I desperately need a wiring diagram for a mass air flow wiring loom. Please help me

The relevant Haynes manual should have the wiring diagram in it.

http://goo.gl/0MbLRw

You may also find it useful if you are going to be randomly poking around in your engine.

(edited 8 years ago)

Reply 3

CurlyBen

19

For the love of god, just take it to somebody competent. 30 seconds on google had me looking at a wiring diagram which, if not the exact circuit on your car, is at least close enough to be a starting point. The problem is that judging by your description neither you nor 'Brian' actually know what's been done and don't know enough to reverse the damage that's already been caused. For a start we don't know whether this 'loom' that's been cut is the engine wiring loom (the MAF won't have its own dedicated loom) or simply the wiring from the MAF to the plug.

Saying the wiring colours 'look wrong' is a sign of someone well out of their depth. Anyone competent wouldn't be relying on wiring colours for anything more than tracing wires.

Normally I'd just ignore you from now on, but some of the bodges you've described 'Brian' performing on your car aren't just piss poor workmanship, they're actually downright dangerous.

If you really insist that you won't take your car to someone that knows a multimeter from a soldering iron, at least post up a picture of what's been cut so we've got half a chance of identifying it.

Reply 4

OP

Original post by Nuffles

Go to scrap yard. Open bonnet of same car with same engine. Unplug MAF loom and follow it back a couple of feet. Cut off loom. Cut out all the rat's nest you have in your car and solder/heatshrink or crimp in the new loom you have. Boom - done. Did this exact repair on my old car, but with part of the injector pump loom.

Hi Nuffles, thank you so much for trying to help me.

I really, really hope and would truly greatly appreciate if you can assist me to try and resolve this issue.
I am very upset and frustrated and it is really stressing me out
I have had this problem with the maf on my car for around 6 months now since My mechanic friend , Brian, cut the ends off my maf wiring loom because they were torn causing check engine light on. when he inspected the loom he said it looked wrong, cant remember why.

He tried looking on the internet and said he could not find the wiring loom diagram anywhere and says he is stumped, even the Ford dealership weren't of any help.
He has guessed several times and using connectors he tried swapping color wire sequences but still the problem persists.
He then took off the original 6 pin maf sensor and put on a 4 pin maf sensor, he connected 4 wires from the loom to it and put 2 in a loop, he later cut off the 2 wires that he put in the loop and said they were just an open loop and not needed, but now several people are saying he was stupid to cut the 2 wires off and that they were needed.
people say the 2 wires he cut off can be replaced, spliced back in, but when looking at the maf wiring I can not see anywhere that you could splice them in, you can't even see where they have been cut and where they would even fit in.
since altering it my car does not stall anymore but does not go past 70 mph atm as once it hits 70 or is revved to hard it thuds quietly then refuses to accelerate, this is due to cut wiring as only first happened the day wires were cut.

My friend is now suggesting we put the original 6 pin maf sensor back on but we need to get a new plug end to wire the 6 pin sensor back on.
I have never saw a car the same as mine in our local scrapyard, besides, my mechanic friend, Brian ,upon inspecting the wiring loom on my car said that the wiring looks wrong, can't remember what exactly he said but he said it looked wrong.

I had my car booked in with an auto electrician but Brian told me he knew how to fix it so I cancelled and it turned out Brian didn't have a clue how to fix it. I would like to give him 1 chance more to try fix it for me or I will probably just go to auto electrician. I at least want original sensor back on first and would like to find wiring diagram first too.

I have spent loads of money on this car and have only had it around 8 months, I spent thousands of pounds on previous cars too so need to keep cost low on this job but need a good job doing.

please please help.

Thank you

Reply 5

Original post by I love life

since altering it my car does not stall anymore but does not go past 70 mph atm as once it hits 70 or is revved to hard it thuds quietly then refuses to accelerate,

Not a huge problem, given the speed limit.

Brian ,upon inspecting the wiring loom on my car said that the wiring looks wrong, can't remember what exactly he said but he said it looked wrong.

To know this he would need to be familiar with the wiring of this particular engine or have the wiring diagram. We know he doesn't have the latter!

please please help.

Thank you

I have told you where to find the diagram.

Out of interest, does "Brian" have any qualifications or work at a garage?

