86 F-250 7.5 liter with 4brl
Haynes manual electrical diagrams colors are all wrong, configuration wrong too.
So I guess I am asking if anyone else has had this problem with wire diagrams not matching? Where can I find the correct diagram. Also where is the ecm or ecc. I looked all under the dash and cannot find it.

 

I do not think you have an EEC or ECM. You still have something that looks like a Duraspark II control unit that operates with a TFI Module mounted on the side of your Distributor.

I do not think that you will find an after market wiring diagram for it. You will have to get a factory diagram from Helm or one like it off ebay.

I do not think too highly of any of the after market manuals like a Haynes manual. A lot of the posters say get them but I do not know why.

 

Well the haynes manual has served me well in every other aspect of maint and repair but is sadly lacking when it comes to wiring diagrams in my opinion. As for the ecm I am inclined to agree even though the haynes wire diagram shows one. However that may have been referring to the fuel injected models

 

Go to your local library and borrow their "Mitchell Manuals". Nothing beats it.

Many service stations use the CDROM/DVD version, if you're friends with one maybe they'll print out a wiring diagram for you.

86 should not be EFI.

 

my friend has an 86 f250 it has no computer no cat and a carb no fi you have a 460 which was considered a heavy duty truck no emission.

 

Yes correct mine is 460 carb no cats. Haynes says 86 had ecm but does not say it has fi

 

your truck does not have any computer the. F150 that year did but the 250ies did not. fuel injection was why there was an ecm. there for the book is wrong.



Mountaineer man.

 

The Haynes manual I have shows a feedback carb system for the 4.9 liter and the 5.8 liter. It shows fuel injection for the 5.0.

I don't see where it shows the 460 at all for 84-86, except the "hot fuel handling" part of the schematic. So I don't think it's wrong entirely, it just doesn't show it. It's been my experience they only show and highlight the differences of the various years. So you may find your wiring to be more like an earlier year with a carb, except for the fuel pump circuit.

I noticed www.helminc.com has the factory wiring diagrams for your truck for $12.00

 

After looking into this a little your engine wiring is just like a 1982 Ford Truck with a standard Duraspark II Ignition System with no feedback carb system.

You have no ECM for a feedback carb system and the 1982 may have different wire colors but they will be going to right places.

The Distributor is the same as the 82 and has no module on the side.

If you need a Duraspark II Ignition System diagram we can post one.

Good luck.

 

some of the 82 looks right however the 82 doesnt show fuel pump relay or inertial fuel shut off switch. Now new problem. I wrote another thread about this problem in another section of the forum telling of my fuel system woes.

apparently a previous owner had probs with the in tank fuel pumps not working so he put a high pressure fuel pump inline , or the high pressure pump is standard I don't know, but I do know that the in tank fuel pumps were not working. I pulled off the fuel pump relay and took it apart to see if it was working. The insides were all corroded and not functioning. So I replaced it with a new one. Now the in tank pumps are working. I did not realize at the time that they did not stop working. I mean to say that when I put the new relay on that the in tank pumps run with the key off. So after a couple of hours the battery was drained sufficiently so the engine would not turn over. The relay is an exact duplicate of the original so I know I did not get the incorrect relay. Here is the layout. From the starter relay on the hot side I have a yellow wire which leads directly to the inertia switch. The other wire coming from the inertia switch goes to the fuel pump relay. Then there is a red wire also connected to the hot side of the starter relay which runs back to the fuel pump relay. Then there is a pink/black wire coming from the hot when cranking side of starter relay running to the fuel pump relay.

At the fuel pump relay there are two additonal wires one black wire is simply connected to the body of the truck (ground I would guess) There is another wire, black or brown which has been cut. Someone obviously did some rearranging of the wires. It seems to me I should only have one constant hot to the fuel pump relay and the other wire which should provide power to the coil inside the relay should only be hot with the key on. I know the haynes manual says something about the in tank pumps only being activated with the engine running via a signal from the oil pressure switch. I dont seem to have any connection coming from the oil pressure switch unless the power leading from the fuel pump relay travels through the oil pressue switch. In that case it could be that the oil pressue switch is stuck on and the wiring is correct to the relay. I just dont know at this point. I have added a picture of the relay in my album.

 

I do not show you having a pump on the rail.
Here is a diagram of you fuel system.

 

Thank you, that matches what I have, now I can make sure it is wired properly

 

Need wiring Diagram 86 f250 6.9l diesel chiltons has no diesel wiring diagrams,charging system has short.

 

If your truck has an external regulator, it will be wired like this.


If it has an internal regulator, it will be wired like this

 

I have a 86 F 250 with a 460/C6 with dual tanks and carb,no cats, no eec or ecm.Also have the duraspark igintion.I also have a Haynes manual and it doesn't help me one bit so I plan to go to O'Reillys and order a big chiltons manual not the paperback I hope it will cover what I need From it.