I had an erratic stalling issue with my 2000 Vulcan, theft light would flash and motor would stall. I could always restart and drive. Theft light flashing threw me off for a long time. Problem got worse with time. Would be worse when engine was hotter. I thought about it a good while. First part I replaced was the relay for the PCM at the front of the engine compartment. This conclusively fixed the problem. 2000 Taurus is now running great again and fun to drive. Little square black part cost $14 from dealer. Dealer said he sold a lot of them. Possibly my best, cheapest, easiest fix ever.
Redtaur2000
In the firewall on the passenger side. Look for a very large loom of wires going into a rectangular connector with a bolt going through the center.
Where is it located on an '03?
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The relay that the OP was referring to is located in the power distribution box near the battery. You can find the diagram in your owners manual of which relay is which.
QUOTE (Redtaur2000 @ Mar 4 2008, 03:59 AM) index.php?act=findpost&pid=600672
Maybe twenty minutes later, I'm cruising at about 70 on the highway and my engine abruptly jumps way up in revs like I switched out of overdrive or was in neutral. Again, the theft light started blinking. I immediately took my foot off the gas and forced overdrive off, letting my car coast back down to the speed limit (55). It drove fine the next half a minute to my exit and I don't remember the stereo cutting off or anything. It didn't do this again the next ten minutes back to my apartment, even though there are more than 10 traffic lights between the offramp and my place. The engine bay didn't seem to have any water in it and the car behaved normally when I drove it later that afternoon with a still-warm engine, as well as late last night with a cold engine.
I remember last winter my battery was close to death, so the car would shudder and go through the motions of turning off when I idled for too long (more than ~20 seconds!), but simply shifting into neutral and keeping the revs up prevented it from happening until I replaced the battery.
So all that text to ask: Is that what you mean by stall? Or is stalling what my car did last winter?
Edit: 11 PM Christmas night. Yeah, it's definitely stalling, and far too frequently now--enough that it's not safe to drive. What causes the relay to fail or short out?
I think I might be having that same issue, after taking my car through a car wash. I noticed that the theft light was doing the slow blink like the car was off with no key in it when I went to shift my car back into drive after the car moving belt released my wheels.
Maybe twenty minutes later, I'm cruising at about 70 on the highway and my engine abruptly jumps way up in revs like I switched out of overdrive or was in neutral. Again, the theft light started blinking. I immediately took my foot off the gas and forced overdrive off, letting my car coast back down to the speed limit (55). It drove fine the next half a minute to my exit and I don't remember the stereo cutting off or anything. It didn't do this again the next ten minutes back to my apartment, even though there are more than 10 traffic lights between the offramp and my place. The engine bay didn't seem to have any water in it and the car behaved normally when I drove it later that afternoon with a still-warm engine, as well as late last night with a cold engine.
I remember last winter my battery was close to death, so the car would shudder and go through the motions of turning off when I idled for too long (more than ~20 seconds!), but simply shifting into neutral and keeping the revs up prevented it from happening until I replaced the battery.
So all that text to ask: Is that what you mean by stall? Or is stalling what my car did last winter?
Edit: 11 PM Christmas night. Yeah, it's definitely stalling, and far too frequently now--enough that it's not safe to drive. What causes the relay to fail or short out?
Car: 2002 Mercury Sable GS, Vulcan engine.
I checked the power distribution box next to the battery.. In the manual box #2 says PCM Relay. But its actually a 30 amp fuse, not the square black relay. And none of the relays in the power distribution box are for the PCM. As far as I understand, what I have to replace is not the fuse. I know it sounds funny like I misread the manual but I am a 100% sure that what it says. I can also attach pics of the power distribution box and the manual. Do you guys have any idea what it might mean?
Edited:
I have found this pic on the internet, but this is exactly how the power distribution box looks like in my car. Which one is the PCM relay?
Fuse panel picture
And this is the Fuse panel diagram from EZ Topic Finder. #2 refers you to the 30 Amp fuse:
Fuse panel diagram
I checked the power distribution box next to the battery.. In the manual box #2 says PCM Relay. But its actually a 30 amp fuse, not the square black relay. And none of the relays in the power distribution box are for the PCM. As far as I understand, what I have to replace is not the fuse. I know it sounds funny like I misread the manual but I am a 100% sure that what it says. I can also attach pics of the power distribution box and the manual. Do you guys have any idea what it might mean?
Edited:
I have found this pic on the internet, but this is exactly how the power distribution box looks like in my car. Which one is the PCM relay?
Fuse panel picture
And this is the Fuse panel diagram from EZ Topic Finder. #2 refers you to the 30 Amp fuse:
Fuse panel diagram
I think you're a little confused with the wording. Fuse #2 is for the PCM power relay i.e. the fuse for the power that goes to the PCM relay. The actual PCM relay is in position #31.