Reply 6

OP

Original post by CurlyBen

For the love of god, just take it to somebody competent. 30 seconds on google had me looking at a wiring diagram which, if not the exact circuit on your car, is at least close enough to be a starting point. The problem is that judging by your description neither you nor 'Brian' actually know what's been done and don't know enough to reverse the damage that's already been caused. For a start we don't know whether this 'loom' that's been cut is the engine wiring loom (the MAF won't have its own dedicated loom) or simply the wiring from the MAF to the plug.

Saying the wiring colours 'look wrong' is a sign of someone well out of their depth. Anyone competent wouldn't be relying on wiring colours for anything more than tracing wires.

Normally I'd just ignore you from now on, but some of the bodges you've described 'Brian' performing on your car aren't just piss poor workmanship, they're actually downright dangerous.

If you really insist that you won't take your car to someone that knows a multimeter from a soldering iron, at least post up a picture of what's been cut so we've got half a chance of identifying it.

Hi , thank you for helping.

I want to get the original 6 pin sensor back on and find out the wiring diagram and then I think I will go back to an auto electrician after cancelling last time because Brian told me too but turns out he lied to me saying he had worked out how to fix it.

Can you please share with me what wiring diagram you found ?! I would like to take a look and maybe print it off at the library and show it to Brian.

Brian says by looking at maf wiring that it looked wrong, can't remember why . Maybe he found a diagram similar to the one you found and the colors were completely different maybe ?

But I would like to see a pic of the diagram you found.

The loom that has been cut I am pretty sure is just the wiring from the MAF to the plug, it is only 2-5 inches from sensor.

oh, and what did you mean by

Saying the wiring colours 'look wrong' is a sign of someone well out of their depth. Anyone competent wouldn't be relying on wiring colours for anything more than tracing wires.

please?

the colors of the wiring do matter.

What did you mean by Brian performing dangerous work on my car ?

And sure, I will try and post some pics of the wiring and hopefully you'll be able to see it okay and have a better idea of what is going on.

thanks

Reply 7

Original post by I love life

Saying the wiring colours 'look wrong' is a sign of someone well out of their depth. Anyone competent wouldn't be relying on wiring colours for anything more than tracing wires.

please?

the colors of the wiring do matter.

Technically, the colour of the wires are unimportant as long as they are connected to the right place. Unless he had a wiring diagram and checked both the ECU end and the MAF end, he wouldn't have known it was wrong.

Also, the number of wires and their colours WILL be different on different engines on the same vehicle.

(edited 8 years ago)

Reply 8

OP

Original post by Talon

1. Not a huge problem, given the speed limit.

2. To know this he would need to be familiar with the wiring of this particular engine or have the wiring diagram. We know he doesn't have the latter!

3. I have told you where to find the diagram.

4. Out of interest, does "Brian" have any qualifications or work at a garage?

1. Why should I have to put up with a top speed of 70 mph ?? Sometimes when over taking on a motorway you need to pick up a bit more than 70 mph.
Also it happens at 70 mph because the revs are high but it can happen at any speed wherever it is being revved hard, if going up a hill and I put m,y foot down it will thud and refuse to pick up speed or accelerate, if I'm accelerating on a carriageway or any road where I need to pick up speed it will do it then sometimes too. it shouldn't be doing it hence why I want it sorted.

2. Agreed, but maybe he found a wiring diagram online but they were completely different colors that are on my wiring loom so he may think it is the wrong diagram he is looking at or he thinks I already have the wrong wiring on my car.

3. Yup. you said a Haynes manual for my car, but I went to a car parts shop to buy something else and once there I asked him if a manual would reveal the wiring diagram and he said he very much doubts it.

4. Yes, Brian is a Master Technician and worked at a taxi repair garage when he lived in the Isle of Man. now he has his own business working from home repairing cars, he is out almost 24/7, even working on car's early hours in the morning as he has sleep problems too he does not mind working all through the night as well as day.

Reply 9

OP

Original post by Talon

Technically, the colour of the wires are unimportant as long as they are connected to the right place. Unless he had a wiring diagram and checked the ECU end and the MAF end, he wouldn't have known it was wrong.

Also, the number of wires and their colours WILL be different on different engines on the same vehicle.

But the color of the wires are sort of their to make sure the person knows the wires should be in the right place? the colors do indeed matter.

so if this is the case, how would checking a car manual help me if wires are different on every single car of the same type ?

