Wiring diagram for 2005-09 Mustang GT Fuel Pump Driver Module
Thread Starter
SUPERCHARGED RED ROCKET ------------------Master-Moderator
Joined: May 11, 2006
Posts: 10,644
Likes: 2,509
From: Carnegie, PA
On the FPDM, what’s the relationship between the FP Power, FP Return, and Ground? Looking at the wiring diagram, I noticed the FP power and return are supposed be shielded. Then I see there’s a hashed rectangular box that includes all 3 wires. Does the 1205 GND have to be joined with the return and power wires?
like this. the FP power and return wires are twisted together, wrapped in foil and electrical tape, but are separately insulated. There is a bare wire running along the power/return wires That was very poorly spliced into the Ground wire. I have no clue the purpose of this bare wire.
anyway, with the KOEO, my fuel rail pressure is reading too high (roughly 80 psi). After about 30 minutes, The pressure dropped to around 45 psi. Nearly in optimal range to start. I’ve been getting crack no start symptoms.
I Found This and it Has a Couple Of Ideas Which May or May Not Pertain To Your Car But Here You Go!
Did This Issue Just Pop up Out of The Blue Or Was Something Changed on Car BTW?
Have You Checked For Any Codes BTW as Well!
https://www.s197forum.com/threads/co...e-rail.136108/
KC
Did This Issue Just Pop up Out of The Blue Or Was Something Changed on Car BTW?
Have You Checked For Any Codes BTW as Well!
https://www.s197forum.com/threads/co...e-rail.136108/
KC
Member
Joined: May 8, 2024
Posts: 17
Likes: 2
Here is a Link To Some Other Ford Manual & Wiring Diagram Info For an 08 Mustang. Might Poke Around Here as Well!
A Member Found it awhile Back. I Have Not Used So Not Sure How Good it is in All Area's. He Was Looking For Wiring Diagrams!
Again Just Another Source To Poke Around. Happy To Pull Up Certain Things as Needed!
https://charm.li/Ford/2008/Mustang%2...d%20Diagnosis/
KC
A Member Found it awhile Back. I Have Not Used So Not Sure How Good it is in All Area's. He Was Looking For Wiring Diagrams!
Again Just Another Source To Poke Around. Happy To Pull Up Certain Things as Needed!
https://charm.li/Ford/2008/Mustang%2...d%20Diagnosis/
KC
1. PCM FRP signal (pin 32) - FRPT connector FRP signal (pin1) = 0 ohms resistance
2. PCM FRP signal (pin 32) - FRPT connector VREF signal (pin 2) = O.L
3. PCM FRP signal (pin 32) - FRPT connector FRT wire (pin 3) = O.L
The diagnostics said to REPAIR the short circuit. I have no idea how to repair lol
Also, the Voltage between FRPT sensor connector harness side FRP signal (pin 1) - ground = 5.3v. Which also requires a repair of the short circuit.
Where do I start here?
thanks for all your help
Administrator clevparts@aol.com
Joined: November 27, 2004
Posts: 12,515
Likes: 4,278
From: Visalia Ca.
{If You Have a Break in The Wiring} You Can Do An Overlay. I Know They Would Do This in Some Of The Dealers I Worked At. Usually on a PCM Harness BTW, Time Consuming and Expensive To Replace Whole Harness, So I Would Hear About it Now & Again If The Vehicle had a Wire Break Inline!
It Can Also Be as Simple as a Pin Not Fully Seated in a Connector or a Wire Got Cut Somehow & Grounds Out. The Wires are So Small it Don't Take Much. I Have a Vid I Link To From Time To Time Which Illustrates The Point and Also Has Some Real Good Old School Wiring Detective Work! I Will Supply Link!
https://themustangsource.com/forums/...issues-551265/
Here is The AI Explanation & A Goofy Vid To get The Basics Out There!
Also I Found The FORD Info on it In The PDF!