I have the same problem with my 2003 Taurus. I replaced the relay with one from a junk yard and it still had the problem. Bought a new relay and problem is still here. Cleaned off the PCM harness connector, replaced the IAC, problem is still here after the car warms up on the road for about ten minutes! Any other ideas?
i am having a stalling problem with my 99 taurus. could this be the same problem as what is mentioned with these posts. it stalls and the theft light flashes fast and no power anywhere. if i disconnect the neg terminal for a few seconds it starts right back up . problem has gotten worse. any suggestions is t it the pcm relay or the neg battery cable
PATS will not cause the car to stall on it's own. You are either losing charging voltage to the point the PCM shuts down or something is momentarily shutting of the PCM relay. Check and confirm your charging system and battery voltage first.
Erratic Stalling - Flashing Theft light
a
This advice is helpful to me and my mechanic here in St. Louis. My car is at the shop and I'm feeding my mechanic with suggestions like the one above to solve my problem. My problem is compounded by the fact that when I try to start, nothing is happening i.e. I turn key to the right, nothering. I turn the key all the way to the left, nothing. Seems like the security system is not recognizing the key. Anyone have additional things to consider?
a
This advice is helpful to me and my mechanic here in St. Louis. My car is at the shop and I'm feeding my mechanic with suggestions like the one above to solve my problem. My problem is compounded by the fact that when I try to start, nothing is happening i.e. I turn key to the right, nothering. I turn the key all the way to the left, nothing. Seems like the security system is not recognizing the key. Anyone have additional things to consider?
I am dealing with a similar issue on a 2000 Taurus SE.
# 1 - car will shut off while driving and restart in 3-4 seconds by itself then run ok. Sometimes is will completely shut down. I got stranded on the side of the freeway for 20 minutes until it decided to start working again. I noticed the ABS
light on the dash was on very dim, no other dash lights were on while the car was off.
# 2 - When turning the ignition key to the run position, the ABS light will be on very dim, no other dash lights are on , no radio, etc. car will not start. I turn the key off, and nothing happens. If I leave the key in the run position within 10-60 minutes it may decide to just suddenly come back to life electrically. At that point I can either have a successfull start or it will go back to "Electrical Failure mode" as soon as I turn the key to start position.
So far I have done the following with no fix yet:
- Checked with Ford dealer to make sure the formentioned recall for brake light has been complied with. It has.
- replaced the ignition switch
- cleaned and ohms checked the 5 engine bay grounds
- swapped PCM relay out with A/C relay
- split engine bay harness plug and inspected pins and recepticles for damage or corrosion. No defects.
- pulled and checked all relays and fuses in all three electrical panels (2 near the battery in engine bay and 1 under dash)
- with the electrical system in "failure mode" I did a detailed shake and grab of all accessible electrical harnesses under the hood and dash. No effect noted.
- the only thing that can quickly reset the issue is to disconnect the negative battery cable and touch it to the positive cable for 15 seconds. Then reconnecting it the vehicle comes back to life. It may start and run for up to an hour or a couple minutes, or will just go back into "failure mode" as soon as I turn the key to start position.
Battery and charging system checked out ok, I checked for loose connections under the dash, none.
This happens in all weather conditions.
Any ideas what this could be?
# 1 - car will shut off while driving and restart in 3-4 seconds by itself then run ok. Sometimes is will completely shut down. I got stranded on the side of the freeway for 20 minutes until it decided to start working again. I noticed the ABS
light on the dash was on very dim, no other dash lights were on while the car was off.
# 2 - When turning the ignition key to the run position, the ABS light will be on very dim, no other dash lights are on , no radio, etc. car will not start. I turn the key off, and nothing happens. If I leave the key in the run position within 10-60 minutes it may decide to just suddenly come back to life electrically. At that point I can either have a successfull start or it will go back to "Electrical Failure mode" as soon as I turn the key to start position.
So far I have done the following with no fix yet:
- Checked with Ford dealer to make sure the formentioned recall for brake light has been complied with. It has.
- replaced the ignition switch
- cleaned and ohms checked the 5 engine bay grounds
- swapped PCM relay out with A/C relay
- split engine bay harness plug and inspected pins and recepticles for damage or corrosion. No defects.
- pulled and checked all relays and fuses in all three electrical panels (2 near the battery in engine bay and 1 under dash)
- with the electrical system in "failure mode" I did a detailed shake and grab of all accessible electrical harnesses under the hood and dash. No effect noted.
- the only thing that can quickly reset the issue is to disconnect the negative battery cable and touch it to the positive cable for 15 seconds. Then reconnecting it the vehicle comes back to life. It may start and run for up to an hour or a couple minutes, or will just go back into "failure mode" as soon as I turn the key to start position.
