1985 LTD LX/Marquis Wiring Diagram Needed. THANKS, IT RUNS!!

[BLUEMERC]

I am having trouble getting the electric fuel pump to run and I am not sure which wires to hook up to the ignition module red/white wires. This is after the switch from 3.8CFI to 302Carbed. I ripped out ALL the wiring from the ECM. There are also some "extra wires" that are not identified by the Chiltons and Haynes manuals I have. The thing is this close(thumb and fingers almost touching) to running! I just REALLY need this last little bit of help!

Thanks,
BLUEMERC

[Chuck W]

Well what are you using for the FP wiring? The existing stuff should work as it's all there anyway. However, when you pulled the ECU wiring, did you also jank the ECU relay? What about the FP relay?

If you pulled the ECU relay, the FP relay will not energize.

Where is the new fuel pump being mounted?

If it were me I would try and make use of the existing FP circuitry so as to maintain the inertia switch.


Sorry I can't help on the wiring diagrams....don't have any for that year.

[Marz]

I have an 1985 LTD LX/Marquis Wiring/Vacuum Diagram book. Unfortunetly, I do not have a scaner hooked up right now so I'll have to snap a photo of it with my digital camera. But I'm at work right now so that will have to wait till I get home.

[BLUEMERC]

Marz, that would be GREAT!

Chuck, I yanked out the complete wiring harness from the ECU including sensors, solenoids, relays and the ECU itself. Where are the relays located for the pump? I am using the stock electric pump with a holley fuel regulator and return line. I have one three-pin connector located next to where the ECU mounts that has a large yellow wire, a small red and a small tan w/green dots. Does this go to the pump and inertia watcha-ma-callit? Would 12V to all three get things going?

Thanks,
BLUEMERC

[Chuck W]

That should have been where the ECU relay plugged in. I'm not certain where the FP relay is...on my Tbirds it's in the trunk and is green. the ECU relay is brown. Do you have a pic of the connector?

Test for voltage on the pins. The two smaller ones will be the "switched" or engergizing circuit(red would be 12V in start/run and the tan/lg would be the ground from the ECU) and the yellow should be the 12V from the battery. You should have a 4th wire though to go to the fuel pumps.


Oh wait, looking at an 83 wiring diagram, those 3 wires come together in the same connector, but it appears the inertia switch is wired after that.
Do this.
First check for voltage at the yellow wire. Let me know if it's hot or not all times. If not you need to run 12V to it from the battery (be sure to fuse it). Next check the red wire and see if it has 12V when the key is in run and start. If not, run a 12V switched source to it. Then run the tan/lg wire to a good chassis ground. This will energize the relay when the key is turned on.
I imagine the FP relay is still in the car towards the back and you just need to get power to it and this connector is the key to it all.

[Marz]

On my LTD LX the fuel pump relay is in the trunk on the passengers side and behind those fancy cardboard/carpet stuff.

The inertia switch is right next to it.

[Chuck W]

If that's the case, then he probably just needs to get power to the yellow (12V batt) and red (12V switched) wires and ground the tan/lt green one and he should be set if those items are still in their locations.

[BLUEMERC]

CHUCK, YOU ARE THE MAN!!!

Just had the pump running a couple of minutes ago! Still need to find out what all the "extra" wires are for so I can decide what to do with them. Also curious on the ignition module red and white wires if they need individual feeds or can I just wire them together with a wire that is hot in both start and run?

Thanks,
BLUEMERC

[Chuck W]

It's been a while since I did a Duraspark car...

However looking at an old manual

Red wire ---> 12V in START
White wire ---> 12V in RUN

If you didn't pull ALL the wires out from under the hood there should be a connector for the old ignition stuff near the driver strut tower that has a White/L Blue Hashed wire and a Red/L Blue wire. The wh/lb H is 12V START and the red/lb is 12V RUN.

[Marz]

Heres a few pages from the 85 LTD EVTM. All are for a 5.0L. I hope this helps you...

http://www.hostunlim.com/Marz/P2270011s.jpg

http://www.hostunlim.com/Marz/P2270013s.jpg

http://www.hostunlim.com/Marz/P2270014s.jpg

http://www.hostunlim.com/Marz/P2270015s.jpg

[BLUEMERC]

Thank You guys! You are GREAT!!!!!!

I hope to have some time tommorrow to put the diagrams and suggestions to work.

BLUEMERC

[Chuck W]

I was hoping Marz would post up the page that shows the ignition section to see the wiring from the ignition switch to the ignition module(pg 21)

I know that rd/lg wire is spliced with the w/lb H wire and is 12V start.

There should still be a connector there though in the driver side engine bay with the proper wires you are looking for.

