The Yellow wires go to the fuel pump relay.
But also the fuse box, Ignition Switch and Power relay have yellow wires going to them.

Fuse link M goes to the Fuel Pump Relay:


/

 

Thanks Bill!!!! thats exactly what i need

Larry

 

Bill What and where do fuseable links L, F,G do and go to???

Thanks again Buddy

Larry

 

L is th BK/O wire:



F & G you may not have:


/

 

Thanks buddy!!!

Larry

 

Bill also could you tell me where and what fusible links W, N, J do and go to also
Thanks bill

larry

 

Also Bill what type of fusible link do i buy? the ones with the FuseLink at the eyelet where it attaches to the positive side of the starter solonoid? or the ones with the fuselink in between the two wires in the middle. On some of the wires there is a block where it splits from one wire to 2 wires. Is this block the fuselink or is it the block next to the eyelet the fuselink??
Thanks buddy
larry

 

W as seen in the above image 17 goes to fuse #1 in the fuse panel.

N goes to the power relay:


J BK/O wire goes to the alternator as seen in image 15 above.

For fuse links just buy a roll of fuse link wire of the right gauge for what it is protecting and crimp connectors on it.

 

Bill - i think i finally have this truck sorted out!!!! Thanks again for all your help especially w/ the schematics youve sent

friends forever

BigLar

 

Well i spoke too soon again!! im back to square one with this Friggin truck again. Im just at my wits end to why this truck will run 40 to 200 miles and then start acting up. Im going to purchase a MOTORCRAFT hall effects sensor and install this on my dizzy. Im telling you i have checked wire grounds,wires,relays until im sick. Ive also ordered new eec and fuel pump relay sockets. If i decide to purchase a remanufactured ECM does anyone have any suggestions?? Napa-ecm togo-etc: Also any tricks to get the ECM out of my truck would be greatly apprieciated.

BigLar

 

I think the 88 comes out from inside the cab.
Unplug it under the hood and then take the drivers kick panel off and take it out.

 

well bill i just put in a new Hall effect sensor"motorcraft" and a new TFI module "motorcraft" and SOB this truck does the same thing - runs good for about a minute then stumbles and dies with NO fuel pressure. Im starting to think ECM at this point !!!. Any suggestions on whose a good builder or supplier of remaned or rebuilt ECM`s???

Thanks buddy

Larry

 

I can not help you on that.
I use a salvage yard when I need one. I keep a spare on hand and tested so I know it is good when I put it in. So far I have never had one of mine go out yet but have a lot of tested spares.

Some members have said they bough computers from auto part stores and have had to take them back three times to get a good one.

 

Hi Bill im still screwing around with this truck!! i havent touched it in about a month now and i did as you suggested and removed the ECM. When i plugged the ECM back in,yes i did get spark but now the starter solonoid just clicks and the motor wont turn over. Jeez what a mess. since we last posted i have soldered in new EEC and Fuel pump relays, Checked every ground known to man and bought a noid tester to see if the injectors pulse which they do. Still NO fuel pressure though. Im sending the ECM out to be rebuilt or a remaned ECM which ever is needed. Can you explain the problem with the starter solonoid???? it just clicks away when i try and start the motor yet the battery is charged fully.The motor turned over prior to removing the ECM!!!! Im about ready to give up. Im in the middle of Moving right now and i really need this truck to be reliable

Thanks Bill

Larry

 

larrylass:

I have an 88 F350 dually with a 460 and dual tanks. Both tanks leaked when I purchased the truck and I replaced both of them along with the in tank pumps, although the old pumps still worked. It just made sense.

Within a month, both new in tank pumps went bad. At the same time. Still under warranty, NAPA replaced them for free. Now a second time, both in tank pumps have gone bad. Again, at the same time! I have power all the way to the in tank pump plug, the 4 wire one, on both tanks. I can jumper the pumps to attempt to turn them on (I unplug the high pressure one on the rail, it works and is also new) but no sound from the in tank ones. No sound from either in tank pump.

I removed the front new in tank pump, and bench tested it, on a battery, and it is indeed dead. Gauge still works on both front and rear. When I plug in the old pump, the one that came with the truck, into the trucks plug, at the tank, it works. The in cab switch works great and the resouvior is a new one from Ford.

Are the aftermarket in tank pumps just junk? I have read you had bad experience with them. I have now had 4 give up the ghost, 2 front and 2 rear. Did you ever find out why your rear pump went bad at the same time the front one did, because that is what happened to me on BOTH sets of in tank pumps. Truck just seems to burn up the aftermarket pumps is the only thing I can think of. But the same day? Both pumps? Both times?! I ordered two new Ford pumps for in both tanks and it really hurt the wallet, and I hope this stops the madness. I now have more in parts than I paid for the truck easily.

I understand by reading your lengthy posts with subford and Zion that you just had a bad new front in tank pump, but what about the rear? Why was it not working?

Thank you.