help me

[straits taxi]

my ford windstar will not stay running if i put a new battery and an altenator in it it works for a little while then the rpm guage goes down to zero and it will run but if you turn it off the battery will die iv put new batterys in it new altenaters a new starter but it just wont go what could it be someone tell me please

[Johnny Mullet]

Sounds like you have a draw in the system or a short somewhere zapping your juice and causing instrument interruptions also. First, let's check for a draw in the system..................

Get a test light.
Remove the (+) POS terminal from the battery.
Hook the test light from the disconnected terminal to the disconnected cable.
Does it light up bright? If so, you have a short I can help you find. If not, then we shall try something else.

Has there been any repairs or changes to the vehicle before this started?

[northern piper]

one of the most common parasitic draws are from a blown bulb in the rear door brake light. Check to see if this bulb(s) is blown. I had a drain like you describe that took 3 weeks to find. It was only when I was following my wife home while she was driving the van that I noticed 1 blown bulb.

Piper

[mundy5]

i'm confused as to why a blown bulb would draw. that would mean that a blown bulb in the house would also draw electricity even though it's not running. that seems a bit weird to me since a blown bulb would not complete the circuit...

[northern piper]

yep, it doesn't make any sense at all. All I can tell you is that when a middle stop lamp bulb blows, the dash warning lamp doesn't come on and there is the potential for some sort of short circuit potential. I don't know if there is a series resistor within those bulbs so that if 1 blows they the remaining ones still operate or what. All I can tell you is, after a lot of wiring fiddling, diagnosis, head scratching and swearing replacing the bulb on my van solved the drain problem.

Now whether this is the problem in this case I don't know, but it is an easy check to do.

FWIW my

[Andrew1941]

Could be a short at the bulb through the blown bulb, but not sure why the fuse wouldn't overheat and blow. In my 2001, the light in the dash comes on usually a week or so before a bulb goes. Strange, but it has happened twice where I could not find a bulb out but the light was on. Sure enough after about a week, I would find one blown. When the rear tail gate light blew I was surprised to see that the bulb had been so hot that it melted the plastic holder a bit. Maybe another Ford fubar in the design of the wiring there?

[Johnny Mullet]

Originally Posted by Andrew1941

I was surprised to see that the bulb had been so hot that it melted the plastic holder a bit. Maybe another Ford fubar in the design of the wiring there?

Try removing a 3RD brake light bulb from a Ranger! They melt pretty bad.

[Selectron]

I'm not convinced that we're necessarily looking at a parasitic drain problem - could just as easily be a low charging or no charging problem. A little more detail would be helpful, such as how long it ran for after the new battery was installed. Also, could you let us know if you have a multimeter to make some voltage measurements. If you do, then could you check the following and let us know the results:

=============================================

Voltage after sitting parked overnight, but before starting engine - should be around 12.6V (indicates that there is no excessive current drain with the ignition in the Off position, and that the battery is capable of holding at least some level of charge).

Voltage with engine idling - should be towards the high end of thirteen-point-something volts - maybe just over 14V (indicates that the alternator is producing output current, and that that current is reaching the battery. Also indicates that the rectifier is functioning, converting AC to DC).

Voltage when revving engine slightly - should climb to around 14.2V and then hold steady at that voltage regardless of further increase in engine speed. (Indicates that the voltage regulator is functioning, and clamping the upper voltage threshold at the correct level).

=============================================

Those are fairly general voltages, which will vary slightly from vehicle to vehicle but they're close enough to at least get us started and point us in the general direction of the fault. If the battery is completely flat then of course it will need a recharge before you can do any of that.

[northern piper]

I can't disagree at all. I have no idea if there is a parasitic drain or exactly what's up as the provided info is lacking. But, being lazy and looking at the simple, "tool-less" repairs first, having a blown middle brake light bult is a really easy check. As I said, FWIW, check your bulb. If they're in good shape, the search needs to become more in depth.