1999 Mercury Mystique Power locks

Tiny
RCROW
  • MEMBER
  • 1999 MERCURY MYSTIQUE
Electrical problem
1999 Mercury Mystique 6 cyl Front Wheel Drive Automatic 130000 kms

Power locks recently stopped working. Doors wont lock or unlock with remote, wont work with in-car buttons, cant even unluck doors with a key. Had to crawl through the trunk the first time. Now I usually leave a door unlocked, but I dont want to. Any suggestions? Sorry, no donation.I have no money, no job, that's why I came here to ask.
Do you
have the same problem?
Yes
No
Saturday, June 5th, 2010 AT 9:45 AM

7 Replies

Tiny
OBXAUTOMEDIC
  • EXPERT
Hello,

Here is some testing to do

These tests are for Vehicle with Anti-Theft System

1. Turn ignition off. Remove and inspect fuse No. 25 (20-amp) from central junction box. Central junction box is located under left side of steering column. If fuse is okay, go to next step. If fuse is blown, replace fuse and retest system operation. If fuse fails again, check for short to ground in suspect circuit. See WIRING DIAGRAMS. Repair as necessary and retest system operation.

2. Disconnect central locking module 13-pin connector C451b (located in right side "A" pillar). Using a voltmeter, check voltage between ground and central locking module 13-pin harness connector C451b terminal No. 1 (Orange/White wire). See Fig. 1. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair Orange/White wire and retest system operation.

3. Press door lock switch to lock position. Check voltage between ground and central locking module 13-pin harness connector C451b terminal No. 10 (Yellow/Violet wire) while pressing door unlock switch. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair Yellow/Violet wire and retest system operation.

4. Press door lock switch to unlock position. Check voltage between ground and central locking module 13-pin harness connector C451b terminal No. 3 (White/Violet wire) while pressing door lock switch. If voltage is more than 10 volts, replace central locking module and retest system operation. If voltage is 10 volts or less, repair White/Violet wire and retest system operation.

These are for Systems Without Anti-Theft System

1. Turn ignition off. Remove and inspect fuse No. 25 (20-amp) from central junction box. Central junction box is located under left side of steering column. If fuse is okay, go to next step. If fuse is blown, replace fuse and retest system operation. If fuse fails again, check for short to ground in suspect circuit. See WIRING DIAGRAMS. Repair as necessary and retest system operation.

2. Remove door lock relay (located in right side "A" pillar). Using a voltmeter, check voltage between ground and door lock relay harness connector C1911 terminal No. 3 (Orange/Blue wire). See Fig. 2. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair Orange/Blue wire and retest system operation.

3. Using an ohmmeter, check resistance between ground and door lock relay harness connector C1911 terminal No. 2 (Black wire). See Fig. 2. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black wire between door lock relay and ground connector located at right "A" pillar. Retest system operation.

4. Press door lock switch to lock position. Check voltage between ground and door lock relay harness connector C1911 terminal No. 1 (Yellow/Red wire) while pressing door unlock switch. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair Yellow/Red wire and retest system operation.

5. Press door lock switch to unlock position. Check voltage between ground and door lock relay harness connector C1911 terminal No. 5 (White/Red wire) while pressing door lock switch. If voltage is more than 10 volts, replace door lock relay and retest system operation. If voltage is 10 volts or less, repair White/Red wire and retest system operation.

.
Was this
answer
helpful?
Yes
No
Monday, June 7th, 2010 AT 3:15 PM
Tiny
RCROW
  • MEMBER
Why cant I just use the key and bypass everything else? I have no clue when it comes to electronics and testing.
Was this
answer
helpful?
Yes
No
Monday, June 7th, 2010 AT 3:52 PM
Tiny
OBXAUTOMEDIC
  • EXPERT
Sorry for delay in getting back with you. Been trying to find out if can bypass system and I cannot find anything. Will post in Mods forum for some input on this.

.
Was this
answer
helpful?
Yes
No
Tuesday, June 8th, 2010 AT 8:50 PM
Tiny
OBXAUTOMEDIC
  • EXPERT
Since your vehicle has a security system it cannot be bypassed. You will need to check Fuses and the power lock control relay its located above the passener side kick panel up top parts.

If you cannot do these checks you will need to have it taken to garage or check for a mobile mechanic to have it repaired.

.
Was this
answer
helpful?
Yes
No
Wednesday, June 9th, 2010 AT 12:58 PM
Tiny
RCROW
  • MEMBER
Thanks for all your help guys, I printed the relay schematic so somebody in the future can check for problems.

Bye
Was this
answer
helpful?
Yes
No
Wednesday, June 9th, 2010 AT 1:06 PM
Tiny
FERNANDO1973
  • MEMBER
Hello Mr.

My name is Fernando and I m mexican. So I hope U can understand what I wanna tell ya.

I ve read what U have written bout power door lock relay for mystique and it has been helpfull for me.

I ve done what U say for car.

"""""These tests are for Vehicle with Anti-Theft System

1. Turn ignition off. Remove and inspect fuse No. 25 (20-amp) from central junction box. Central junction box is located under left side of steering column. If fuse is okay, go to next step. If fuse is blown, replace fuse and retest system operation. If fuse fails again, check for short to ground in suspect circuit. See WIRING DIAGRAMS. Repair as necessary and retest system operation. """"""

Here for this part I replaced the fuse no. 25 and go on.

2. Disconnect central locking module 13-pin connector C451b (located in right side "A" pillar). Using a voltmeter, check voltage between ground and central locking module 13-pin harness connector C451b terminal No. 1 (Orange/White wire). See Fig. 1. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair Orange/White wire and retest system operation.

Here I got the 13-pin connector c451b and it is black.I measured voltage between terminal No. 1 vs ground and I got 11.75 V. Here everything is ok.

3. Press door lock switch to lock position. Check voltage between ground and central locking module 13-pin harness connector C451b terminal No. 10 (Yellow/Violet wire) while pressing door unlock switch. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair Yellow/Violet wire and retest system operation.

Here I measured voltaje between the terminal No. 10 and ground getting 11.65 V while pressing door unlock switch.I suppose it is ok.

4. Press door lock switch to unlock position. Check voltage between ground and central locking module 13-pin harness connector C451b terminal No. 3 (White/Violet wire) while pressing door lock switch. If voltage is more than 10 volts, replace central locking module and retest system operation. If voltage is 10 volts or less, repair White/Violet wire and retest system operation.

Here I Measured voltage between terminal No. 3 and ground getting 0.23 V while pressing door lock switch.

Accordin to what U say the mean problem lies in the white/violet wire but It is kind of hard task to test it.

I suppose I have to follow the wire from C451b connector white/violet cable to. Where? This wire goes from the power door lock relay and goes through the floor down the passenger seat but I don t know where it ends. Do U know where it ends?

Wires seems to be ok and everything is dry on floor.

Could U help me with this trouble please?

Thanks and best regards.
Was this
answer
helpful?
Yes
No
Monday, October 6th, 2014 AT 9:01 PM
Tiny
FERNANDO1973
  • MEMBER
Hello again Mr.

I m Fernando again.

I forgot to tell ya that I checked for continuity between white/violet wire and ground and multimeter says that there is continuity so I think it is not correct.

Thanks and best regards
Was this
answer
helpful?
Yes
No
Monday, October 6th, 2014 AT 9:09 PM

Please login or register to post a reply.

Recommended Guides