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Wiring harness for 1985 F150 EFI 5.0 with MAP sensor

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sgauvry

Wiring harness for 1985 F150 EFI 5.0 with MAP sensor

Gents and Ladies -

I am looking for a complete engine compartment wiring harness for my 85 EFI truck. Purchasing a junk yard harness (if one could even be found) kind of defeats the purpose as I am already dealing with an original harness with many breaks in the lines. The point is that I'd like to purchase a newly created harness that is built to work with my EFI with a MAP sensor.

There are harnesses available for a MAF sensor, but I cannot find any that incorporate the MAP. Any recommendations as to where to find such a harness are welcome.

Steven A. Gauvry - 1985 F150 5.0 EFI

Gary Lewis

Re: Wiring harness for 1985 F150 EFI 5.0 with MAP sensor

Administrator

The others will know for sure, but I'm pretty sure that the ones that use a mass airflow (MAF) sensor also use a manifold absolute pressure (MAP) sensor.

Yours will be an EEC-IV system and according to the new book I have it does use the MAP but not the MAF, which was added with the EEC-V. The years for that varied by the vehicle and its delivery point, but all light trucks (under 8600 lbs GVWR) went to that by 1996.

Bill will be able to answer the question definitively, but I think you can use a harness that has the MAF by removing the extra wires and re-pinning to your ECU connector as the -IV has a smaller connector than the -V.

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

85lebaront2

Re: Wiring harness for 1985 F150 EFI 5.0 with MAP sensor

Administrator

First item, 1985.5 and 1986 5.0L EFI systems are all by themselves, Matt went through that with his 1986. Everything changed in 1987 when EFI became standard on all but the 351 HO and 460 engines. MAF/SEFI started on the 5.0L in 1994 and was still using the EEC-IV system, 1996 was the year for the EEC-V introduction.

That being said, there are a number of sources for an MAF/SEFI for the 5.0L engines, 1985 does not use an electronic transmission so any system for a Mustang update will work, but, you will have some interesting issues. (a) air filter location is unique to those years (b) EEC location is also unique to those years along with the power and fuel pump relays (c) harness routing is unique also, it passes through the firewall in an oval grommet near the throttle cable(d) EGR control system is unique to those years, but some cars used the same system (e) O2 sensor is a 1 wire in the back of the right exhaust manifold, I believe most of the MAF conversions use 2, one in each exhaust pipe, later trucks have it right where the two pipes come together and it is 3 or 4 wires due to the heater. MAF and MAP sensors are completely different circuits, MAP sensor uses the regulated 5 volt sensor and ground circuits and provides a peculiar to Ford high frequency signal that reflects the intake vacuum level (actually measures the Manifold Absolute Pressure in relation to normal air pressure), MAF sensors use the 12V EFI system power and the system ground and then a 2 wire sensor signal connected to the EEC.

Good items, all the sensors are compatible with later computers and the Thermactor solenoids are the same. If you elect to stay with a MAP sensor system, you will need a later sensor. MAF truck air filter units can be found at junkyards along with a mounting bracket. there is a company, fiveology I believe sells a nice kit and does support trucks. Good luck with it!

Bill AKA "LOBO" Profile

"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413

Gary Lewis

Re: Wiring harness for 1985 F150 EFI 5.0 with MAP sensor

Administrator

Bill - Perhaps I misunderstood, but I thought he just wanted a new wiring harness and didn't want to change to a MAF system. If that is true, then is there a harness that would work?

Gary, AKA "Gary fellow": Profile

sgauvry

Re: Wiring harness for 1985 F150 EFI 5.0 with MAP sensor

In reply to this post by 85lebaront2

I appreciate this info and it does give me pause for thought. Not sure I want to convert to an MAF system, as Gary states in a related response.

Steven A. Gauvry - 1985 F150 5.0 EFI

Gary Lewis

Re: Wiring harness for 1985 F150 EFI 5.0 with MAP sensor

Administrator

Maybe you should clarify what the problem is and what your plans are?

Gary, AKA "Gary fellow": Profile

sgauvry

Re: Wiring harness for 1985 F150 EFI 5.0 with MAP sensor

Thanks, Gary. As far as plans go, there's a tremendous amount for me to do. But, the focus now is on replacing the harness.

I found this. It looks identical to my present harness except mine is equipped for the MAP sensor, whereas this one is equipped for a MAF sensor. Painless Performance Fuel Injection Harnesses 60511: https://www.summitracing.com/int/parts/prf-60511

Do you think I could make this work?

Steven A. Gauvry - 1985 F150 5.0 EFI

85lebaront2

Re: Wiring harness for 1985 F150 EFI 5.0 with MAP sensor

Administrator

The problem as I pointed out is the difference in the connections for MAP system and MAF systems. I do not think you will be able to find a new MAP sensor harness anywhere. The later MAP sensor harnesses from the factory are much netter than the 1985.5-1986 ones. I pulled 3 trying to get my son a good one. We finally took the best parts of the 4 (3 I pulled and the original) and made one near perfect harness. To my knowledge the truck, now in Chesapeake VA, still runs fine.

