'85 Tbird fuel pump or pumps, relays location

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'85 Tbird fuel pump or pumps, relays location

June 18, 2015, 07:38:24 PM

Probably answered this a million times, but here we go again.

1985 TBird V8 302, replaced the carb based injection system with an eddy carb, etc etc. I purchased a bypass 3 connection fuel regulator to monitor the higher fuel pressure from the stock electric pump(s) to a carb. It is designed just for this application. Now I have read that it is possible that this car might have 2 pumps, (high pressure out of tank pump and the lower pressure in tank pump), but I also read that this particular TBird year came with only one pump in the tank. I see conflicting evidence with this and hope this can be answered with facts.

*If this car has 2 pumps, where can I locate the high pressure frame rail pump, if it has a 2nd pump at all.
Apparently the 2 pump factory installation ended in 1984 and in 1985 went to a single high pressure pump in tank.

*Next, where can I locate the computers EEC computer fuel relay connection that powers the pump relay and does anyone know what the wire color combination is that would need to be bypassed from it's stock 12v (key on)connection to a new (key on only) connection?

UPDATE: located fuel pump relay in trunk left drivers side

I plan on also installing a power cutoff switch as well between the relay and the 12v power source to turn the system off in case I have to diagnose (key on) issues in the future or secure it from being driven, for example...theft.

'85 Tbird fuel pump or pumps, relays location

Reply #1 – June 19, 2015, 12:51:23 AM

There should be a fuel inertia switch right by the relay, one wire in and one back out that you could easily wire in a anti theft switch to, hidden in the trunk, or simply use the inertia switch.

If the eec relay is in the Sam location as the 86 up efi cars, it is in the dash hidden up by the glove box. Somehow the brown eec relay triggers the fuel pump relay. Not sure if it is through the computer or separately.

From what i remember, the dual pump setups had an external pump in a similar location to the fuel filter at the rear frame rail right infront of the passenger side wheel.

'85 Tbird fuel pump or pumps, relays location

Reply #2 – June 19, 2015, 09:15:37 AM

MY 85 XR-7 only has the tank-mounted pump. My 83 5.0 had the two pumps though (one in the tank, one on the frame rail). I had to move the external pump to make room for dual exhaust. I would say the easiest way to find out is to follow the fuel lines and see where they go. The external pump isn't hidden, it's pretty obvious.

'85 Tbird fuel pump or pumps, relays location

Reply #3 – June 20, 2015, 06:31:06 AM

evtms below in my sig,,
the eec relay is easy to follow / trace

you should have a safety switch already like said, ford put the fuel pump relay and inertia switch in the trunk in a couple places. most everybody has the relay up on pass side hinge, inertia sw on wall behind license plate. there is a white button you lift up on to disable / enable the fuel pump

'85 Tbird fuel pump or pumps, relays location

Reply #4 – June 21, 2015, 01:12:25 AM

Only the 87-88 cars have the inertia switch in the light panel area. My 86 was inches away from the passenger side hinge, and most fox mustangs had them in the interior somewhere.

'85 Tbird fuel pump or pumps, relays location

Reply #5 – June 21, 2015, 07:42:19 AM

I found some info on this stuff...
My switches seem to be in the trunk,
Apparently fuel pump relay is located above the inner rear right side fender in the trunk.(have seen this in the trunk)

There is an inertia switch (relay) located exact opposite of that switch on the driver's side in the trunk, I think this is what it is.

Looks like according to this info I posted, the eec fuel power relay is passenger side kick panel area.

From what I have found so far on the fuel pumps, my 1985 has only the high pressure pump in the tank, though the '84 does have 2 pumps. I located the fuel filter and tracked back to tank and there is no 2nd pump on this '85 TBird.

Now my only problem so far now is...can I jumper the eec fuel power relay to initialize the fuel pump relay to pump fuel? I have read that the tan wire needs to be grounded on the eec power relay so the computer thinks fuel is being sent. Though I have no tan wire on this eec module, but there is a tan/lt. grn wire on relay. I have checked the wire specs on both eec power relay and fuel pump relay and broke down both sets of 4 wires on each. Any electrical Einstein's out there know which might be jumped to bypass (fool) the computer into thinking it is powering the pump would be helpful.

EEC Power Relay
1) Blk-yelo = voltage output
2) Blk-lt. grn = Grnd
3) Red-lt. grn = Power from ign. switch
4) Blk-org = Always hat fused power

Fuel Pump Relay
1) Tan-lt.grn = Fuel pump Relay
2) Red = Power from EEC Relay
3) Pink-blk = Fuel Pump Output
4) Yelo = Ign. fused power (fuel pump fuse)

'85 Tbird fuel pump or pumps, relays location

Reply #6 – June 21, 2015, 10:56:46 AM

Hello

As far as 2 pumps verse 1 pump....ford made a big switch in Feb 85....so early 85's(ie fall 84 builds) have 2 pumps and after that 1 pump in the tank....hope that helps....

Travis

'85 Tbird fuel pump or pumps, relays location

Reply #7 – June 23, 2015, 08:34:33 AM

Fox Mustangs (87-93) fuel pump inertia switch is mounted in the trunk to the sheet metal that the driver tail light is attached. The fuel pump relay is under the driver seat from 87-90 but was relocated to in front of the passenger shock tower in the 91-93 models. On the 87-90 Mustangs there was only one relay in front of the passenger shock tower and that is the WOT cut off relay for the AC so in the 91-93 cars there will be two relays in this location.

I only posted this so that if anyone needed to rob relays or inertia switches they would know where to look.

Darren

'85 Tbird fuel pump or pumps, relays location

Reply #8 – June 23, 2015, 02:23:25 PM

Easy way to run fuel pump is from EEC test plug, ground terminal marked fuel pump...
Yes that should be tan wire, though most models use tan w/green stripe wire... Basically it's pin 22 from ECM...

'85 Tbird fuel pump or pumps, relays location

Reply #9 – June 23, 2015, 03:07:06 PM

Here is where the fuel pump relay and inertia switch are in the '84.

'85 Tbird fuel pump or pumps, relays location

Reply #10 – June 24, 2015, 08:12:56 AM

or back at the fuel pump relay itself you can ground the tan light green, its the same conductor as up at the eec self test conn, it ties into the same wire which then goes to eec pin 22

'85 Tbird fuel pump or pumps, relays location

Reply #11 – June 24, 2015, 08:18:42 AM

don't mess with the EEC power relay up near the computer,, if when the key is turned on it clicks and sends out power on the contacts, its doing its job.

'85 Tbird fuel pump or pumps, relays location

Reply #12 – June 27, 2015, 08:40:26 AM

Quote from: jcassity;449163

don't mess with the EEC power relay up near the computer,, if when the key is turned on it clicks and sends out power on the contacts, its doing its job.

Maybe... If contact is burned/broken relays can click and not provide any power...

'85 Tbird fuel pump or pumps, relays location

Reply #13 – June 28, 2015, 08:51:20 AM

"if it clicks and sends out power"