On Fri, 21 Jan 2005 10:35:45 -0500, Mike Romain >
wrote:

>Maybe someone here knows the answers to a couple questions a friend of
>mine has regarding Chrysler Fuel pumps and his battery.
>
>He has what he thinks is a dead fuel pump in his 94 Voyager.
>
>So he got a used pump and tested it with 12 volts to see it spin up. He
>then installed it and it still won't spin up in the tank. He 'thinks'
>he heard it spin when he put the key to 'run' once but no start. I am
>disabled and can't get under there to check it for him.
>
>I made a couple observations. One, the 'new' pump has 4 wires off the
>plug and the old one had 3. The ground for the gauge and the motor
>ground appear to be common in the old pump and separate in the new one
>so he soldered the two wires together.
>
>The 'old' pump will also spin up when hooked to a battery.
>
>The fuel pump relay looks good with nice clean contacts inside and on
>the spades and it clicks when the key is turned. Voltage was observed
>at the pump plug. Not enough maybe?

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
>His battery is acting wrong I 'think'. It has a good 24 hours on the
>charger to bring it up over 14 volts.

A fully charged battery is 12.9 volts.

> 30 seconds with the lights on to
>take the surface charge off, then off drops it to 13V. When the key
>hits run, it dives to 12.1 or so volts. When the starter turns, it
>drops to 10.2V.

Anything under 10.4 volts is considered *weak*
but 10.4 volts or better is normal when you put a starter load on the
battery. When you take the load off, it will return immediately to 12
point something.

>I am of the opinion the battery doesn't have enough power to fire it up
>maybe.

See above.

>Could he just plain have the wrong pump in there?
>
>Any suggestions or guesses would be appreciated.

Check the fuel pressure regulator.

Lg


>Mike
>86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>88 Cherokee 235 BFG AT's