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Engine Wiring Harness Replacements

cloud9

Gary
6,580
7
Sioux Falls, SD
I was contemplating whether I needed to get the upgraded engine wiring harness and sensors from Precision Racing Services this winter. It's something I really would rather not have to spend money to do, but also don't want to have it be a continual issue. I have had two engine wiring harness failures resulting in bad connections to the cam sensors. Each failure occurred after about one year of use (track and street). I would like to get a feel for the failure rate from others before I make a decision on spending that money.

Below is the information I received from Precision Racing Services:

Thank you for your inquiry and yes we do an upgraded version harness for the 302R. This is a package that we developed in conjunction with Ford Racing to address and eliminate the vibration issues and terminal / connector breakage problems with these sensors.

We add military-spec grade wiring pigtails to the following sensors; (4) cam actuators, (4) cam positions, (1) crank position, and epoxy pot them at the sensor wire exit. The wiring is covered in high temp Raychem DR-25 shrink cover and terminated with Deutsch DTM series connectors. We also change out the factory connectors for these sensors on the engine harness for the Deutsch connector. All connectors receive military-spec gold plated terminals. We would need:

- (4) Cam actuators
- (4) Cam position sensors (2 gray / 2 black)
- Crank position sensor
- Engine Harness

On the race versions we also eliminate several connections that are not required. Street car versions retain all the connections.

Individual components are priced as follows:

- Single sensors are $85 each
- Harness modification is $400
- Package price for a full set (9 sensors / 1 harness) is $1000

We do not currently have any premade setups on hand. Our current turnaround time is about 1 week.
 

sadil

TMO Race
401
0
How is the reliability of these things on the continental cars? Maybe some of the team guys on here can chime in. This company must have years of experience from all the years the Boss program was around before the street car was released. Sounds pretty solid.
 

Fat Boss

TMO Addict
1,378
292
What exactly is failing on the harness? Is it a soldered connection breaking, a broken pin, loose connection, or what? Seems like you could modify just about anything to work better if you know exactly what is not maintaining the connection.
 

moto

Ron
248
25
Las Vegas, NV
I have had 2 cam position sensor connectors have pins fail on the harness connector side. Both times they just got the serviceable replacement connector and spliced/soldiered it into the harness vs replacing the harness. I have not had one of the replacements fail again. I have taken a close look at the pins in the connectors(I remember someone suggesting to look closely for silver flakes indicating impending failure) on all four connectors and they look extremely fragile and therefore would be nice to just have a more durable serviceable connector that I could replace all four with?
I haven't had any other harness issues.


Sent from my iPhone using Tapatalk
 

Jimmy Pribble

TMO Addict
665
46
Austin, TX
Aren't you one of those guys that lives in some unreasonable environment that forces you to lock your car away all winter while you play handball in the house like Jack Nicholson in The Shining? Maybe do this instead. About $200.

51EB%2BfLLy3L.jpg
 

cloud9

Gary
6,580
7
Sioux Falls, SD
Jimmy Pribble said:
Aren't you one of those guys that lives in some unreasonable environment that forces you to lock your car away all winter while you play handball in the house like Jack Nicholson in The Shining? Maybe do this instead. About $200.

51EB%2BfLLy3L.jpg
Yes, yes I am.....redrum. Interesting, but the upgraded kit includes replacement sensors as the Deutsche connectors don't work with the factory ones. Thus if you have a failed sensor, you have to get the replacement from PRS, although I've been told there have been no actual reported sensor failures.
 

Jimmy Pribble

TMO Addict
665
46
Austin, TX
cloud9 said:
Yes, yes I am.....redrum. Interesting, but the upgraded kit includes replacement sensors as the Deutsche connectors don't work with the factory ones. Thus if you have a failed sensor, you have to get the replacement from PRS, although I've been told there have been no actual reported sensor failures.
Ah, okay. I didn't understand that detail. I guess I thought new factory sensors were converted.
 

cloud9

Gary
6,580
7
Sioux Falls, SD
Jimmy Pribble said:
Ah, okay. I didn't understand that detail. I guess I thought new factory sensors were converted.
Well they are "converted" since you have to send them all 9 of your factory sensors.
 

Boss_302

TMO Race
351
2
Valrico, FL
cloud9 said:
I was contemplating whether I needed to get the upgraded engine wiring harness and sensors from Pro Race Services this winter.
I googled "Pro Race Services" and found nothing.

