fuel pump wiring woes

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polarbytes

Alaska gold Dart
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OK, a couple of disclaimers before I burden all of you with my trials. First, I am a real novice when it comes to auto electrical. Second, this is my first complete rewire of a car. Now the particulars. Car is a 70 Dodge Dart. Wiring kit is by EZ Wire. I have a MAD kit to move the battery to the trunk. I am also using MAD’s junction blocks for battery power under the hood. My problem: I am trying to wire up a Walbro fuel pump to a switch on the dash. The pump has a relay wired according to a member’s suggestions here on fabo. The EZ fuse block has dedicated wire for the fuel pump. Today I accidentally touched this wire to the battery junction block and the engine turned over. I have tested this fuel pump wire for voltage and am not reading anything. Yet there is obviously a completed circuit to the start circuit through this wire. I confess that I am out of my depth on this. EZ Wire really doesn’t include much in the way of instruction and zero info on troubleshooting. I have been trying to reach someone at EZ wire all afternoon but no luck. I should also mention that although I have 12+ to the relay the pump is not activating which is why I was messing around with the fuel pump wire in the first place. Sorry for the length of the post but I know more info is better when trying to solicit help from the more knowledgeable.
 
The pump wiring via relay is pretty simple. Here is the power and pump connection.
1. 12v (from your fuse block most likely) goes to one of the contact connections of the relay.
2. The other contact connection of the relay goes to the + side of the pump (probably a red wire).
3. The other connection of the pump goes to a ground nearby.

The control side is:
4. One side of the relay coil to ground.
5. The other side of the relay to one side of the control switch.
6. The other side of the control switch goes to 12v.

What relay do you have?
 
polarbytes said:
..............The EZ fuse block has dedicated wire for the fuel pump. Today I accidentally touched this wire to the battery junction block and the engine turned over..
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you may have to enlist local help. I'm only guessing. Sounds like you fed power TO that wire, by touching the junction block, and the "other end" somehow engergized the starter.

Might be something you did, or a wiring mistake

One thing I REALLY dislike about most ALL the aftermarket stuff regardles of brand is that the do NOT have a good complete diagram of what the harness "really is" and how it interfaces with the fuse panel. I set down with mine and traced every single wire. Some of them were repurposed,..........such as power windows, and some were re-wired at the fuse panel to be on with "only ignition" or with ACC , etc.

What you need to do is figure out what that wire is and where it goes, .....in the harness

and secondly, figure out "how" you hooked it so to run the starter.

Can you post a link to the EZ destructions, and specifically "which wire" you are referring to?
 
While there are many words to read, it is not possible to pull the information to help you with the wiring. The mention of terminal blocks, wire, relay... what is important is how they are connected. To show connections, a wiring diagram is often used. A diagram is worth 1000 words. If you can draw a diagram, we can better help. Just start with boxes with terminals, and show connections.
 
Well, thanks for the quick responses. I'm not really asking for help on the wiring, I already have the car wired and it starts. What prompted my question was the wire that came out of the EZ wire fuse block labeled "fuel pump" that I inadvertently touched to the positive lead from the battery and the car turned over. I am concerned because as 67Dart273 alluded I may have a shorted wire in the fuse box because that fuel pump wire should not be activating the start circuit. 67Dart273 there is no good instruction from EZ on line. They have minimalist manual which is not worth much. If I had it to do over again wouldn't use EZ Wire. KitCarlson, I am overly verbose, but am to old to change. nm9stheham, thanks for that info but I'm pretty sure the relay is wired right. I'm guessing now that because of the screwy voltage on the EZ wire harness that's the problem. I can apply 12v direct to the pump relay circuit and get the pump to run. It's how I got fuel to start up initially. I guess that I will have to go through the EZ fuse block wire by wire. Again, thanks all for the help.
 
I may have the EZ book saved somewhere, have to look

The one I have they are calling "17 circuit" but I see nothing in there about an electric pump
 
Sometimes the writing on the wire isn't what it really is, DAMHIK!
 
