank at all, is that correct.

[Ex4me]

Originally Posted by MoJeeN

If I were you I would take a volt meter to the alternator (the wiring to the gauge in the car can deteriorate. Take a reading from there. May be time for a new alternator.

That is correct. When you switch the key forward without trying to crank & also when you switch it all the way forward to crank it up. It reads between 9 & 14. Kinda like a quarter tank of gas. When you jump it off it reads 14. Also while sitting there running it reads 14 volts. After cutting it off & trying to crank it back, it reads between 9 & 14 again.

[dksob81]

well u can test the altenator by starting the jeep and disconneting the negative battery cable while the jeep is running, if it dies then the alt is bad if it continues running then it is good,

leave the cable off for a minute or so, if it dies at all then it's time for a new altenator.

[dksob81]

also the engine doesn't crank at all when u try to start it, without being jumped?

[MoJeeN]

Originally Posted by dksob81

also the engine doesn't crank at all when u try to start it, without being jumped?

Well, work your way backwards from the battery. Alternator, then solenoid, ignition etc.

[Ex4me]

Originally Posted by dksob81

well u can test the altenator by starting the jeep and disconneting the negative battery cable while the jeep is running, if it dies then the alt is bad if it continues running then it is good,

leave the cable off for a minute or so, if it dies at all then it's time for a new altenator.

It doesn't do anything. No clicking, slow turnover or anything. Also after jumping it off & getting it cranked, you can turn everything on & the voltage doesn't even drop. Like the lights, radio etc........ Going outside now to check the alternator.

[Ex4me]

Originally Posted by Ex4me

That is correct. When you switch the key forward without trying to crank & also when you switch it all the way forward to crank it up. It reads between 9 & 14. Kinda like a quarter tank of gas. When you jump it off it reads 14. Also while sitting there running it reads 14 volts. After cutting it off & trying to crank it back, it reads between 9 & 14 again.

I jumped it off to get it running again. After getting started I disconnected the negative cable from battery & left off for a few minutes. Jeep kept running & never cut off. Went to the inside & cut off the key & won't crank back. Guess the alternator is good. Now which direction do I head? Thanks for all the help so far guys.

[dksob81]

well the altenator is prolly not the problem, have u used a Voltmeter and tested the battery when it is off, it should read around 12.6 volts.

[Ex4me]

Originally Posted by Ex4me

I jumped it off to get it running again. After getting started I disconnected the negative cable from battery & left off for a few minutes. Jeep kept running & never cut off. Went to the inside & cut off the key & won't crank back. Guess the alternator is good. Now which direction do I head? Thanks for all the help so far guys.

Haven't used a volt meter but the battery is good. I took the battery out of the Jeep & put in my F150. Truck cranked fine. Also took the battery from my truck which is only 1 year old & placed in the Jeep. It still wouldn't crank & I still got the same voltage reading as before. Between 9 & 14 with the truck battery. That's how I determined it wasn't the battery.

[dksob81]

hummm thats wierd. have u checked the connection to the PCM.

[Ex4me]

I'll check it in the morning. Already dark outside here. Thanks for the help & if anyone else has an idea please post.

[Dale Aeppli]

Originally Posted by Ex4me

Haven't used a volt meter but the battery is good. I took the battery out of the Jeep & put in my F150. Truck cranked fine. Also took the battery from my truck which is only 1 year old & placed in the Jeep. It still wouldn't crank & I still got the same voltage reading as before. Between 9 & 14 with the truck battery. That's how I determined it wasn't the battery.

when you jump start it, are you hooking the positive post to the positive post and the negative to negative post or are you hooking the negative from jump vehicle to the engine block on your jeep. if you're hooking negative post from other vehicle to your engine block you have a bad ground in your jeep. [email protected] Dale

[Ex4me]

I'm hooking from post to post on both batteries. Not using the frame as a ground.