I looked the the Boss 302S Owners Manual and found this;

Engine Wiring harness

This harness is a production 5.0L Boss harness that is modified by Precision Race Services (PRS). The four camshaft VCT phasers (cam covers, front of engine), 4 camshaft position sensors (cylinder head, rear of engine) and the crankshaft position sensor (RH rear of engine) connection are modified by Precision Race Services.

Please contact PRS for spares or service parts:
Precision Race Services
16749 Dixie Highway Suite 9
Davisburg, MI 48350
(248) 634-4010 office
(248) 634-4014 fax

Looks like this is the company. http://www.p-r-s.com/main.htm

PRS teams up with Ford Racing .
PRS has been involved with many projects within Ford, building looms for prototypes, testing, and race programs. In 2012 we have applied some of our racing durability lessons to the 302R engine program. PRS has worked with Ford engineers to develop "race hardened" sensor wiring and upgraded sensor connectors. PRS is proud to be involved with another Ford project. Please contact Ford Racing or PRS for more information.


This might be the way to go if there's still problems after warrenty.
 

cloud9

Gary
6,580
7
Sioux Falls, SD
Boss_302 said:
I googled "Pro Race Services" and found nothing.

I looked the the Boss 302S Owners Manual and found this;

Engine Wiring harness

This harness is a production 5.0L Boss harness that is modified by Precision Race Services (PRS). The four camshaft VCT phasers (cam covers, front of engine), 4 camshaft position sensors (cylinder head, rear of engine) and the crankshaft position sensor (RH rear of engine) connection are modified by Precision Race Services.

Please contact PRS for spares or service parts:
Precision Race Services
16749 Dixie Highway Suite 9
Davisburg, MI 48350
(248) 634-4010 office
(248) 634-4014 fax

Looks like this is the company. http://www.p-r-s.com/main.htm

PRS teams up with Ford Racing .
PRS has been involved with many projects within Ford, building looms for prototypes, testing, and race programs. In 2012 we have applied some of our racing durability lessons to the 302R engine program. PRS has worked with Ford engineers to develop "race hardened" sensor wiring and upgraded sensor connectors. PRS is proud to be involved with another Ford project. Please contact Ford Racing or PRS for more information.


This might be the way to go if there's still problems after warrenty.
I mis-typed it as "Pro" versus Precision and yes that's the company I've been corresponding with. The response I posted is directly from them. My issue isn't so much warranty as reliability. I travel anywhere from 5 to 8 hours each way to get to a track. Going home early due to a shorted wiring harness costs me at least $1,000 so that's my dilemma. I posted this to see if I've just been "unlucky" or if it's been a common problem for other street Boss 302 owners. I also have a very early build and thus have a different wiring harness part # than most 2012 Boss 302s. Ford changed the harness part # after 3 weeks of production, likely to address this issue that the race teams uncovered. I tried to get them to use the updated 2012 part # when it was replaced for the second time last May, but they wouldn't do it....only the original part # corresponding to my VIN. I suspect it's because it would require replacing all 9 sensors as well.
 

Boss_302

TMO Race
351
2
Valrico, FL
cloud9 said:
I mis-typed it as "Pro" versus Precision and yes that's the company I've been corresponding with. The response I posted is directly from them. My issue isn't so much warranty as reliability. I travel anywhere from 5 to 8 hours each way to get to a track. Going home early due to a shorted wiring harness costs me at least $1,000 so that's my dilemma. I posted this to see if I've just been "unlucky" or if it's been a common problem for other street Boss 302 owners. I also have a very early build and thus have a different wiring harness part # than most 2012 Boss 302s. Ford changed the harness part # after 3 weeks of production, likely to address this issue that the race teams uncovered. I tried to get them to use the updated 2012 part # when it was replaced for the second time last May, but they wouldn't do it....only the original part # corresponding to my VIN. I suspect it's because it would require replacing all 9 sensors as well.
Didn't mean to make it sound like a dig..........

When exactly was your car built and do you know the date the harness swapped over to the new style?

My car was built 25 Apr 2011.

I also think I recall the 2013 Boss has a different harness as well.

BTW what's a new hanress go for? or would you use the one on your car?
 

cloud9

Gary
6,580
7
Sioux Falls, SD
Boss_302 said:
Didn't mean to make it sound like a dig..........

When exactly was your car built and do you know the date the harness swapped over to the new style?

My car was built 25 Apr 2011.