The Solder Heatshrink Info Should Be Useful as Well as Overlay text on Pg 19!
Anyhoo Hope This Helps.
So I Would Assume You Need To Run a New Overlay Wire From Pin32 to Where it Ends Up.
If The Sensor Pigtail has Issues The Connector Pdf Shows Part Number For Repair Pigtail!
Anyhoo Check Out The Info and See If That Makes Sense for The Issue!
A wiring overlay refers to a repair or modification technique where a new wire or harness is added alongside an existing damaged or faulty wiring harness to restore electrical continuity without replacing the entire original harness. This method is commonly used in automotive and industrial applications when replacing a full wiring harness is impractical, time-consuming, or cost-prohibitive.
The overlay can be used to bypass localized damage such as corrosion, wear, or melting, especially when the damage is less than 20% of the harness or spans less than 6 inches (15 cm). In such cases, adding an overlay wire over the damaged section is recommended. For more extensive damage, such as cracked insulation due to age or heat, or damage from foreign substances like diesel fuel or deicer fluid, replacement of the entire harness may be necessary.
Overlay techniques are also applied in complex systems like engine control modules (ECM), where a new wire is run from the battery to the ECM to ensure stable power delivery, especially in cases of crank-no-start conditions caused by poor grounding or insufficient voltage. Similarly, in throttle pedal wiring, an overlay harness can be spliced alongside the original to restore functionality after damage.
In some cases, a dedicated overlay harness assembly is manufactured for specific vehicles, such as the Land Rover Range Rover Evoque (part number LR176555) or John Deere equipment (e.g., part numbers AA94643 and AA89568), designed for straightforward installation and long-term reliability. These assemblies are built with durable materials and meet industrial standards to reduce the risk of electrical failure.
The process typically involves disconnecting the battery, inspecting the existing harness, using high-quality automotive-grade wire and connectors, ensuring secure crimps, proper insulation with heat shrink tubing, and routing the overlay away from heat sources and moving parts. It is crucial to avoid sharp bends and to secure the overlay properly to prevent interference or damage. For repairs involving connectors, a drag test may be performed to ensure terminals retain proper tension.
In some cases, a more advanced service harness overlay procedure is used, where only critical components (such as those affecting engine start or operation) are disconnected from the original harness, and a new overlay harness is physically laid adjacent to the original while leaving non-critical connections intact. This triage-like method saves time and effort while maintaining system functionality.
It is important to note that overlay techniques should not be used on data communication lines, 5V reference lines, or signal return wires unless specifically designed for such use. Additionally, if the damage extends more than 1 inch (2.5 cm) from the terminal end, a jumper wire may be needed to provide sufficient slack and avoid tension on the connector.
KC
I Edited Some More Info So Recheck Text
9:11 P.m.
It Can Also Be as Simple as a Pin Not Fully Seated in a Connector or a Wire Got Cut Somehow & Grounds Out. The Wires are So Small it Don't Take Much. I Have a Vid I Link To From Time To Time Which Illustrates The Point and Also Has Some Real Good Old School Wiring Detective Work! I Will Supply Link!
https://themustangsource.com/forums/...issues-551265/
Here is The AI Explanation & A Goofy Vid To get The Basics Out There!
Also I Found The FORD Info on it In The PDF!
The Solder Heatshrink Info Should Be Useful as Well as Overlay text on Pg 19!
Anyhoo Hope This Helps.
So I Would Assume You Need To Run a New Overlay Wire From Pin32 to Where it Ends Up.
If The Sensor Pigtail has Issues The Connector Pdf Shows Part Number For Repair Pigtail!
Anyhoo Check Out The Info and See If That Makes Sense for The Issue!
A wiring overlay refers to a repair or modification technique where a new wire or harness is added alongside an existing damaged or faulty wiring harness to restore electrical continuity without replacing the entire original harness. This method is commonly used in automotive and industrial applications when replacing a full wiring harness is impractical, time-consuming, or cost-prohibitive.
