Wiring experts

WTFWSAT · 11-08-2011, 05:59 PM

I noticed a few days ago that the relay plugs for my fuel pumps are getting hot enough to deform the plastic. I have fuse pigtails coming off the battery that are 12 gauge wires with 20 amp fuses that go to the relay. On the 87 pin going to the pump the wire is about 4" of 12 gauge then butt connected to 10 gauge all the way to the pump. This is the pin that is deforming the most.

Also in the pic attached i have the 30 and 86 pin straight to the battery. I know the 86 pin should be on a switched 12v source but the big stuff 3 uses the ground pin 85 to control the pumps. Is there a better way to use the relays since my on/off switch is through the ground pin?

Could the relay pigtail wiring being too small? Do i need to ditch the pigtails and just run bigger wires to the relay?

Thanks

WTFWSAT · 11-08-2011, 06:00 PM

Should have put this in the tech section. Mod feel free to move.

Darryl Buckner · 11-08-2011, 06:35 PM

I am no expert, but I can't see where it is wired wrong. Your box is just controlling the relays with a ground activation, and thats fine. Even 12ga wire should be good for 20 amps no longer than your car is. However impedence changes like 12ga to 10ga wire through a butt connector, will cause heat. I would soldier it together and make it all 12ga or all 10ga wire. Also check your relay sockets, the prefab ones we get here usually only have 14ga wire in the sockets, and 20amps on 14ga wire is pushing it..

WTFWSAT · 11-08-2011, 10:10 PM

Quote:

Originally Posted by Darryl Buckner

I am no expert, but I can't see where it is wired wrong. Your box is just controlling the relays with a ground activation, and thats fine. Even 12ga wire should be good for 20 amps no longer than your car is. However impedence changes like 12ga to 10ga wire through a butt connector, will cause heat. I would soldier it together and make it all 12ga or all 10ga wire. Also check your relay sockets, the prefab ones we get here usually only have 14ga wire in the sockets, and 20amps on 14ga wire is pushing it..

Thanks Darryl,
I just checked the sockets and they are either 14 or 16 gauge, along with the fuse holders so im pretty sure thats one issue. Funny i bought a "30amp" fuse holder and it comes with 16 gauge wire?

I think im going to replace the fuses with circuit breakers so i can run 10 gauge wire and make my own sockets.

Is there a local place to buy the relay plugs and wire ends for them?

Paul they were actually 30 amp fuses i was mistaking.

SC-both pumps were checked out by aeromotive with in the last year but i would still like to know what kind of amperage they are pulling. I only have a Fluke 115 but im going to check the book and see if i can check amps with it.

Thanks

Lurch · 11-08-2011, 11:23 PM

I purchaced a Dual lug crimper which is said to be as good a solider. It crimps the lug twice, I have used it in high amp draw applications and it seems to work well if you would like to borrow it call me Mitch 843-696-7004

Darryl Buckner · 11-09-2011, 10:35 AM

Quote:

Originally Posted by Lurch

I purchaced a Dual lug crimper which is said to be as good a solider. It crimps the lug twice, I have used it in high amp draw applications and it seems to work well if you would like to borrow it call me Mitch 843-696-7004

Nothing against crimping connectors, but they are not allowed in my shop because alot of the police vehicles and such we work on have computers and such. Believe it or not you can read with a meter the impedence change in the wire by crimping that metal barrel in between the 2 wires, and impedence changes cause heat. Soldiering the wires together shows no change and will never corrode and break apart over time. Granted he is dealing with fuel pumps and not computers, but I would steer away from crimping wires espicially outside a vehicle where its exposed to weather..

1iron · 11-09-2011, 08:57 AM

Quote:

Originally Posted by WTFWSAT

Thanks Darryl,
I just checked the sockets and they are either 14 or 16 gauge, along with the fuse holders so im pretty sure thats one issue. Funny i bought a "30amp" fuse holder and it comes with 16 gauge wire?

I think im going to replace the fuses with circuit breakers so i can run 10 gauge wire and make my own sockets.

Is there a local place to buy the relay plugs and wire ends for them?

Paul they were actually 30 amp fuses i was mistaking.

SC-both pumps were checked out by aeromotive with in the last year but i would still like to know what kind of amperage they are pulling. I only have a Fluke 115 but im going to check the book and see if i can check amps with it.

Thanks

Circuit breakers are what the instructions call for as well.