If you are having problems, check where the harness ground connects at the battery negative post, there is a pigtail with a double pin connector, it is maybe 8" long and corrodes to where you either lose the ground or it is so high resistance it doesn't work right. Other common problem, the throttle position sensor, non-Motorcraft ones do not work right,

Bill AKA "LOBO" Profile

PetesPonies

Re: Wiring harness for 1985 F150 EFI 5.0 with MAP sensor

I don't think too much of the aftermarket harnesses, no matter who's it is. I would, in your case, repair my original harness. Some soldering and shrink tube will fix about anything.

Pete's Ponies
Mustang RUSToration & Performance

1982 F100 Flareside
1983 Bronco

sgauvry

Re: Wiring harness for 1985 F150 EFI 5.0 with MAP sensor

In reply to this post by 85lebaront2

"If you are having problems, check where the harness ground connects at the battery negative post, there is a pigtail with a double pin connector, it is maybe 8" long and corrodes to where you either lose the ground or it is so high resistance it doesn't work right. Other common problem, the throttle position sensor, non-Motorcraft ones do not work right,"

I replaced that about two years ago, at the recommendation of Vinny.

Anyway, I want a new harness for the fact that if I indeed refurbish this vehicle, I want it done right before I present it to my boy.

Steven A. Gauvry - 1985 F150 5.0 EFI

sgauvry

Re: Wiring harness for 1985 F150 EFI 5.0 with MAP sensor

In reply to this post by PetesPonies

That's been a thought. But my hands are increasingly more unsteady and my soldering is butt ugly and not very useful. I'd likely do more harm than good.

Steven A. Gauvry - 1985 F150 5.0 EFI

PetesPonies

Re: Wiring harness for 1985 F150 EFI 5.0 with MAP sensor

Soldering is a learned skill. I used to teach it. You can learn to do it. Just a few basic rules to follow and it becomes easy. So why not take an hour and practice? I promise you can learn it and then make your repairs.

Pete's Ponies
Mustang RUSToration & Performance

1982 F100 Flareside
1983 Bronco

NotEnoughTrucks

Re: Wiring harness for 1985 F150 EFI 5.0 with MAP sensor

In reply to this post by sgauvry

On that Painless harness, in a word...No!

If you need an original style harness, I am 99.897% sure that nobody is making one and as Bill pointed out, 85/86 are a breed unto themselves.

Now, If you are interested, I have a good 85/86 harness up here in Saskatchewan. It comes from my Frankentruck, which is getting a retrofit that will enable me to use a later model harness.

I just shipped a harness and other parts to Gary and the cost was not at all unreasonable.

If you are looking for a repair suggestion on your harness, there is an orange wire that connects to a manifold bolt at the back of your LH cylinder head, right by where the EFI harness comes out of the firewall. This is your primary EFI ground for these years and the engine may run with it disconnected, (which commonly happens with engine work), but it's going to be pretty unpredictable.

Gary Lewis

Re: Wiring harness for 1985 F150 EFI 5.0 with MAP sensor

Administrator

Ray/NotEnoughTrucks is the real deal, so if you are interested in his harness don't be worried.

Gary, AKA "Gary fellow": Profile

85lebaront2

Re: Wiring harness for 1985 F150 EFI 5.0 with MAP sensor

Administrator

In reply to this post by NotEnoughTrucks

Further, when I get back over to Newport News, I believe I still have the extra stuff from Matt's 86 and if I do I will bring it back over here and get you some pictures of it and if neither is perfect I will be willing, considering what you want to do to restore one for you, I believe if I remember correctly there are either two or three harnesses that plug into each other.

Bill AKA "LOBO" Profile

sgauvry

Re: Wiring harness for 1985 F150 EFI 5.0 with MAP sensor

In reply to this post by NotEnoughTrucks

What might you charge for your harness including shipping?

Steven A. Gauvry - 1985 F150 5.0 EFI

sgauvry

Re: Wiring harness for 1985 F150 EFI 5.0 with MAP sensor

In reply to this post by PetesPonies

...except my hands shake due to a health issue. Most things that I found easy to do, like use a Phillips head screwdriver, are extremely difficult anymore. Not making excuses. Just the way it is...

Steven A. Gauvry - 1985 F150 5.0 EFI

sgauvry

Re: Wiring harness for 1985 F150 EFI 5.0 with MAP sensor

In reply to this post by Gary Lewis

Thanks for the confidence booster! I'll check with him.

Steven A. Gauvry - 1985 F150 5.0 EFI

sgauvry

Re: Wiring harness for 1985 F150 EFI 5.0 with MAP sensor

In reply to this post by 85lebaront2

Wow! That's quite an offer. I'd want to pay you for your expenses and trouble, of course.

Let me see what transpires with NotEnoughTrucks first.

Never expected to find this sort of willingness to help. Amazing!

Steven A. Gauvry - 1985 F150 5.0 EFI

Gary Lewis

Re: Wiring harness for 1985 F150 EFI 5.0 with MAP sensor

Administrator

I think I should have named this the Bullnose Brotherhood or somesuch. Well done guys!

Gary, AKA "Gary fellow": Profile

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