Battery and charging system checked out ok, I checked for loose connections under the dash, none.
This happens in all weather conditions.
Any ideas what this could be?
When it is acting up have you tested at the ignition switch for correct voltages?
http://www.taurusclub.com/forum/82-maintenance-repair/179098-no-crank-electrical-issue.html
http://www.taurusclub.com/forum/82-maintenance-repair/179098-no-crank-electrical-issue.html
Just checked voltages at ignition switch. Definitely an issue here. 2.5-3.0 VDC and when I demand current for any additional systems like press the brake pedal for brake lights, turn on headlight switch or turn key to start position this low voltage quickly drops to zero.
While I was taking these readings I heard a subtle click and my voltage increased to 6 VDC. I was still able to bleed it off to zero by turning on headlights and such. Then after a minute or so the electrical in the car came back online and the meter read 11.49 VDC at ignition switch and I wasn't manipulating anything. Then I turned key to start position from run having the 11.49 VDC and everything went to zero again to build back to 2-5-3.0 VDC again. So odd, I am looking for some better wiring diagrams than I have access to on alldatadiy.com to help me trace these wires to the source of there power. Any wiring diagram resources and additional information and guidance is greatly appreciated. Thanks for getting me to look at this issue at the ignition switch, I agree we are on track. I read over the issue you faced and the new wire you had to run. We will see if that is what it comes to for this vehicle.
While I was taking these readings I heard a subtle click and my voltage increased to 6 VDC. I was still able to bleed it off to zero by turning on headlights and such. Then after a minute or so the electrical in the car came back online and the meter read 11.49 VDC at ignition switch and I wasn't manipulating anything. Then I turned key to start position from run having the 11.49 VDC and everything went to zero again to build back to 2-5-3.0 VDC again. So odd, I am looking for some better wiring diagrams than I have access to on alldatadiy.com to help me trace these wires to the source of there power. Any wiring diagram resources and additional information and guidance is greatly appreciated. Thanks for getting me to look at this issue at the ignition switch, I agree we are on track. I read over the issue you faced and the new wire you had to run. We will see if that is what it comes to for this vehicle.
That bundle in the fender has screwed a few of us. Hit me with a PM if you need more direct help with it
So here is what I have found so far with the limited amount of time I have lately to work on this electrical issue.
The ignition switch receives power from a LIGHT GREEN/VIOLET wire. It begins its life from the battery junction box 40 AMP fuse F107. Then goes down the line to a splice that provides power to the starter relay pin 87, the output pin 30 of that relay I presume goes on down to the starter solenoid. From the splice we continue on through the left fender through the firewall to a connector C264 pin 34. Resistance checks between connector C264 pin 34 and fuse F107 are @ 12.4 ohms. A bit too high. I will dig into this more tomorrow.
The ignition switch receives power from a LIGHT GREEN/VIOLET wire. It begins its life from the battery junction box 40 AMP fuse F107. Then goes down the line to a splice that provides power to the starter relay pin 87, the output pin 30 of that relay I presume goes on down to the starter solenoid. From the splice we continue on through the left fender through the firewall to a connector C264 pin 34. Resistance checks between connector C264 pin 34 and fuse F107 are @ 12.4 ohms. A bit too high. I will dig into this more tomorrow.
Rec'd PM. I am at the Red Sox rolling rally and don't currently have access to my diagrams. If you can ask a specific question I will try to provide help. If you need specific diagram assistance try a PM to member Thesavo.
I think I resolved issue
The solution was to replace the battery ground cable. The odd thing is that a regular resistance check with a meter looks great, but once the high amperage demand of the starter trying to crank is attempted only 1 VDC would pass through the cable.
Battery positive post to fender ground was 1.0 VDC
Battery positive post to battery negative post was 12.49 VDC
No obvious sign of corrosion at either end of the cable with just a general look. There was however a small amount of surface corrosion under some heat shrink wrap that was covering the crimp of the battery terminal connector. I can only guess that the issue was within that crimp. Thank you for your help. I hope that this will help others if they stumble upon a similar issue in the future.
The solution was to replace the battery ground cable. The odd thing is that a regular resistance check with a meter looks great, but once the high amperage demand of the starter trying to crank is attempted only 1 VDC would pass through the cable.
Battery positive post to fender ground was 1.0 VDC
Battery positive post to battery negative post was 12.49 VDC
No obvious sign of corrosion at either end of the cable with just a general look. There was however a small amount of surface corrosion under some heat shrink wrap that was covering the crimp of the battery terminal connector. I can only guess that the issue was within that crimp. Thank you for your help. I hope that this will help others if they stumble upon a similar issue in the future.
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