no power

I have a 1994 transprt 3.1, my problem is well many.

1st my problem was that when you put the brakes on the alternator voltage would drop under 13 at times very close to 8. I replaced the alternator, worked fine for a day and again got the same problem. codes read that i need to replace MAP sensor and o2 sensor. i replaced the Map sensor and agian it ran fine for about a day. Then back to when you put the brakes on the voltage would drop to under 13 and rpm would drop, stereo would turn off and then back on, once you too you foot off the brake it would go back over 13(voltage). So i took the alternator out again had it tested, tested good. Had it tested running in the van tested fine, put foot on brake and the nothing happened. Day later back to acting up. Codes that i have got than they disappear; fuel pump low voltage, Map sensor low voltage , O2 sensor low voltage.

I was told to make sure the negitive terminal was ground good. I checked and even added a ground from the motor to the body to make sure. Again everything ran great for a couple days. So during this week when first starting the van (key in on position) it would click for a few seconds when turning over. To a point when you would turn to the on position it would take a sec to have the gages responded. Now when you turn the key to the on position theres nothing. (battery tests fine) When the key are just in the ignition the beep sounds saying you have left your keys in sounds.

Also there no interior lights, power door locks dont work, power mirrors not work, i can live with out these but cant live with out van turning on. Or atleast having power so i can figure out whats wrong.

Thanks for any help
Natascy

Ckecl all your connections from the positive post of battery teminal to ypur starter ensure they are tight and notjing broken. Check same with ground terminal of battery. You have loose wiring somehwere it seems to me.

good luck..

I'd also suspect a bad battery. Weird things can happen with a flakey battery.

I agree with MOBBY. Corroded battery terminals is all too underestimated as caue of low volage and sudden power loss and the source of I guess millions of dollars of unnessessary replacement of batteries/alternators/starters....
while all of this is still possible..but.in last resort.
Corroded side terminals on battery....remove the winshield wash reservoir...can otrageously look normal as dark hard corrosion will let you thnk it is correct..but use a file and clean connectors..cable and battery side...and INSIST...then tighten the connector... THis comes first.
Then look for the rest.
THis ON and OFF problem does look as a bad contact..but yes, a bad battery can do that also..but better try with a temporry no cost replacement if you can borow it form a friend of swap from yur other car....

Battery is brand new, was busy for a couple days so i didnt look at it yesterday went out and started it, again everything running fine lol. But i going to try your suggestions this weekend

Thanks everyone.