I have a 1985 F150 w/5.0 MPFI and am having wiring problems, specifically a ground problem.
1) Where to locate an accurate wiring diagram. Mitchell's and All-Data are a no go. All-Data is hard to navigate and primitive. Mitchchell's diagram for 85 F150 5.0 has several wrong color codes on diagnostic connection and EEC. Ex: #1 wire to EEC is actually yellow not violet (per Mitchell's). None of the wire color codes on diagnostic connector (per Mitchell's) match my vehicle. Mitchell's wiring diagram for 86 F150 comes closer, but still not dead on.
2) Mitchell's has no table listing physical ground locations. These things can be located anywhere. Anyone know where they are?
I've found ground wire to body at L.H. headlamp, ground lead from battery neg. to wiring harness, and battery to engine ground (at battery neg. terminal)
Where does battery neg. lead that goes into wiring harness go? Is there a common ground for EEC and if so where?
Getting really frustrated. Next step is taking the truck apart.

 

I believe there is a ground from the battery to the EEC harness, and it has a connector in it that likes to corrode.

I see you are using a lot of third party wiring diagrams. Why not get the Ford diagrams? They have all the info you need. You can buy them new if they are in stock at http://www.helminc.com. You might be able to find them used on ebay.

 

Where is the physical location of the connector?

 

The link that you shared apparently isn't in operation anymore. Just comes up with Solaris and nothing else.

 

Here is a Ford Diagram for 302 with EEC-IV TFI-IV with EFI.

http://i447.photobucket.com/albums/q...VEEC-IV50L.jpg

 

That's interesting. The company that is the authorized publisher for Ford, Honda, GM, etc. is gone. They are either having trouble with their site, or possibly something more serious is happening behind the scenes.

 

On wiring diagrams--color code on diagrams don't match my truck. Color codes on the following are incorrect.
1) diagnostic test connector
2) TFI connection
3) Fuel pump relay
Did they use different wiring harnesses for different assembly plants? Can't find wiring diagram that matches. Impossible to trouble-shoot system.
Need info on where grounds are physically located.

 

Is there a possibility that this could be a truck manufactured in Canada? How would I find that out?

 

On the diagnostic connector my diagram shows;

black/white as a common power wire

tan/red goes to the computer

tan/lightgreen is the fuel pump wire

white/red is the single wire to trigger the test

 

No they didn't use different wiring harnesses.

There have been cases where wire colors have been off on certain trucks to the official diagrams.

My Ford Diagram above (posted earlier) matches what Franklin2 is saying here.

Easiest is to look at the vin number. If built in canada it will have the first three positions as 2FT

If USA, 1FT

 

One of the real problems with the 85-86 5.0L EFI is the entire EFI harness grounds at a two pin connector by the battery that is part on the original ground cable. It corrodes and you lose the ground. The wires in the harness are black with a light green stripe. I would find them where they plug in and put a ring terminal (solder it) on each and connect them directly to the battery negative terminal. This is from my 1986 EVTM. I chased a ground issue on one of these for a week before determining it was that plug, it is C101 on the diagram.

 

My guess is web server problems; Solvaris is a Web technology company, my guess is Helm is using their products and updating/reconfiguring their systems.

I'd try again tomorrow.

 

Do you mean a single pin connector? One pin in each end of wire? Actually mine is a spade or blade connector. Don't really see a need for connector. Simple splice would do.

More info on grounds. There is one at the rear of block near fuel rail connector, one going to a bolt on wiper motor, and a third that has a connector to a wire that goes into the wiring harness. This last one has a connector that isn't water proof and will likely corrode. Cleaned and reassembled with Di-electric grease.

 

It is two wires with a rectangular plug/socket near the battery negative terminal. A splice will do nicely, just be sure it won't corrode from the battery fumes. The ground for the EEC was what you had asked about, that was the one I addressed. The grounds on these are pretty bad, the entire front harness other than the EEC grounds inside the cab on the firewall, The engine to body ground wire is the one to the wiper motor stud. I no longer have the 86 EVTM, I gave it to Archion.

 

Sunday afternoon/evenings are frequently used for maintenance on servers. I agree with Chris - try again tomorrow.