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Fuel pump not turning on

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Old 10-06-2011, 08:26 AM   #1
Sleeper90
 
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Default Fuel pump not turning on

My fuel pump won't turn on when I turn the key to the on position. I have researched the fp relay and replaced, replaced the fp and the solenoid and fixed the gr/yl wire which changes to or/bl before getting to the solenoid. The previous owner rigged the pk/bk wire coming out of the fp relay to have constant power through the fuse panel, this caused my fp to run constantly and to prime constantly. I put the pk/bk wire back where it was suppose to go but now I don't know where the pk/bk wire goes. I think it goes to the ignition switch but not 100% sure. I have pics of what I'm talking about. Any help would be appreciated


http://i264.photobucket.com/albums/ii186/dllundgren/photobucket-4149-1317905953514.jpg




http://i264.photobucket.com/albums/ii186/dllundgren/photobucket-4091-


http://i264.photobucket.com/albums/ii186/dllundgren/photobucket-4449-1317905916528.jpg1317905930780.jpg
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Old 10-06-2011, 07:32 PM   #2
Bubba 95SN
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Veryuseful.com will show wiring
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Old 10-08-2011, 08:20 PM   #3
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It would be on a circuit that has battery power when the key is in the on position.
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Old 10-08-2011, 09:39 PM   #4
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The pink/black wire is a 12v constant source that has a fusible link. That is the wire that powers the pump when the key on 12v power engages the relay. I don't remember which connector it goes to....

The fuel pump is supposed to prime until the PIP signal is received by the ECU and then it kicks off. The previous owner obvious bypassed a deeper issue.
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Old 10-08-2011, 10:26 PM   #5
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Thanks for the responses. I have actually taken the dash off at this point. Not only because of this issue but I have to do a heater core replacement, alarm system removal, just seeing what the h3ll others have done, etc. The most recent discovery is the lack on connectivity between the pin 19 wire (pk/bk) at the EEC and the wire at the fuel pump relay also pk/bk. Is there a fuse, fuse link, connector etc between the EEC and the quick connect that is behind the fuse panel on the drivers side?
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Old 10-09-2011, 05:56 PM   #6
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On 10-6 11 I gave you what you needed. Very useful.com has color wiring diagrams. If you had taken the time here is the correct answer...pk/blk goes to inertia switch then on to power the fuel pump.
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Old 10-10-2011, 02:57 AM   #7
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Bubba 95SN, I already looked at those diagrams, and multiple others, none show what I wanted to know, hence the second question. Either way, I've test multiple options and now am at a lose. The only two things not replaced at this point are the grounds for the vehicle and the EEC. These are the only two options left. My EEC is giving 6 volts when the key is in the ON position. It has 7 volts when the engine is on. I have tested the grounds at the solenoid, under the EEC, block to frame, and a couple of others, all are tight, any appearances that looked shady to me, such as a junk splice have been redone so I've all but ruled out ground issues. If the EEC is bad I would think pin 19 would get no volts and other things would be wrong with the vehicle. Any suggestions, rumors, outbursts, etc???
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Old 10-10-2011, 08:13 AM   #8
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If you cant find what you need from those wiring diagrams, you should bring the car to someone who understands schematics... because this is clearly over your head
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Old 10-10-2011, 06:42 PM   #9
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Well, thanks for the opinion, AdderMk2. My question is clearly too complicated, I'll try another site.
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Old 10-10-2011, 07:51 PM   #10
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I'll take a peek at my diagrams tonight when I get back.
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Old 10-10-2011, 08:22 PM   #11
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Thanks mattdel. I've looked at veryuseful.com and multiple other diagrams. These are great for general knowledge of where the wire runs. However, they do not tell all the connectors, grounds, splices, etc that I need to diagnose. For instance one diagram shows two pk/bk wires coming out of the fp relay, this is false, there is actually a splice just under the carpet to the right of the drivers seat if facing from the front of vehicle. This splice had been taken apart in the past and put back together loosely by a previous owner. I reconnected it properly but this was not the answer to why my fuel pump does not turn on when I put the key to the acc/on position.

I did find out the EEC is only suppose to have 6 to 7 volts at pin 19 at any given time. Ford technician from church told me. Next step for him would be the CCRM....
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Old 10-10-2011, 08:34 PM   #12
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There is no CCRM on a fox....

Try this link...about half way down is a no fuel condition and shows some in depth stuff...

http://sbftech.com/index.php?PHPSESS...17&topic=588.0

You know you could also pull the dash and start tracing the wire yourself and take out the days of you checking this site for new info...
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Old 10-10-2011, 09:02 PM   #13
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Thanks, I'll go through that stuff and double check. I've done most of it, not in that order but looks good thanks.
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Old 10-10-2011, 11:20 PM   #14
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K, so here's what my diagrams show. (All references to LH/RH assume you're in the drivers seat.)

The pink/black wire that runs from PIN 19 of the EEC to PIN 5 of the relay has two connectors along the length of the wire.
C207 is inside the LH cowl panel.
C213 is inside the RH cowl panel.

Check for continuity between PIN 22 of the EEC (Tan/Light Green) and PIN 1 of the FP Relay.
2 connectors along that circuit as well, to check for incase of no continuity.
C203 again inside the LH cowl panel.
C110 is LH rear of engine compartment.

The Orange/Light brown wire on PIN 3 of the relay has an 18 gauge brown fuseable link.
Make sure the red wire incoming to the inertia switch has 12v.
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Old 10-11-2011, 01:03 PM   #15
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Thank you, you're a gentlemen and a scholar. I will check all of this tonight.
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Old 10-15-2011, 11:40 AM   #16
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Still, nothing...... at fp relay, Power to gr/yel wire constant 12v, red wire 12v when key turned to acc, pk/bk wire 6v when on acc, tan/bl wire 0v at all times....

Under the hood the tan/bl wire is not connected to anything, it is sitting right next to the self test connecter with multiple holes, this is the way the tan/bl wire should be correct? I couldnt find anything obvious to connect it to so I assume.
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Old 10-15-2011, 12:17 PM   #17
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leave the wire alone. that is the one you connect a jumper to along with the self test plug to read your codes. If you had the cover for the plug it would fit into it.
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Old 10-15-2011, 12:27 PM   #18
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That's what I thought but wanted to make sure

thanks
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Old 10-16-2011, 04:19 PM   #19
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That 6v value is odd. Sounds like a bad ground to me. Should be 12v.

The powertrain management ground circuit for the fuel pump is PIN 57, grounded out behind the RH cowl panel. Black wire.

Also, PIN 49, an orange wire, is a ground as well. Passes through connector C119, at the top RH side of engine, then grounds to G109, also RH rear of engine.
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Old 10-16-2011, 04:46 PM   #20
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I will definitely check those grounds. Thanks for the info.
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Old 10-16-2011, 04:46 PM
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1990, 199050mustangfuelpump, 50, eec, fuel, fuseable, gt, inertia, link, location, mustang, priming, pump, relay, switch, turning

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