No power to the fuel pump relay...HELP!...wiring expert needed! - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

91white_ka · 08-21-2009, 11:13 AM

Ok so quickly to get everyone on the same page. I have a 90 hatch shell, with a dohc swap. It's a 5-speed, base model, manual everything.

Let me start of by saying I HAVE NO SOHC WIRING IN THE CAR AT ALL!. Nothing is cut at all,Every piece of wiring is from a 92. Motor is from a 96. I have an S14 upper intake mani. All emissions removed. Windshield squirters, A/c, and emissions wiring is still present in the harness but not plugged in.
Ok so I just rebuilt the motor, and wired the car up. When I turn the key on I get power to the fuel pump fuse, but not to the relay (tested with a multimeter) If I jump a wire from the batter to the "out" prong of the relap the pump comes on and the car runs fine. Any ideas? Thanks.

HAWAII · 08-21-2009, 11:46 AM

change the relay.

91white_ka · 08-21-2009, 12:33 PM

NO POWER TO THE RELAY....so I should place a new relay in this dead slot just to see if that draws power? That's what your saying?

midnightouge · 08-21-2009, 12:47 PM

I had the same problem, it was a loose ground that bolts up to the engine, on top of the header.

91white_ka · 08-21-2009, 01:15 PM

Are you talking about the one that comes off the upper engine harness and has another little secondary ground that goes to the fire wall?

midnightouge · 08-21-2009, 03:58 PM

Yes sir, that's it.

91white_ka · 08-21-2009, 07:58 PM

Wow when I did my wire tuck that ground wouldnt quite reach the mounting spot on the head. So i just mounted it on the firewall. I wonder if that was my problem....I have some extra 4ga wire laying around I'm going to add a grounding kit tomorrow.

91white_ka · 08-23-2009, 09:39 AM

Ok so I pulled my dash, interior, and front clip off to check all my wiring, I found a ground that I had completely missed back by the driver rear strut tower. Still no power to that relay. Pump won't even prime, and cluster is non-working completely. Does anyone know what those relays under the dash mounted to the fuse boxes are?

Also my EGI relay (located just to the left of the fuel pump relay is clicking after I turn the key off.

91white_ka · 08-23-2009, 08:51 PM

cut an extra harness apart today and found the fuel problem.

PS the two prongs closest to the front of the car feed directly from the fuel pump fuse. The purple and black wire goes to the ECU, and the other wire (lower left if your looking at the relay from the side of the car runs all the way to the fuel pump. Hope this helps someone else.

08-21-2009, 11:13 AM	#1
91white_ka Banned from the Marketplace Join Date: Apr 2009 Location: New Orleans, La Age: 32 Posts: 615 Trader Rating: (5) Feedback Score: 5 reviews	No power to the fuel pump relay...HELP!...wiring expert needed! Ok so quickly to get everyone on the same page. I have a 90 hatch shell, with a dohc swap. It's a 5-speed, base model, manual everything. Let me start of by saying I HAVE NO SOHC WIRING IN THE CAR AT ALL!. Nothing is cut at all,Every piece of wiring is from a 92. Motor is from a 96. I have an S14 upper intake mani. All emissions removed. Windshield squirters, A/c, and emissions wiring is still present in the harness but not plugged in. Ok so I just rebuilt the motor, and wired the car up. When I turn the key on I get power to the fuel pump fuse, but not to the relay (tested with a multimeter) If I jump a wire from the batter to the "out" prong of the relap the pump comes on and the car runs fine. Any ideas? Thanks.

08-21-2009, 12:47 PM	#4
midnightouge Zilvia Addict Join Date: Jun 2007 Location: BayArea Posts: 749 Trader Rating: (12) Rides Gallery: midnightouge Feedback Score: 12 reviews	I had the same problem, it was a loose ground that bolts up to the engine, on top of the header. __________________

08-21-2009, 03:58 PM	#6
midnightouge Zilvia Addict Join Date: Jun 2007 Location: BayArea Posts: 749 Trader Rating: (12) Rides Gallery: midnightouge Feedback Score: 12 reviews	Yes sir, that's it. __________________

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08-21-2009, 11:46 AM	#2
HAWAII Zilvia Addict Join Date: Jun 2009 Location: Burbank,Ca Age: 45 Posts: 716 Trader Rating: (24) Feedback Score: 24 reviews	change the relay.

08-21-2009, 12:33 PM	#3
91white_ka Banned from the Marketplace Join Date: Apr 2009 Location: New Orleans, La Age: 32 Posts: 615 Trader Rating: (5) Feedback Score: 5 reviews	NO POWER TO THE RELAY....so I should place a new relay in this dead slot just to see if that draws power? That's what your saying?

08-21-2009, 01:15 PM	#5
91white_ka Banned from the Marketplace Join Date: Apr 2009 Location: New Orleans, La Age: 32 Posts: 615 Trader Rating: (5) Feedback Score: 5 reviews	Are you talking about the one that comes off the upper engine harness and has another little secondary ground that goes to the fire wall?

08-21-2009, 07:58 PM	#7
91white_ka Banned from the Marketplace Join Date: Apr 2009 Location: New Orleans, La Age: 32 Posts: 615 Trader Rating: (5) Feedback Score: 5 reviews	Wow when I did my wire tuck that ground wouldnt quite reach the mounting spot on the head. So i just mounted it on the firewall. I wonder if that was my problem....I have some extra 4ga wire laying around I'm going to add a grounding kit tomorrow.

08-23-2009, 09:39 AM	#8
91white_ka Banned from the Marketplace Join Date: Apr 2009 Location: New Orleans, La Age: 32 Posts: 615 Trader Rating: (5) Feedback Score: 5 reviews	Ok so I pulled my dash, interior, and front clip off to check all my wiring, I found a ground that I had completely missed back by the driver rear strut tower. Still no power to that relay. Pump won't even prime, and cluster is non-working completely. Does anyone know what those relays under the dash mounted to the fuse boxes are? Also my EGI relay (located just to the left of the fuel pump relay is clicking after I turn the key off.

08-23-2009, 08:51 PM	#9
91white_ka Banned from the Marketplace Join Date: Apr 2009 Location: New Orleans, La Age: 32 Posts: 615 Trader Rating: (5) Feedback Score: 5 reviews	cut an extra harness apart today and found the fuel problem. PS the two prongs closest to the front of the car feed directly from the fuel pump fuse. The purple and black wire goes to the ECU, and the other wire (lower left if your looking at the relay from the side of the car runs all the way to the fuel pump. Hope this helps someone else.