WHY IS MY VOLTAGE FLUCUATING CONSTANTLY FROM 9 VOLTS UP TO 15 VOLTS????

Check the voltage while trying to start it.

You are still getting high or low voltage at tps? What is the voltage and do you have a unstable idle? Put you + lead on terminal 3 and - lead on terminal 1 turn ignition on and check voltage to be at approximately 5 volts. You can also back probe with it connected at center wire and ground probe to a good ground at engine. Turn ignition on it should read between 0.20 - 0.90 slowly manually open throttle it should rise all the way to 4.5 voltd at full open. If its bad change tps if no 5.0 volts from pcm on first test check connections at pcm. The center tps connector supply wire comes from pin 22 and connection 3 ( which is 5 volt supply ) comes from pin 6. You should be able to back probe pin 6 turn ignition on and have 5 volts. If not 5 v brain has problem.

14 volts is close (14.5-14.8 volts is required
and 9 when shut down indicates a bad battery
have it load tested and then have the alternator tested for rectifier pack operation
there should be 14.5 volts DC at the battery when running or it is not charging the battery
if you have 14 volts AC replace the alternator with a serviceable unit

This sounds like a you are having a voltage problem. Have the charging system checked. A bad battery or poor alternator output can cause this. When voltage starts dropping below about 9 volts all kinds of crazy electrical things can happen and they can be anything and anywhere.

Verify that BOTH your positive battery cable AND your negative battery cable have good clean connections at both ends. Make sure that the part where the negative battery cable bolts too on the body of the car is free of rust and a good solid connection. After confirming good connections, then verify that the alternator is charging at between 13.5 and 14 volts when the engine rpm is raised to near 2000 rpm. Check that the battery voltage stays above 10 volts when the starter is cranking and turning the engine over. Once all these things are met, then the system is in good condition. If the battery voltage is too low after a sufficient amount of recharge time, then the battery is probably bad. If the Alternator voltage is too low once you verify a good battery, then the alternator is probably bad.

You need to get a digtal voltage meter (about $15) and check it out yourself-readings at the battery should be 12.5 volts after sitting overnight. Once you start it, the readings at the battery terminals should go up to almost 15 volts when first started, then gradually drop down to around 14.2 volts-I would bet either your battery is bad, or your battery is bad and your alternator has failed trying to supply power to a bad battery-either way, your mechanic should not have allowed the battery light to stay on after changing out the alternator without finding out what was wrong-he did not fix it.

Sounds like system is low on refrigerant and needs to be checked for leaks - could be anywhere on one of these.

A low voltage issue will cause all these symptoms. You should have the alternator checked as well as the battery. Good Luck

lets do this ck voltage with voltmeter at battery post on the back of you alternator. you have to have at least 12.35 volt at least. most likely around 14.-16.. but 12.35 min. any lower replace.

hope2help

TEST B: BATTERY VOLTAGE OUT OF RANGE - DTC B1676
1. Check if vehicle has been jump started within past 2 weeks. If vehicle has been jump started, ABS is
okay. If vehicle has not been jump started, go to next step.
2. Using DVOM, measure voltage between positive and negative battery terminals. If voltage is 9-19 volts,
go to next step. If voltage is not 9-19 volts, diagnose charging system. See appropriate GENERATORS
article in STARTING & CHARGING SYSTEMS.
3. Turn ignition off. Disconnect 25-pin ABS control module. Install EEC-IV 60-pin Breakout Box (014-
00322). Turn ignition on. Measure voltage between breakout box terminal No. 20 and ground. If voltage
is more than 10 volts, go to next step. If voltage is less than 10 volts, repair Light Blue/Pink wire between
ABS control module and instrument panel fuse panel.
4. Turn ignition off. Measure voltage between breakout box terminal No. 25 and ground. If voltage is
greater than 10 volts, go to next step. If voltage is less than 10 volts, repair Red wire between ABS
control module and power distribution box/engine compartment fuse box.
5. Measure voltage between breakout box terminal No. 9 and ground. If voltage is greater than 10 volts, go
to next step. If voltage is less than 10 volts, repair Yellow/Light Green wire between ABS control module
and power distribution box/engine compartment fuse box.
6. Measure resistance between breakout box terminal No. 8 and ground. Also, measure resistance between
breakout box terminal No. 24 and ground. If both resistance measurements are less than 5 ohms, replace
ABS control module and repeat self-test. If either resistance measurement is greater than 5 ohms, repair
suspect Black wire between ABS control module and ground distribution.
NOTE: DTC B1676 will set if vehicle has been jump started.
2000 Ford Ranger
2000-01 BRAKES Anti-Lock - 4WAL - Explorer, Ranger & Mountaineer