Fuel pump just quit Options

[porschetub]

I swapped the relays around but there was no difference. I do have power getting to the relay plate but not working at specific locations it should be after that. I located 2 pins on the T14 connector that work when the key is on and turn off when the key is off. I think one is to the starter or alternator light plug based based on the 73 relay board picture LieroFox posted above. I am going to direct wire to that lead and see how that goes and post back.

Yes, the other ones that comes on with key on is the alternator warning light at Pin 2 (the blue wire) and the back-up lights at Pins 3 and 4 (gray/brown wires)... which I forget which one provides power for that one. I believe it's Pin 3 that provides power, and Pin 4 that goes to the reverse lights.

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Not sure but appears you have a bad relay board,if you can't wire as per the tech article you have issues.I know this as mine was DOA,I ended wiring thru the heater boost fan with a 7.5amp fuse till I got a rebuilt relay board...night and day really,just saying

[surfdogskier]

She now purrs like a kitten. Thank all of you for your help!!!!!

[KELTY360]

She now purrs like a kitten. Thank all of you for your help!!!!!

What was the fix?

[surfdogskier]

She now purrs like a kitten. Thank all of you for your help!!!!!

What was the fix?

I do not know exactly why the fuel pump wire was not activating at the relay board. So I pulled the red/black wire from the plug, stripped it down and put a jumper lead with a round clip. I then picked one of the 2 pins on that plug that turned off and on with the key, placed the clip on it, pushed the plug back on. Now whenever my key is turned on, my pump works and when key is off, it goes off. Simple fix.

[lierofox]

The biggest point of caution I'd give for that solution:

Your fuel pump is now no longer fed by a relay, and the wires coming from the key switch to feed the relay board might cause problems as a result, both from the long path and the fact that they're powering the pump directly instead of switching a small relay coil, depending on the fuel pump you're using that could be between 5-15 amps.

The wire for your fuel pump is also no longer fuse protected, where previously it was protected by the 25a fuse, now there's just a wire going directly from the battery, forward to the ignition switch, over to the un-fused side of the fuse panel, back to the rear again, and finally back to the fuel pump.

[914_teener]

(IMG:style_emoticons/default/thumb3d.gif) (IMG:style_emoticons/default/brain.gif) (IMG:style_emoticons/default/blowup.gif)

[rhodyguy]

(IMG:style_emoticons/default/blink.gif)

[surfdogskier]

The biggest point of caution I'd give for that solution:

Your fuel pump is now no longer fed by a relay, and the wires coming from the key switch to feed the relay board might cause problems as a result, both from the long path and the fact that they're powering the pump directly instead of switching a small relay coil, depending on the fuel pump you're using that could be between 5-15 amps.

The wire for your fuel pump is also no longer fuse protected, where previously it was protected by the 25a fuse, now there's just a wire going directly from the battery, forward to the ignition switch, over to the un-fused side of the fuse panel, back to the rear again, and finally back to the fuel pump.

I thought about that fuse issue. It was a concern. I am going to add a inline fuse in that wire. I just wanted to make sure it would run well first then do it.

[Rand]

I understand the hack to get by. I do that too. But it is TEMPORARY. Don't just skate by on this "solution" please. If you do every fix like this, your car will be a nasty mess devaluating by the second.

[lierofox]

I understand the hack to get by. I do that too. But it is TEMPORARY. Don't just skate by on this "solution" please. If you do every fix like this, your car will be a nasty mess devaluating by the second.

I'm not sure if it's too late now to swap it back to stock or not, but, I'd want to look through the relay board, personally. See where the power is getting lost. Is it getting lost at the Power Supply relay coil? Is it getting lost a the output of the power supply relay? Is it getting lost at the fuel pump relay coil? Is it getting lost at the outlet of the fuel pump relay?

You said in the very first post that there was no power on the switched 12v terminal on the T4B connector, well that 12v comes from the Power Supply relay, so either:

A: +12v key voltage isn't reaching the Power Supply relay (terminal 85)
B: The Power Supply Relay has no ground at the coil (terminal 86)
C: The Power Supply Relay has no power going to its input terminal (terminal 30)
D: The Power Supply Relay has no power coming out of its output terminal (Terminal 87)
E: The Power Supply Relay is just inoperative.

To test the board I'd use a multimeter and test for continuity:
Between Pin 8 on the T14 connector and Terminal 85 on the Power Supply Relay.
Between Pin 10 on the T14 connector and Terminal 86 on the Power Supply Relay.
Between Pin 12 on the T14 connector and Terminal 30 on the Power Supply Relay.
Between Terminal 87 on the Power Supply Relay and Terminal 85 on the Fuel Pump Relay.
Between Terminal 87 on the Power Supply Relay and Terminal 1 on the T4B connector (the top right one labeled Last Resort Unfused Private Switched +12v)

All of those points should have continuity even with the relay board fully unplugged. If all of those test good, I'd test the Power Supply Relay, you could even pull a relay from the headlight motors and swap it in place to test it that way.