Mercury

Mercury Repair Questions? Ask a Mechanic for Answers ASAP

Ask an Expert,
Get an Answer ASAP!

Mercury

I have a 01 Mercury Mountaineer with the 5.0 that I am on the second alt. Start 1 time and its not charging.

Customer Question
Start the next time and...
I have a 01 Mercury Mountaineer with the 5.0 that I am on the second alt. Start 1 time and its not charging. Start the next time and its charging at 15.2 and the headlights are pulsing.
Submitted: 1 year ago.Category: Mercury
Show More
Show Less
Ask Your Own Mercury Question
Answered in 10 minutes by:
6/27/2016
Mercury Mechanic: Juan Crespo, Tech Trainer replied 1 year ago
Juan Crespo
Juan Crespo, Tech Trainer
Category: Mercury
Satisfied Customers: 1,529
Experience: A.S.E. Master Technician, Advanced Level, Emissions - Asian, Domestic, & European
Verified

Hi there.

That sounds like an internal regulator problem. Before installing the next one, check the wiring; Yellow/White and Black/Orange should have voltage at all times; Light Green/Red should have voltage only when the ignition is on. If those are OK, check engine ground for any possible voltage drops. If all checks out OK, then I would advise getting the next alternator from a different source.

Ask Your Own Mercury Question
Customer reply replied 1 year ago
only 2 wires on plug. yellow/white and green/brown
Customer reply replied 1 year ago
vin is 4m2zu86p31uj05926
Mercury Mechanic: Juan Crespo, Tech Trainer replied 1 year ago

Let me do a little research on that VIN. Be back in a bit...

Ask Your Own Mercury Question
Mercury Mechanic: Juan Crespo, Tech Trainer replied 1 year ago

OK. Yours is a late production vehicle. These have the computer-controlled alternator, whereas the onboard computer serves as regulator.

Basically, the old alternator burnt the driver inside the computer, so now it needs a new computer (PCM) to correct the problem.

Ask Your Own Mercury Question
Customer reply replied 1 year ago
Is that a definite or are we guessing at that fact? Want to make sure before spending the money. And after installation, does it have to be flashed?
Mercury Mechanic: Juan Crespo, Tech Trainer replied 1 year ago

This issue can be easily confirmed with a NGS tester or equivalent scan tool capable of reading that PID.

The PCM would need to be configured to the VIN in order for the security/anti-theft system to work.

Best Regards.

Ask Your Own Mercury Question
Mercury Mechanic: Juan Crespo, Tech Trainer replied 1 year ago

I have to log out for the day. I’ll be back online ready to continue our conversation tomorrow from 2 to 8 PM EST. Please contact customer service at http://ww2.justanswer.com/help if you need immediate assistance.

Ask Your Own Mercury Question
Customer reply replied 1 year ago
Before I put in the ecm, why would this new alt pulse the lights when it is actually charging? When its not charging, the lights are steady and bright.
Mercury Mechanic: Juan Crespo, Tech Trainer replied 1 year ago

An alternator puts out current, not just voltage or amperes. Current is measured in Watts (Watt = Amp X Volt), which is how electrical loads are rated. For example, a starter motor that pulls 60 Amps is actually pulling 720 Watts from the battery (720 Watts = 60 Amps X 12 Volts) As the bad driver in the PCM is erratically exciting the alternator windings, it starts producing erratic amounts of current, which in turn make the electrical loads act erratically as well (lamps will get brighter and dimmer, motors will speed up and slow down, etc.)

In reading your posts, I get the impression that you are not completely convinced of my diagnosis. I understand that, but you also need to understand that Ford designed this computerized charging system to be diagnosed using specialized tools. So, the only way I could tell you what the problem was without any doubts, would be if you had access to a NGS/WDS or equivalent scan tool so I could guide you through all the correct diagnostic procedures. As is, all I can do is offer you my knowledge and experience.

Best Regards.

Ask Your Own Mercury Question
Customer reply replied 1 year ago
why then would the yellow/white wire show 12v and it charges and when it show 5 volts it doesn't?(koeo) That is why I am questioning the pcm replacement. And I am on this site because you are supposed to be the experts. I understand I don't have 20,000.00 for a ford scanner.
Mercury Mechanic: Juan Crespo, Tech Trainer replied 1 year ago

Please allow me to clarify that experts on this site are mostly OEM Master Technicians who have had OEM training and follow diagnosis and repair instructions set forth by the car manufacturers. In other words, being an expert does not mean we know how to diagnose and repair vehicles without using the correct tools.

Back to our Mountaineer, your mention of the Yellow/White wire makes me wonder if we're even talking about the same system. Could you look at the attached diagram and tell me if that fits the vehicle you're working on?

Ask Your Own Mercury Question
Customer reply replied 1 year ago
No. The plug on the alt only has 2 wires. Yellow/white(large) green/brown(small)
Mercury Mechanic: Juan Crespo, Tech Trainer replied 1 year ago

OK. Then it's the one I'm attaching now. In which case, it is not computer controlled - PCM has nothing to do with it.