The overlay can be used to bypass localized damage such as corrosion, wear, or melting, especially when the damage is less than 20% of the harness or spans less than 6 inches (15 cm). In such cases, adding an overlay wire over the damaged section is recommended. For more extensive damage, such as cracked insulation due to age or heat, or damage from foreign substances like diesel fuel or deicer fluid, replacement of the entire harness may be necessary.
Overlay techniques are also applied in complex systems like engine control modules (ECM), where a new wire is run from the battery to the ECM to ensure stable power delivery, especially in cases of crank-no-start conditions caused by poor grounding or insufficient voltage. Similarly, in throttle pedal wiring, an overlay harness can be spliced alongside the original to restore functionality after damage.
In some cases, a dedicated overlay harness assembly is manufactured for specific vehicles, such as the Land Rover Range Rover Evoque (part number LR176555) or John Deere equipment (e.g., part numbers AA94643 and AA89568), designed for straightforward installation and long-term reliability. These assemblies are built with durable materials and meet industrial standards to reduce the risk of electrical failure.
The process typically involves disconnecting the battery, inspecting the existing harness, using high-quality automotive-grade wire and connectors, ensuring secure crimps, proper insulation with heat shrink tubing, and routing the overlay away from heat sources and moving parts. It is crucial to avoid sharp bends and to secure the overlay properly to prevent interference or damage. For repairs involving connectors, a drag test may be performed to ensure terminals retain proper tension.
In some cases, a more advanced service harness overlay procedure is used, where only critical components (such as those affecting engine start or operation) are disconnected from the original harness, and a new overlay harness is physically laid adjacent to the original while leaving non-critical connections intact. This triage-like method saves time and effort while maintaining system functionality.
It is important to note that overlay techniques should not be used on data communication lines, 5V reference lines, or signal return wires unless specifically designed for such use. Additionally, if the damage extends more than 1 inch (2.5 cm) from the terminal end, a jumper wire may be needed to provide sufficient slack and avoid tension on the connector.
KC
I Edited Some More Info So Recheck Text
9:11 P.m.
Member
Joined: May 8, 2024
Posts: 17
Likes: 2
Here is a Link To Some Other Ford Manual & Wiring Diagram Info For an 08 Mustang. Might Poke Around Here as Well!
A Member Found it awhile Back. I Have Not Used So Not Sure How Good it is in All Area's. He Was Looking For Wiring Diagrams!
Again Just Another Source To Poke Around. Happy To Pull Up Certain Things as Needed!
https://charm.li/Ford/2008/Mustang%2...d%20Diagnosis/
KC
A Member Found it awhile Back. I Have Not Used So Not Sure How Good it is in All Area's. He Was Looking For Wiring Diagrams!
Again Just Another Source To Poke Around. Happy To Pull Up Certain Things as Needed!
https://charm.li/Ford/2008/Mustang%2...d%20Diagnosis/
KC
Given the resistance and voltage readings, can it be deduced that there’s a faulty FRP connector? Maybe corroded pins? I’m considering replacing the connector and splicing into the existing wires.
Administrator clevparts@aol.com
Joined: November 27, 2004
Posts: 12,515
Likes: 4,278
From: Visalia Ca.
You Could Check From Connector Pin in Question To Wire Just After it Comes Out of Plug First Using Your Meter Before Cutting Out Connector. Just Be Real Carefull When Poking Wire To Just Get Through Insulation and Tape Up Well Afterward if Not The Issue. I Would Also Advise Using Electrical Contact Cleaner on Both Connectors and a Recheck as Well First.
It's Hard To Advise Not Being Right There So Trying To Be Cautious in Any Suggestions!
Kc
It's Hard To Advise Not Being Right There So Trying To Be Cautious in Any Suggestions!
Kc
Thread
Thread Starter
Forum
Replies
Last Post