I also think I recall the 2013 Boss has a different harness as well.

BTW what's a new hanress go for? or would you use the one on your car?
Oh no worries, sorry if it sounded like I took it that way.

Mine was built 28 February 2011 which was the third week of production. Talking to the tech at the dealer, it sounded like the new part # came out for production the following week so you should have the updated part # in your car.

Yes you're correct, they updated it again for 2013.

I'm not sure how much a new harness costs, but my intent is to use the one on my car and that's what PRS recommends. I'm assuming they thoroughly test them after making the upgrades. I think the failure points are the connectors and small wires where they're potted into them, so they're basically removing the parts that have been failing and replacing with new ones.
 

neema

TMO Race
431
109
Fresno, CA
Interested to see how this develops. It seems a little cost prohibitive and time consuming. Bad situation to be in.

My car is back in the dealership for sporadic misfiring and major loss in power (no common causes found). I'll suggest the harness issue and see what they come up with.
 

boro92

TMO Race
367
1
cloud9 - perhaps a silly question, but how did you diagnose that it was a wiring problem to begin with?
What were the symptoms and what caused you to check the sensors?
 

cloud9

Gary
6,580
7
Sioux Falls, SD
neema said:
Interested to see how this develops. It seems a little cost prohibitive and time consuming. Bad situation to be in.

My car is back in the dealership for sporadic misfiring and major loss in power (no common causes found). I'll suggest the harness issue and see what they come up with.
Are you getting any DTCs, CELs or wrench lights?
 

cloud9

Gary
6,580
7
Sioux Falls, SD
boro92 said:
cloud9 - perhaps a silly question, but how did you diagnose that it was a wiring problem to begin with?
What were the symptoms and what caused you to check the sensors?
Not silly at all. The first one began with P0020 Intake Camshaft Position 'A' Actuator Circuit Open (Bank 2) and P0022 A" Camshaft Position - Timing Over-Retarded (Bank 2) DTCs and a CEL. Fortunately there was no significant loss of power, or if there was it was short-lived. I was able to finish the track weekend after clearing the codes. Once I brought it in the dealership called the Hotline and they told them to replace the engine wiring harness. The second occurrence was P0010 (Bank 1) and P0012 (Bank 2) and all the timing was being pulled by the PCM. It was like driving a Honda Civic. I would shut the car off, clear the codes and the CEL would come back within half a lap and all the timing pulled again so an early exit on day 1 of a three day weekend. When I brought it back to the dealer, they Hotline again instructed a harness replacement.
 

cloud9

Gary
6,580
7
Sioux Falls, SD
ArizonaGT said:
Gary I hope this works out for you, what a nightmare.

Neema--have you tried changing the fuel filter?
It's really more about peace of mind. Since it's sitting under a cover for the next few months it's the time to do it if ever. I'm afraid if I don't do it and I have another failure next May on the first day of a 3 day event I'll be kicking myself. It's just curious that I'm not hearing more people run into the issue since it obviously was a big enough issue for the race teams to need to do it. It's all about duty cycle I'm sure, but there are a lot of guys on this board putting significant track miles on their street Bosses.
 

neema

TMO Race
431
109
Fresno, CA
cloud9 said:
Are you getting any DTCs, CELs or wrench lights?
A check engine light showing random misfires as well as specific misfires. Something made the car run rich enough to dump the cats out and decapitate the rear o2 sensors.


ArizonaGT said:
Gary I hope this works out for you, what a nightmare.

Neema--have you tried changing the fuel filter?
Not yet. It seems to be related to the engine running in open loop vs closed loop. The dealership says the o2 sensors are all fine, but it'll snap out of its bogged down misfiring mode and drove at 7/10 power before falling back into its lumpy misfire condition again. It's almost like someone unplugged a few coil packs.


I'll give the fuel filter a try
 

2012YellowBoss

TMO Addict
2,372
10
Sebring, FL
I have done two engine harnesses also and even if the price of the aftermarket is expensive I also lost two days at Daytona because after the CEL the timing was locked. I don't travel as far but it was a waste of over a thousand dollars. You need to ask but to pull the cam sensors I believe you need to pull the engine and timing chain to get at them. Also yes the sensors do go bad, I was told by FR they don't normally go bad but have since been told differently by others. The factory wiring harness is cheap for these cars but takes about two hours to replace if you know what you are doing. The seem to hold up for about a year so the other option is to change it yearly with the plugs, slave, hubs, etc.
 

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