Darryl Buckner · 11-09-2011, 10:40 AM

Quote:

Originally Posted by WTFWSAT

Thanks Darryl,
I just checked the sockets and they are either 14 or 16 gauge, along with the fuse holders so im pretty sure thats one issue. Funny i bought a "30amp" fuse holder and it comes with 16 gauge wire?

I think im going to replace the fuses with circuit breakers so i can run 10 gauge wire and make my own sockets.

Is there a local place to buy the relay plugs and wire ends for them?

Paul they were actually 30 amp fuses i was mistaking.

SC-both pumps were checked out by aeromotive with in the last year but i would still like to know what kind of amperage they are pulling. I only have a Fluke 115 but im going to check the book and see if i can check amps with it.

Thanks

Chris,

I have everything in stock pretty much for 10,12,8ga stuff, if you need it. The unfortunate thing is you will have to hardwire the relay with larger wires, which is pretty easy, because the premade sockets I keep in stock, I have never found any with wires larger than 14-16ga. Give me a shout if you need help..

WTFWSAT · 11-09-2011, 11:47 AM

Thanks Darryl,
I should have some of the spade connectors around the house, if i cant find what i need ill give you a call. And i do plan on soldiering the connections.

1iron · 11-08-2011, 08:06 PM

Aeromotive says 30amp and 10ga.

schardbody · 11-08-2011, 09:34 PM

how old is the pump?

you need to see what kind of amperage it is drawing.

i didnt look at the wiring diagram because it hurt my eyes, but if it checks out check the pump.

chrisheltra · 11-09-2011, 01:11 PM

Oh I forgot to mention I agree with everything else Darryll said. Especially the part about resistance and differing wire sizes.

Harry · 11-09-2011, 02:13 PM

I do have a crimper at work that I would trust. 12 ton hydraulic crimper. Doesn't work on anything below #6 though.

11-08-2011, 06:00 PM	#2
WTFWSAT Senior Member Join Date: Nov 2007 Location: Summerville Posts: 861	Should have put this in the tech section. Mod feel free to move. __________________ Fastest stock computer 5.0 on the planet! Looking for cheeep msd 6al! PM me! 88 Coupe (turtle) 03 Cobra (tortoise)

11-08-2011, 06:35 PM	#3
Darryl Buckner The Top Dog Join Date: Dec 2007 Posts: 2,318	I am no expert, but I can't see where it is wired wrong. Your box is just controlling the relays with a ground activation, and thats fine. Even 12ga wire should be good for 20 amps no longer than your car is. However impedence changes like 12ga to 10ga wire through a butt connector, will cause heat. I would soldier it together and make it all 12ga or all 10ga wire. Also check your relay sockets, the prefab ones we get here usually only have 14ga wire in the sockets, and 20amps on 14ga wire is pushing it.. __________________ When the people fear the government, there is tyranny. When the government fears the people, there is liberty. Thomas Jefferson

11-08-2011, 11:23 PM	#5
Lurch Moderator Join Date: Jan 2007 Location: Goose Creek SC Posts: 554	Wire and crimpers I purchaced a Dual lug crimper which is said to be as good a solider. It crimps the lug twice, I have used it in high amp draw applications and it seems to work well if you would like to borrow it call me Mitch 843-696-7004

11-09-2011, 11:47 AM	#9
WTFWSAT Senior Member Join Date: Nov 2007 Location: Summerville Posts: 861	Thanks Darryl, I should have some of the spade connectors around the house, if i cant find what i need ill give you a call. And i do plan on soldiering the connections. __________________ Fastest stock computer 5.0 on the planet! Looking for cheeep msd 6al! PM me! 88 Coupe (turtle) 03 Cobra (tortoise)

11-09-2011, 01:11 PM	#12
chrisheltra Neo is Jesus Join Date: Jan 2007 Posts: 13,265	Oh I forgot to mention I agree with everything else Darryll said. Especially the part about resistance and differing wire sizes. __________________ Gap A Hoe Racing

11-08-2011, 08:06 PM	#10
1iron Senior Member Join Date: May 2007 Posts: 2,014	Aeromotive says 30amp and 10ga.

11-08-2011, 09:34 PM	#11
schardbody Senior Member Join Date: Sep 2008 Posts: 1,158	how old is the pump? you need to see what kind of amperage it is drawing. i didnt look at the wiring diagram because it hurt my eyes, but if it checks out check the pump.

11-09-2011, 02:13 PM	#13
Harry Senior Member Join Date: May 2008 Location: Summerville Posts: 3,321	I do have a crimper at work that I would trust. 12 ton hydraulic crimper. Doesn't work on anything below #6 though.