[Marz]

I was hoping Marz would post up the page that shows the ignition section to see the wiring from the ignition switch to the ignition module(pg 21)

I know that rd/lg wire is spliced with the w/lb H wire and is 12V start.

There should still be a connector there though in the driver side engine bay with the proper wires you are looking for.

Sure thing... I can do that... but it'll be later tonight.

[BLUEMERC]

On the drivers side right near the brake booster are:

Two pin connector one Black, one White w/Black stripe

Four pin connector Large Gray w/Yellow stripe, Large Red w/Light Green stripe, small White w/Pink dots, small & Large Red w/Blue stripe

On the drivers side about one foot forward of Brake Booster are:

One Pin Connector Black

Six Pin Connector Large Gray w/Yellow stripe, Red w/White dots, Green w/Yellow dots, Red w/White stripe, Black w/Yellow dots, one blank


BLUEMERC

[Chuck W]

Well, that large red/lb stripe wire should have 12V w/ the key in run and either that Wh/lb H or the large red/lg should have 12V with the key in start.

Check those out.

[BLUEMERC]

I believe I checked them earlier and they BOTH are hot in start and Run.
If so would it matter which one was wired to what?
I will double check later tonight.

BLUEMERC

[Chuck W]

I can't say for certain. I would try and find the "correct" wires though. They're there, you just need to figure out what's what.

[Marz]

Ok... this is how my LTD LX works with it's two pumps.

You will hear the pumps in run... then when you move the key on over to the start position the car starts and the the key is back in the run position with the pumps running. But if the key is kept in the run position without moving the key to the start position to start the car the pumps will run then turn off after a few seconds.

I hope I explained the two where it's understandable.

It seems to me that the pumps are suposto be hot in both the run and start positions. But there is a protection timer in the circuit that will turn the pumps off if the key is in the run position with out the car running.

[Chuck W]

Right the pumps are supposed to be hot in START and RUN, and the info I gave earlier on that is what he needed to use that 3-wire connector to use the existing wiring and get the fuel pumps powered.

Now we are looking for the wires for the ignition module. He needs one hot in START and one hot in RUN. If you can copy that page (21), it should show what he needs for that.

[Marz]

Some more pictures....

http://www.hostunlim.com/Marz/P2280016s.jpg

http://www.hostunlim.com/Marz/P2280019s.jpg

http://www.hostunlim.com/Marz/P2280020s.jpg

Hope this helps.

[Chuck W]

On the drivers side right near the brake booster are:



Four pin connector Large Gray w/Yellow stripe, Large Red w/Light Green stripe, small White w/Pink dots, small & Large Red w/Blue stripe



BLUEMERC

Well, the 85's look to be a little different. Looking at hs first pic there (pg 21)

Connect the R/lb (large) to your Red wire and connect the R/lg to the white. THe r/lb is hot in start and the r/lg show it could be hot in both start and run, but I don't think I would connect them both to the r/lg wire.

[BLUEMERC]

I checked out the wires with a voltmeter. This is what I found:

HOT at Start Only............ small White w/Pink dots

HOT at Run Only............... Large Gray w/Yellow stripe(two locations)
.................................... Medium & small Red w/Light Blue stripe

HOT at Start & Run........... Large Red w/Green stripe
..................................... small Red w/White dots
..................................... small Red w/white line

Always HOT...................... small Green w/yellow dots

Looks like small White w/Pink dots for White wire on Ignition Box and
Large Gray w/Yellow stripe for Red wire to Ignition Box since it is closer than the Red w/lb.

Thought it would be running tonight but we had dinner guests.
HopefullyI can get it going Friday night, Saturday afternoon at the latest!


BLUEMERC

[BLUEMERC]

IT RUNS!!!!!

Thanks to ALL who helped! It started up and ran very nice. I didn't drive it around any but it moved on its' own power from the driveway into the garage! Will need to make the wiring permanent and put the dash back on(changed the heater core). I went thru some periods where I thought I might NEVER see it run again. Can't wait to take it out Sunday afternoon.

THANK YOU AGAIN!!!

BLUEMERC

[Chuck W]

Glad you got it going

[David Claflin]

Heres a few pages from the 85 LTD EVTM. All are for a 5.0L. I hope this helps you...

http://www.hostunlim.com/Marz/P2270011s.jpg

http://www.hostunlim.com/Marz/P2270013s.jpg

http://www.hostunlim.com/Marz/P2270014s.jpg

http://www.hostunlim.com/Marz/P2270015s.jpg

Where did you get the wiring diagram at?? I'm looking to find a good one for my 85 LTD, to help with the EFI conversion...