1986 F350 - 460 7.5L - in-tank or in-line fuel pump

[Gary Lewis]

UPDATE 1:

Went under the hood today. Tracked down fuel pump power (pink/black) and it goes to a connector which splits into two (2) pink/black wires, one thicker than the other (Picture 1). This one goes left to what I'm guessing is a relay (I have very little experience on this) near the hood hinge (Picture 2). In fact dont know what any of the three parts in Picture 2 are.

The thinner pink/black, and a yellow wire, loop along the front to the passenger side and into the cabin, where I found this hanging (Picture 3). Inertia switch? Something rattles inside. It was close to where the arrow points.

Here is where it gets messy. Behind the battery the pink/black and yellow reach a connector where the pink/black ties into a blue wire with a fusible link, but the blue wire is cut (Picture 4). So I know the switch in the cabin is disconnected.

But the one that concerns me even more is back on the driver's side. The pink/black wire, that should loop to the passenger side, has a jumper (red wire I'm holding in Picture 5) going into a red wire in another branch. Don't know where that other red goes or what it does, so again any input is appreciated.

So I dont know if the oil pressure and inertia switches are in the loop or not. Quite sure In need to take the red jumper out and reconnect the blue wire, but is there any troubleshooting/testing in between?

In the mean time, took bench seat out, pulled old vinyl, gave frame wire wheel and rust converter. Got sliders loose and oiled but missing a spring and wire that connects both sliders' mechanisms. But guess I'll leave that for another thread.

You've found part(s) of the problem. Your blue wire is Fuse Link S in the schematic below, and that may not reconnect very nicely, but you will need it. From there the yellow wire goes to the inertia switch, which is bad. From that the yellow wire runs to the relay you pointed out, which is the fuel pump relay.

From there the pink/black wire goes to C120. The pink/black coming in from the top is from the ignition switch which gives the pump full battery voltage in Start. Otherwise it gets reduced voltage due to the .75 ohm resistor.

So you need to figure out why the blue fuse link was cut and replace the inertia switch. And more? The red wire? I got lost there.

[ramses]

You've found part(s) of the problem. Your blue wire is Fuse Link S in the schematic below, and that may not reconnect very nicely, but you will need it. From there the yellow wire goes to the inertia switch, which is bad. From that the yellow wire runs to the relay you pointed out, which is the fuel pump relay.From there the pink/black wire goes to C120. The pink/black coming in from the top is from the ignition switch which gives the pump full battery voltage in Start. Otherwise it gets reduced voltage due to the .75 ohm resistor.So you need to figure out why the blue fuse link was cut and replace the inertia switch. And more? The red wire? I got lost there.

Well that’s a start. Thanks Gary. Having trouble finding inertia switch online. Is there a part number

 

Also, where is the oil pressure switch located?

 

Ramses

 

 

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From: Gary Lewis [via Bullnose Enthusiasts]

Sent: Friday, April 17, 2020 8:13 PM

To: ramses

Subject: Re: 1986 F350 - 460 7.5L - in-tank or in-line fuel pump

 

 

 

You've found part(s) of the problem.  Your blue wire is Fuse Link S in the schematic below, and that may not reconnect very nicely, but you will need it.  From there the yellow wire goes to the inertia switch, which is bad.  From that the yellow wire runs to the relay you pointed out, which is the fuel pump relay.

 

From there the pink/black wire goes to C120.  The pink/black coming in from the top is from the ignition switch which gives the pump full battery voltage in Start.  Otherwise it gets reduced voltage due to the .75 ohm resistor.

 

So you need to figure out why the blue fuse link was cut and replace the inertia switch.  And more?  The red wire?  I got lost there.

 

 

http://forum.garysgaragemahal.com/file/n57183/909962.jpg

 

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 in front & 10.25 Spicer/Trutrac in back, & EEC-V MAF/SEFI

 

 

 

 

 

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[ArdWrknTrk]

The oil pressure switch is at the center back of the engine block, behind the intake manifold.

It should be attached below the oil pressure sender, which is a little tin can looking thing with a wire on top.

[ArdWrknTrk]

Test the inertia switch first.

It may be fine.

Connect a multimeter to each side, hold it upright and press the reset button.

[Gary Lewis]

Test the inertia switch first.

It may be fine.

Connect a multimeter to each side, hold it upright and press the reset button.

I've added the inertia switch to a tab called Part Numbers here: Documentation/Fuel Systems/460 Fuel Systems. But for simplicity and ease of use:

[ramses]

I've added the inertia switch to a tab called Part Numbers here: Documentation/Fuel Systems/460 Fuel Systems. But for simplicity and ease of use:

Thanks guys. Now, how do I know if the fusible link in the blue wire is good. Just test continuity?

 

 

Sent from Mail for Windows 10

 

 

From: Gary Lewis [via Bullnose Enthusiasts]

Sent: Saturday, April 18, 2020 8:32 AM

To: ramses

Subject: RE: 1986 F350 - 460 7.5L - in-tank or in-line fuel pump

 

 

 

I've added the inertia switch to a tab called Part Numbers here: Documentation/Fuel Systems/460 Fuel Systems.  But for simplicity and ease of use:

 

http://forum.garysgaragemahal.com/file/n57222/9A340_&_9341.jpg

 

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 in front & 10.25 Spicer/Trutrac in back, & EEC-V MAF/SEFI

 

 

 

 

 

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[Gary Lewis]

Two things. First, to test the fuse link you'll have to see if there is voltage on the side pointing toward the starter relay on the fender. Then you'll have to see if the other side connects to the inertia switch w/o going to ground. If so, then you could solder the two ends of the fuse link back together.

Second, while it is your thread and you can do whatever you want, if when replying by email you'd click the three dots shown below and delete all the extraneous baggage, meaning the previous comments that are in the response, your thread would be a lot easier to read.

[ArdWrknTrk]

Two things. First, to test the fuse link you'll have to see if there is voltage on the side pointing toward the starter relay on the fender. Then you'll have to see if the other side connects to the inertia switch w/o going to ground. If so, then you could solder the two ends of the fuse link back together.

Second, while it is your thread and you can do whatever you want, if when replying by email you'd click the three dots shown below and delete all the extraneous baggage, meaning the previous comments that are in the response, your thread would be a lot easier to read.

I wouldn't solder the fuselink back together.

Just install a new one.

Cheap enough, and you know it's right.

[ramses]

The oil pressure switch is at the center back of the engine block, behind the intake manifold.

It should be attached below the oil pressure sender, which is a little tin can looking thing with a wire on top.

Hi Jim. Are the oil pressure switch and sender parts that should be replaced? Meaning, are they prone to wear. Just want to make sure to dot all i's and cross all t's.

[ramses]

Two things. First, to test the fuse link you'll have to see if there is voltage on the side pointing toward the starter relay on the fender. Then you'll have to see if the other side connects to the inertia switch w/o going to ground. If so, then you could solder the two ends of the fuse link back together.

Second, while it is your thread and you can do whatever you want, if when replying by email you'd click the three dots shown below and delete all the extraneous baggage, meaning the previous comments that are in the response, your thread would be a lot easier to read.

Hey Gary. Sorry for that. Hadn't noticed that would happen replying by email. I'll try testing that tomorrow.

Mean while, would you know which connector this is?

Just odd to find these two bare contacts bit they seem to fit and its the only open plug in the area. This second picture shows were the contacts lead from.