2001 ford windstar, I posted a question with no responses(gauges crazy, lights on) but I just figured out whats going on with it. I am getting 18 volts at the terminals. battery started to boil. I bought a new battery, and new alternator(voltage regulator built into it) and still have the same problem, 18 volts I assumed the new alt was bad. I had it tested and it was good(14 volts) what can be causing 18 volts?
Country: United StatesMake: FordModel: windstarYear: 2001Engine: 3.8
Hello, I'm Chris.I will do my best to answer your question fast and accurate using the info you have provided. Thanks for visiting Just Answer.
Kind of confused, if you tested at your battery terminals and got 18 volts but tested at the alternator and got 14 volts, how is that possible. Was the alternator not tested while hooked up on the vehicle and running?
I took the alternator off and bought it to the auto store to test I believe the computer controls what the alternator puts out. so can it be a bad wire?
Normally this is not the result of a wire. More often its a faulty PCM or a poor quality alternator on the vehicle that cant be correct tested off the vehicle when its on a vehicle thats computer controlled but off the vehicle manually tested without a computer.
You should start with the test and diagram below to find the fault.
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I checked the procedure out ok Do you know where the center wire of the 3 goes from the voltage regulator? Would the abs pump module be causing this? I know if I unplug the harness from the voltage regulator and run the van, the voltage stays below 14 volts, good.
The ABS should have no effect on this circuit.
VT wire to the PCM
RD/PK wire to the PCM
OG/LB wire to the fuse 13 under the hood
I decided to go to autozone to try a different alternator. It is a bosch cost 200 I put it in and now, instead of 18 volts, I am getting 16 The gauges seem fine I believe 16 is too high, is it? Also, they said about a volt was coming into the battery when the key was off They said I should check to see if I have an open relay. How would I check them? I have an ohm meter, but what would should the readings be?
16 is to high, it needs to be 13-15 volts. There are no relays on this circuit. Many of the Ford tests are going to come up incorrect since a non Ford part is being used. Since you got a volt difference from one aftermarket brand to the next this pretty much tells you its not the vehicle but the quality of the alternators. You should start by putting a motorcraft brand alternator on.
This is driving me crazy. I took off the cables, looked at the relays(before reading your reply) I put it back together, started it, got 14 volts, figured resetting computer must of did it, then all of a sudden, it jumped to 16, then 17.5 volts. I remove the cables again, now its back at 16.5.
Did you complete all the tests I supplied?
Did you install a motorcraft alternator like I mentioned you needed?
If you did both of these and your still overcharging then you have verified the computer is at fault and you need to install a new PCM.
Relist: Inaccurate answer.easy way out is to say its the computer, it can't be, because at times I get 14 volt normal reading. Somethng is causing the higher voltage like an open relay or something
Since you no longer want to work with me and keep wanting to believe Auto Zone (a parts distributor) that there is a relay in this circuit when I (a Ford tech) have provided the Ford wire diagram to prove there is not as well as stated it . I will opt out allowing all other techs to help you from here on out. Good luck and have a great weekend
PS: I doubt there will be many others willing to give up there time like I have, since you have not paid 3 previous experts and this post will make 4 now.
This vehicle is equipped with a powertrain control module (PCM)-controlled "smart charge" charging system. The PCM-controlled charging system is a system whereby the PCM determines the optimal voltage setpoint for the charging system and communicates this information to the voltage regulator. The PCM-controlled charging system is unique in that it has two uni-directional communication lines between the PCM and the generator/regulator. Both of these communication lines are pulse-width modulated. The GEN COM line communicates the desired setpoint from the PCM to the voltage regulator and the GEN MON line communicates the alternator load condition to the PCM. The third pin on the voltage regulator, the A circuit pin, is a dedicated battery voltage sense line.
Now to test this to determine where the problem is hook up your voltmeter to the battery then start engine and run at 1500 rpm for about 15 seconds to initialize the alternator,then disconnect the 3 wire connector on the alternator and take a voltage reading with engine still running. It should read 13.5V plus or minus a couple of tenths. If you are reading 14V or more or 13V or less you have a bad alternator (most aftermarket alternators do not work well with this system,esp Delco).
If the voltage reading is ok then your problem is either wiring or PCM. I would recommend load testing the wires by taking a headlight bulb and disconnecting the PCM and the 3 wire connector then hooking the light bulb between battery positive and the connector wire then grounding the wire at the other end(PCM connector) the bulb should light good and bright as soon as you ground the wire.
I checked the voltage with the 3 wire clip off. It was 13.4 I decided to leve the neg cable off all night, I had done this before with no good reult, this time. I started it up, read 14.3 Perfect I took it for a ride, about 3 miles, everything good, I pulled over, checked voltage, 14.3, fixed? NO I drove 1/4 mile, put my left blinker on, and gauges and lights went crazy, checked voltage, close to 18 again.
Ok your next step is to check the wiring from the 3 wire connector to the PCM. You will need something that will load the circuit down like a headlight bulb or a turn signal bulb and 3 jumper wires.
Disconnect the PCM and the 3 wire connector then take one jumper wire and hook it to the battery positive and then to one side of the bulb,then take another jumper wire and hook it to the other side of the bulb and then to the violet wire,then go to the PCM connector and find pin 20 and hook your 3rd jumper wire to this and then ground the other end of your jumper wire and the bulb should light good and bright. Then do a wiggle test on the violet wire and see if it effects it any. Then repeat this test with the red/pink wire and pin 45 of the PCM.
If both of these wires check good and you have 12V on the orange/light blue wire which is feed by 10amp fuse 13 in the under hood fuse panel then your problem is in the PCM.
33 Years Experience,Ford Senior Master,ASE Master,L1 Advanced Engine Performance
I just got to your reply, I worked on it and just started to wiggle wires around and see if the voltage changes. I got to the square wire harness on top of the transmission that has a bolt holding it together. I wiggled it and the voltage changed. I took it apart and cleaned it with electrical spray, then tightened it up real good. Looks like that was it. I just drove it the same place as before and it seems good, I have to drive it more to know for sure, prob not to tuesday, my battery light is on but probably has to do a cycle to reset, I will let u know soon.
it ended up being the wire that should of had 12 volts, i checked it once, it was good, then again, it was only 9. i eventually traced it to the square wire connector harness, the wire pulled out of it with no effort, i spliced it, solved. Thank you
Glad to here you found the problem! Good Job!