67Dart273 said:
I may have the EZ book saved somewhere, have to look

The one I have they are calling "17 circuit" but I see nothing in there about an electric pump
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I have the 20 circuit one. I could just bypass the pump wire, remove the fuse, but I am concerned that it is shorted to the start circuit and that could cause problems down the road. If you find your manual and it has a schematic that would be great.

Cracked, yep, that is a distinct possibility. BTW, your headlight wiring kit works like a champ!!

I do have a real nice five relay box from a guy who custom makes them. Got his info on another wiring thread a while back. I could just use one of those relays.
 
I would not have a manual. The only one I had was the 17, which came up somewhere via email, etc. Sorry.
 
I am trying to be helpful, it is not about being verbose. It is about providing information about your present connections. Only you know that, you hooked them up, hopefully with a plan. The plan must include an understanding of completing an electrical circuit, so current flows when switch is closed.

Most relays have 4 terminals when used in a normally open situation such as running a fuel pump. Two are for the coil, two for the contacts, that close when coil is energized. The 12V pump fuse block wire, might or might not be interlocked with ignition switch. Incorrect connection there, may be what cranks the engine.

Wiring is more than hooking up wires and noting what happens.
 
KitCarlson said:
I am trying to be helpful, it is not about being verbose. It is about providing information about your present connections. Only you know that, you hooked them up, hopefully with a plan. The plan must include an understanding of completing an electrical circuit, so current flows when switch is closed.

Most relays have 4 terminals when used in a normally open situation such as running a fuel pump. Two are for the coil, two for the contacts, that close when coil is energized. The 12V pump fuse block wire, might or might not be interlocked with ignition switch. Incorrect connection there, may be what cranks the engine.

Wiring is more than hooking up wires and noting what happens.
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I am sorry if I came across as flippant. I do appreciate your expertise and willingness to help. And yes, I agree wiring is all about a plan. I made a detailed list of what I was going to do before I started on this project and as much as I was capable, noted where my wires were going. I do have the benefit of some excellent auto wiring books but first hand knowledge is always a plus in my opinion. I hope I never stop learning from others. So,
I am going to pull the fuse panel out of the car and take a look at it. And the relay does appear to be working correctly. I have it wired in to the 12v start circuit and it activates with the key on start. I was just trying to use the fuel pump wire from the fuse panel to wire in a momentary switch.
 
polarbytes said:
I have it wired in to the 12v start circuit and it activates with the key on start. I was just trying to use the fuel pump wire from the fuse panel to wire in a momentary switch.
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Adding a switch is best done in series with the relay coil. The idea of the relay is delivering a low impedance supply as direct as possible to the load, without extra wiring and switch on the load side. The coil side is low current, so smaller wire and additional switch will not harm the actuation of the relay. Not sure if the mystery fuel pump wire, fits into what I suggest.
 
KitCarlson said:
Adding a switch is best done in series with the relay coil. The idea of the relay is delivering a low impedance supply as direct as possible to the load, without extra wiring and switch on the load side. The coil side is low current, so smaller wire and additional switch will not harm the actuation of the relay. Not sure if the mystery fuel pump wire, fits into what I suggest.
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Well, mystery solved! A close examination of the fuse panel reveals that the fuel pump wire is in fact a switched circuit. Obviously I should have done a little more research before wasting so much bandwidth.My thanks to all who so graciously responded. And thanks KitCarlson for your explanation of some basic wiring knowledge.
 
polarbytes said:
Well, mystery solved! A close examination of the fuse panel reveals that the fuel pump wire is in fact a switched circuit. Obviously I should have done a little more research before wasting so much bandwidth.My thanks to all who so graciously responded. And thanks KitCarlson for your explanation of some basic wiring knowledge.
Click to expand...

That does not make sense. Why would that cause the starter circuit to engage? Or were you simply on the wrong track somehow?
 
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