Well, it IS the Motor City.
Condition, Cause, Cure, Cost -- 1992 Mercury Sable elec analysis
The following is a detailed analysis of the electrical failures on this vehicle.
Prior to Oct. 4, the date of this vehicle's check-in, the customer has had a continuous problem with a fuse in the I/P fuseblock blowing. Rather than repairing an obvious circuit overload in the CTSY circuit, (I assume) the vehicle owner instead purchased a large number of high-capacity fuses from a Murray's auto department and proceeded to insert higher and higher rated fuses into the fuse block in an attempt (my guess) to find a fuse that did not blow immediately upon its insertion. The fuse in question protects the circuit from overloads in excess of FIFTEEN amperes. The fuse found in the vehicle upon inspection was rated THIRTY amps, and so was no longer capable of protecting the ciruit from the overload.
Instead, the circuit carried the full thirty amps to the short, which has been determined to be a 1977 U.S. One Cent Piece, (e.g. a PENNY) which had inadvertently fallen into the Ash-tray mounted cigarette lighter in the front center console at some time prior to October 4th and was the root cause of the original fuse-blowing condition. Please bear in mind that the average current capacity of a U.S One Cent piece of any vintage is in excess of 400 Amperes of direct current as determined with similar samples and a DC arc welder.
The remaining fuses from the Murray's service package were found in varying levels of blown-ness in the console of the vehicle. Subsequent applications of these fifteen, twenty, and finally thirty-ampere fuses accomplished the following damage:
*Cigarette lighter jammed with penny welded to inside casing of lighter (would not happen with 15-amp fuse protection)
*Lighted ash tray wiring harness melted due to current in excess of fifteen amperes (would not happen with 15-amp fuse protection)
*Lighted ash tray harness melted together, causing wire-to-wire short
circuit with the interior convenience lighting that is bundled with harness for illuminating the ash tray (you guessed it)
*interior console wiring harnes wire to wire short with ignition harness in dashboard (yup)
*Damage to Vehicle Exterior lighting harness at the junction near the driver's left footwell
*Possible damage (due to backfeed) to the vehicle's Lamp-Out Warning system module
*Possible damage to Climate control head and/or wiring due to proximity of melted harness.
The following end-effect conditions are now evident on the subject vehicle:
*Upon opening any door, the vehicle's rear parking lights, reverse lights, and license plate lights illuminate.
*Upon activating, Parking lights from the headlight main switch, all interior lights (and rear exterior lights as above) illuminate, and the Climate control system and digital dash power up independently of the ignition swith position.
*Upon turning the ignition key to the RUN position, ALL above conditions occur.
The following repairs are required to facilitate safe operation of the vehicle:
* replace Dashboard lower harness $220
* trace and repair wire to wire shorts on Dashboard left harness $137
* Replace Solid state modules permanently damaged by backfeed and/or overvoltage, including Lamp-on warning, Multi-function Turn signal switch, and climate control head $200 +
* Remove U.S. One Cent piece from ash tray and reinstall original 15-amp rated circuit protection device in the vehicle. $35
The estimated cost of this repair (as yet not approved) exceeds five hundred dollars for labor and parts.
I would be happy to credit the customer's one cent, which I have successfully pried out of the ash tray.
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The following is a detailed analysis of the electrical failures on this vehicle.
Prior to Oct. 4, the date of this vehicle's check-in, the customer has had a continuous problem with a fuse in the I/P fuseblock blowing. Rather than repairing an obvious circuit overload in the CTSY circuit, (I assume) the vehicle owner instead purchased a large number of high-capacity fuses from a Murray's auto department and proceeded to insert higher and higher rated fuses into the fuse block in an attempt (my guess) to find a fuse that did not blow immediately upon its insertion. The fuse in question protects the circuit from overloads in excess of FIFTEEN amperes. The fuse found in the vehicle upon inspection was rated THIRTY amps, and so was no longer capable of protecting the ciruit from the overload.
Instead, the circuit carried the full thirty amps to the short, which has been determined to be a 1977 U.S. One Cent Piece, (e.g. a PENNY) which had inadvertently fallen into the Ash-tray mounted cigarette lighter in the front center console at some time prior to October 4th and was the root cause of the original fuse-blowing condition. Please bear in mind that the average current capacity of a U.S One Cent piece of any vintage is in excess of 400 Amperes of direct current as determined with similar samples and a DC arc welder.
The remaining fuses from the Murray's service package were found in varying levels of blown-ness in the console of the vehicle. Subsequent applications of these fifteen, twenty, and finally thirty-ampere fuses accomplished the following damage:
*Cigarette lighter jammed with penny welded to inside casing of lighter (would not happen with 15-amp fuse protection)
*Lighted ash tray wiring harness melted due to current in excess of fifteen amperes (would not happen with 15-amp fuse protection)
*Lighted ash tray harness melted together, causing wire-to-wire short
circuit with the interior convenience lighting that is bundled with harness for illuminating the ash tray (you guessed it)
*interior console wiring harnes wire to wire short with ignition harness in dashboard (yup)
*Damage to Vehicle Exterior lighting harness at the junction near the driver's left footwell
*Possible damage (due to backfeed) to the vehicle's Lamp-Out Warning system module
*Possible damage to Climate control head and/or wiring due to proximity of melted harness.
The following end-effect conditions are now evident on the subject vehicle:
*Upon opening any door, the vehicle's rear parking lights, reverse lights, and license plate lights illuminate.
*Upon activating, Parking lights from the headlight main switch, all interior lights (and rear exterior lights as above) illuminate, and the Climate control system and digital dash power up independently of the ignition swith position.
*Upon turning the ignition key to the RUN position, ALL above conditions occur.
The following repairs are required to facilitate safe operation of the vehicle:
* replace Dashboard lower harness $220
* trace and repair wire to wire shorts on Dashboard left harness $137
* Replace Solid state modules permanently damaged by backfeed and/or overvoltage, including Lamp-on warning, Multi-function Turn signal switch, and climate control head $200 +
* Remove U.S. One Cent piece from ash tray and reinstall original 15-amp rated circuit protection device in the vehicle. $35
The estimated cost of this repair (as yet not approved) exceeds five hundred dollars for labor and parts.
I would be happy to credit the customer's one cent, which I have successfully pried out of the ash tray.
Books by Me | Newsletter | Discussion Group
