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Dreaded fuel pump wiring


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About: 89 SWB Pioneer, auto, 96/97 HO with all Renix components to include harness. Things I’ve done so far, open cooling system, several ground refreshes, replaced fuel filter, o2 sensor, replaced spark plugs, replaced PS pump, VC, Oil pan, RMS gaskets, cleaned TB, IAC, TPS,gauge cluster swap, headlight relay harness and bed lined the interior and redid the headliner.

 

Where I am now is the comanche has been sitting for a little while. It has started dieseling. So I’ve decided to run it hard for a few times and try to clean some carbon out.

 

But before that I want to redo the fuel pump relay. The PO has hardwired it with a hot wire from the ACC pin on the fuse block. Bypassed the ballast and wired in the efan to a vac harness. The question is which orange and black wire is from the ECU and which one goes to the pump. One of them will trigger the pump with the key on the other one does nothing. I have messed with the OEM relay and nothing happens. It doesn’t die or stall.

 

Thoughts are to run a stand-alone relay in place and run a fuse to the battery, then connect to the wires I have exposed. fa811dd8b1fd444304d617329170fa93.jpg

 

 

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RADIO fuse is what protects that ACC outlet. Happy PO didn't up the amp rating on that fuse. This set up runs Fuel Pump motor current thru the IGN SW, thru RADIO fuse, out ACC outlet and then to Fuel Pump motor. It actually taps a different Fusible Link. On the Starter Relay is the ORN/BLK wire connected to the BAL terminal? Also check condition of all your fusible links. Green ones in particular.

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RADIO fuse is what protects that ACC outlet. Happy PO didn't up the amp rating on that fuse. This set up runs Fuel Pump motor current thru the IGN SW, thru RADIO fuse, out ACC outlet and then to Fuel Pump motor. It actually taps a different Fusible Link. On the Starter Relay is the ORN/BLK wire connected to the BAL terminal? Also check condition of all your fusible links. Green ones in particular.

So that would sort of explain why the Truck shut off while driving on the hwy several months ago. I lost radio, wipers, signals, and interior lights. Just overload on the ignition switch. I replaced that with new and replaced the fuses and everything was good than. I did try to pull each relay with the truck on with no change. What is the the BAL terminal?


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Removed he power wire from the 2 orange and black wires for the Ballast. Connected them to the ballast an no start. No fuel. Did the relay dance with the 4 next to the battery. Still no start. So the next question is, is the ballast bad? Everything works with the bypass. All the connections look good and the ones that were questionable were cleaned.

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Initially the ballast was bypassed. But I want to add a level of protection for piece of mind with a relay. I want to take the power off the ignition switch and out of the fuse block. I’ve been stranded 2times, both with the fuse block and the circuits inline with the hot wire to the “bypass”

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2.3ohms is double it rating. Either bad ballast or that just the way the meter reads. If you go to buy a new ballast bring meter with you. Measure new ballast at the store. Same reading, don't buy it.

 

Myself, if everything works fine with the ballast bypassed leave it like that (til new ballast, if needed). Easy for me to say since it not me stranded in the center lane on the highway during rush hour traffic.

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