In this system, the Yellow/White wire is fed from the 30A Alt fuse in the Battery Junction Box and is supposed to have full voltage all the time. If you have fluctuating voltage there, check the fuse and the junction box to see if the connections are clean and tight. If all of that checks OK, then there is a problem with the internal regulator in the alternator.

In some cases, a bad battery will cause similar symptoms. Make sure the battery is load-tested and fully charged before connecting the new alternator.

Please let me know what you find.

Ask Your Own Mercury Question
Customer reply replied 1 year ago
Fuse test good. Battery has been load tested multiple times. All test are above 10.85 volts. So what you are saying now is we have yet another bad alt? Meter isn't fast enough to catch fluctuations, but the lights do when it is actually charging. Does not always charge when truck is started.
Customer reply replied 1 year ago
The yellow wire has one time battery voltage and others around 5 volts
Mercury Mechanic: Juan Crespo, Tech Trainer replied 1 year ago

A battery that's fully charged will have 12.6 volts across the posts after a load test.

As shown on the diagram, the Yellow/White wire comes out of the battery junction box and should have 12 volts.

Do you have access to a Volt and Amp Tester (VAT) that could tell us what the charging rates are with different loads on?

Also, do you know the vehicle's service history that could tell us more on how this happened?

Ask Your Own Mercury Question
Customer reply replied 1 year ago
I could but after initial start, it doesn't charge. Will attempt tomorrow afternoon. Will get with you then.
Mercury Mechanic: Juan Crespo, Tech Trainer replied 1 year ago

Just thought about something; how about running a jumper straight from battery positive to where the Yellow/White wire connects to the alternator? Can you try that and see what happens?

Ask Your Own Mercury Question
Mercury Mechanic: Juan Crespo, Tech Trainer replied 1 year ago

I have to log out for the day. I’ll be back online ready to continue our conversation tomorrow from 2 to 8 PM EST. Please contact customer service at http://ww2.justanswer.com/help if you need immediate assistance.

Ask Your Own Mercury Question
Mercury Mechanic: Juan Crespo, Tech Trainer replied 1 year ago

Hey, man. Just wanted to check and see how you were doing with that Mountaineer.

Best Regards

Ask Your Own Mercury Question
Customer reply replied 1 year ago
Friend from dealership came over and the wire under fuse 30 in fuse panel was frayed causing voltage drop causing alt to not charge. Repaired wire and works fine.
Mercury Mechanic: Juan Crespo, Tech Trainer replied 1 year ago

Thank you for taking the time to give me feedback on this thing - it was certainly one of those I don't hear about everyday.

I hope the jumper I asked you to run helped you and your friend diagnose the issue.

I'm very glad you hung in there and got that puppy fixed!

Best Regards.

Ask Your Own Mercury Question
Ask Juan Crespo Your Own Question
Juan Crespo
Juan Crespo
Juan Crespo, Tech Trainer
Category: Mercury
Satisfied Customers: 1,529
1,529 Satisfied Customers
Experience: A.S.E. Master Technician, Advanced Level, Emissions - Asian, Domestic, & European

Juan Crespo is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

AlvinC answered a question about my Ford truck that only someone with an in-depth knowledge of his subject would have known what was going on.

Rich DUSA

Because of your expertise, you armed me with enough ammunition to win the battle with the dealer. They are installing a fuel filter and fuel pump at no charge to me.

MollyUSA

I needed help with my car on Saturday morning....got a response in 5 minutes, and it was the perfect solution. Thanks again to your service.

Jason V.Kirkland, WA

I do know, after going though this with JustAnswer, that I can somewhat trust my mechanic but I will always contact you prior to going there.

BRNew Jersey

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

< Previous | Next >

Meet the Experts:

Chris (aka- Moose)

Chris (aka- Moose)

Mercury Technician

1,990 satisfied customers

16 years experience with Mercury

John Mc

John Mc

Mercury Technician

403 satisfied customers

19 years Ford Lincoln Mercury experience

Tim&#039;s Auto Repair

Tim's Auto Repair

mechanic

330 satisfied customers

Have owned a repair shop for 25 yrs.

Ron Z.

Ron Z.

- Mercury Tech -

288 satisfied customers

18+yrs experience. State Inspector and Mercury Diagnostics

Chuck

Chuck

ASE Certified Technician

287 satisfied customers

33 Years experience,Ford Senior Master,ASE Master,L1 Advanced Engine Performance

scottz136

scottz136

Mercury Technician

260 satisfied customers

senior master lincoln mercury tech.

