any ideas why?.....

[teemsta]

the once in a while my 94 jgcl volt gauge runs at 14 my truck runs fine but it drops to around 12/13 after warm up and the truck starts stuttering on the road as if it has like a bad gas filter. that i will replace soon but is there a link between those two things happening to cause the shuttering problem? also its a 5.2 with no check engine light showing. any help would be great. thanx

[JDPascal]

If the voltage is dropping like you say, and the fuel pump voltage is affected, a reduction in fuel supply is possible. A plugged filter might compound the problem. or the low voltage could be affecting the ignition system.

First thing I would do is varify the voltages and battery condition with the right tests

http://assets.fluke.com/appnotes/aut...e/beatbook.pdf

and

http://www.uuhome.de/william.darden/carfaq.htm

or

http://www.trojan-battery.com/Tech-S...e/Testing.aspx

Give some good instructions on battery and electrical tests.

You do need a good digital volt meter. Look at the specifications for the IMPEDANCE. 10,000,000 ohms (10 mega ohms) is the minimum it should have. more is better but you have to pay for it.

and ask more questions if you need to.

JD

[chrisewers]

be careful when using mutimeter with high impedence on battery circuits. because the impedence is so high, it can get good readings even through bad connections. Always test with everything connected so you can see the actual voltage. The voltage drop you see after a while is most likely due to either a faulty regulator in the alternator or faulty signals from the on board computer, which I believe controls the charge, based on load and battery temperature. Check the voltage at the battery it should be over 14v if lightly loaded ie lights andwindow defrost off. Also if you turn off the ignition and measure the battery it should be around 13v and then fall slowly to approx 12v. If the battery is duff you can usually see by looking into each the fill hole (with engine off and wear glasses - splashes are sulphuric acid) if there are any bits floating or signs of water bubbling (cell may be empty) then you have a shorted cell.