Reply 10

Original post by I love life

But the color of the wires are sort of their to make sure the person knows the wires should be in the right place? the colors do indeed matter.

Yes, but that will only help if you have the wiring diagram as that will tell you what colour goes where. It isn't as simple as "blue = data, red = +ve" etc.

so if this is the case, how would checking a car manual help me if wires are different on every single car of the same type ?

I didn't say every car was different, I said that if a car has a different engine, the wiring will be different. The Ford Focus from 05 to 09 apparently has 3 different possible diesel engines. The wiring in one is not necessarily the same in the other two.

Original post by I love life

3. Yup. you said a Haynes manual for my car, but I went to a car parts shop to buy something else and once there I asked him if a manual would reveal the wiring diagram and he said he very much doubts it.

Obviously I haven't read the manual for your car, but I have the Haynes manual for my Freelander and it has wiring diagrams for everything in the back, including the engine management systems which is what you want.

(edited 8 years ago)

Reply 11

OP

Original post by Talon

1. Yes, but that will only help if you have the wiring diagram as that will tell you what colour goes where. It isn't as simple as "blue = data, red = +ve" etc.

2. I didn't say every car was different, I said that if a car has a different engine, the wiring will be different. The Ford Focus from 05 to 09 apparently has 3 different possible diesel engines. The wiring in one is not necessarily the same in the other two.

3. Obviously I haven't read the manual for your car, but I have the Haynes manual for my Freelander and it has wiring diagrams for everything in the back, including the engine management systems which is what you want.

1.

1. Well, you said technically the color of the wires were not important as long as they are connected to the right place.
well how would you know or not if they were in the right place if not for the colors of the wires ???

1. Well, you said technically the color of the wires were not important as long as they are connected to the right place.
well how would you know or not if they were in the right place if not for the colors of the wires ???

2. Oh, okay. I see the misunderstanding there.

3. ok, maybe the guy in the auto parts shop was wrong, do you think I could pick up a manual anywhere and check first before buying it ?
and how would I know it is for my engine when you said there is probably 3 versions to these engines ?

Reply 12

CurlyBen

19

Original post by I love life

Hi , thank you for helping.

I want to get the original 6 pin sensor back on and find out the wiring diagram and then I think I will go back to an auto electrician after cancelling last time because Brian told me too but turns out he lied to me saying he had worked out how to fix it.

Can you please share with me what wiring diagram you found ?! I would like to take a look and maybe print it off at the library and show it to Brian.

Brian says by looking at maf wiring that it looked wrong, can't remember why . Maybe he found a diagram similar to the one you found and the colors were completely different maybe ?

But I would like to see a pic of the diagram you found.

The loom that has been cut I am pretty sure is just the wiring from the MAF to the plug, it is only 2-5 inches from sensor.

I honestly don't understand why you're still taking your car to this guy, given how bad a job he's done at attempting to fix this problem. This diagram shows the pinout of a Ford MAF, and (as I mentioned in a previous post) it shows that there is no 'open loop'. For what it's worth, open loop refers to a type of control system, which is completely different to an open circuit, a distinction that 'Brian' clearly doesn't know about. If it's the wiring on the MAF that's been cut, go and buy a new one, fit it (probably two bolts and connecting a plug, though I'm sure your mate could still balls that up) and see how the car runs.

oh, and what did you mean by

Saying the wiring colours 'look wrong' is a sign of someone well out of their depth. Anyone competent wouldn't be relying on wiring colours for anything more than tracing wires.

please?

the colors of the wiring do matter.

As Talon said, the colours of the wires don't matter AT ALL. They are useful for tracing wires, but in a system as complicated as a car wiring loom it's simply not possible to have a distinct (and standardised) colour for every function. What matters is where the wires connect to, which is why you need to know the pinout for the connectors you're looking at.

What did you mean by Brian performing dangerous work on my car ?

You said he had 'repaired' leaking fuel injectors with superglue and cable ties. Given the pressure that diesel injectors work under, that's an utterly terrible idea (and further proof this guy simply doesn't know what he's dealing with). If the 'repair' fails when someone is working under the bonnet and they get in the way of the diesel jet they will get a hydraulic injection injury - if you want to know more, do a google image search, but I'd suggest you don't have a full stomach at the time. On the other hand, if the failure occurs some other time, you're spraying atomised fuel around the engine space, which is a significant fire hazard.

Reply 13