Don - Mo Lurch

Don - Mo Lurch

Mecury Mechanic

254 satisfied customers

Ford Cert., Heavy Line Mech, Mobile Electronics. Sales, Installation & Repair for 30 years

< Previous | Next >

Related Mercury Questions
This questions is perhaps for a mechanic or an electrician:
this questions is perhaps for a mechanic or an electrician:I have a 1996 Mercury Sable. Since I barely use it, I want to re-purpose it with an interesting experiment:I want to park it near my house an… read more
fordguy4u
fordguy4u
Automotive Tech
Vocational, Technical or Trade Scho
70 satisfied customers
The anti-theft is stopping my car from starting. I bought a
The anti-theft is stopping my car from starting. I bought a new key a few months ago (I had lost the old one) and it was working just fine, but then I had a different issue with the levels of coolant … read more
David Craig
David Craig
OWNER/MECHANIC
Associates
4,388 satisfied customers
I have a ford escort. When I let car park overnight having
I have a ford escort . When I let car park overnight having hard time starting it. I hear loud pops. In order for the loud pops to occur, I have to push gas pedal to floor and try a while. If I don't … read more
Chris (aka- Moose)
Chris (aka- Moose)
Mercury Technician
Vocational, Technical or Trade School
1,990 satisfied customers
I have a 96 mercury sable and my brake lights will not shut
I have a 96 mercury sable and my brake lights will not shut off … read more
AMEDEE
AMEDEE
AUTOMOTIVE TECHNICIAN
Vocational, Technical or Trade Scho
9,105 satisfied customers
The dash lights go out when it gets dark - digital dash.
the dash lights go out when it gets dark - digital dash … read more
Jaybird61
Jaybird61
Master Automotive Mechanic
2,227 satisfied customers
I have a 2001 Mercury Sable with the Duratech 24 valve
Hi, I have a 2001 Mercury Sable with the Duratech 24 valve engine in it . The car now has 318,000 miles on it. It's never given me any trouble until the last few days. I had trouble with high idle spe… read more
Gary
Gary
Senior Technician
Vocational, Technical or Trade School
58 satisfied customers
Starts run for min than dies. Pth. 2001. Just starting it
Just starting it over and over this is the second time it's done last time it came out of it … read more
Chad Farhat
Chad Farhat
Owner
Associate Degree
4,403 satisfied customers
No spark. 01 Mercury couger. Self. Check coil, crank sensor,
No spark JA: What is the model/year of your Mercury? Customer: 01 Mercury couger JA: Are you fixing your Cougar yourself? What have you tried so far? Customer: Self JA: Anything else you want the mech… read more
Todd M
Todd M
Owner
ASE Certification
1,479 satisfied customers
2003 mercury sable fuel gauge wont read full its eractic and
2003 mercury sable fuel gauge wont read full its eractic and just replaced fuel pump it was doing this before replaced fuel pump as well… read more
HDGENE
HDGENE
Master Technician/Lead Technician
Associate Degree
2,835 satisfied customers
Refilling system with coolant. 250000 or more. Grand marquit
filled the coolant bottle. warmed up the car. no movement on temp gauge … read more
fordguy4u
fordguy4u
Automotive Tech
Vocational, Technical or Trade Scho
70 satisfied customers
2003 Merc Grand Marquis-check engine light comes on-car
2003 Merc Grand Marquis-check engine light comes on-car stutters when i step on the gas-has a hard time going … read more
Chad Farhat
Chad Farhat
Owner
Associate Degree
4,403 satisfied customers
After warming up the low oil pressure light comes on at
after warming up the low oil pressure light comes on at approximately 1000 rpm. If you raise the rpm just above 1000 rpm it goes out. … read more
fordguy4u
fordguy4u
Automotive Tech
Vocational, Technical or Trade Scho
70 satisfied customers
After blowing out a front brake line, I replaced both front
After blowing out a front brake line, I replaced both front lines, rotors and pads, which were due anyway. And yes, I used a vacuum bleeder afterwards. … read more
Chris (aka- Moose)
Chris (aka- Moose)
Mercury Technician
Vocational, Technical or Trade School
1,990 satisfied customers
I just left my car to be towed in the morning,,It cant be
I just left my car to be towed in the morning,,It cant be driven indrive- reverse is bad, but doable. one guy said it was the "tie rod- another said the axel, … read more
Mechanic01
Mechanic01
1,659 satisfied customers
Fuel pump isn't reading. Trying to do it now but when the
Trying to do it now but when the new one is in there is no reading on the gauge … read more
rpmdiag
rpmdiag
High school
7,268 satisfied customers
I have a 2002 Mercury Mountaineer that just started to give
Hello,I have a 2002 Mercury Mountaineer that just started to give me problems yesterday. The truck has driven great since I purchased it almost 2 years ago but just yesterday the engine started to mis… read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
I got a diagnosis that I needed to buy a new engine for my
I got a diagnosis that I needed to buy a new engine for my car—2009 Mercury Mariner at 92, … read more
Chris (aka- Moose)
Chris (aka- Moose)
Mercury Technician
Vocational, Technical or Trade School
1,990 satisfied customers
Air blows out three out of the four vents, one vent barely
Air blows out three out of the four vents, one vent barely has air blowing out of it. When I turn on max, the vent that hardly blows air seems to blow a little more but not nearly as much as the other… read more
David Craig
David Craig
OWNER/MECHANIC
Associates
4,388 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x