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Add an extra ground to your cars fan wire for better power.

Posted: April 30th, 2006, 2:46 pm
by mazdamx3sohc
i noticed as all of you have, that when you turn on your ac with your stock alternator you lose power and your rpms kick up.

i decided to add a ground wire to the wire from the fan and ground it to the frame.

1. Pop the hood, unplug the plug that the electrical coming off the fan is on, on Your left side facing the car.

2. cut the black wire not all the way through, just enough to splice in the new ground wire, the other wire is black and blue striped so you know your at the correct set or electrical wires.

3. wire your new ground cable, i just used some spare wire i found, maybe like around a 12 gauge. tape that whole section back up with electrical tape, so it doesnt get wet.

undo a bolt on the car, i unbolted the bolt on the black piece (that they put the catalyst on) right in front of the plug that you unplug. tighten the bolt with the new ground on it and plug your fan back in. now start the car, turn on your ac, go for a drive, toggle it on and off and see the difference, i think i may have actually noticed MORE power than before overall, slightly.

let me know how this works for you. it really did work good for me.

Posted: April 30th, 2006, 6:54 pm
by zuna_mx-3
On my car, if I change the heater speed or turn on the lights - there is an immediate rpm failure... I should do it soon....

Posted: April 30th, 2006, 6:59 pm
by mazdamx3sohc
it deffinetely made a huge difference, check out my cardomain for pictures. its not as good now, i think they wire might have broke. but its deffinetely a LOT better.

Posted: June 12th, 2006, 11:17 pm
by MrMX3
I read this and really kinda laughed. First of all if you look at the wire sizing, the power wire and the ground wire are both the same size, which means you won't have a current restriction from just your ground wire. Secondly, by splicing into the wire halfway, your still only flowing as much current through the circuit as that first part of the wire will support, so your getting absolutely no benefit there. If you really want to increase it, you need to pull the pin on both the power and ground from the plug and replace it with larger gauge wire, not 2 spliced in half way and then just electrical taped together in hopes it will stay. Thankfully you did this on the ground though so there's less risk of electrical fire. :p

Try upgrading your entire electrical system first. Large gauge ground wires for the battery and block. Larger gauge wire from the alt to the fuse panel, then fuse panel to battery. Not only will that only cost a few bucks, but it will make EVERYTHING electrical in the car work better

Posted: June 13th, 2006, 1:15 am
by mitmaks
MrMX3 wrote:I read this and really kinda laughed. First of all if you look at the wire sizing, the power wire and the ground wire are both the same size, which means you won't have a current restriction from just your ground wire. Secondly, by splicing into the wire halfway, your still only flowing as much current through the circuit as that first part of the wire will support, so your getting absolutely no benefit there. If you really want to increase it, you need to pull the pin on both the power and ground from the plug and replace it with larger gauge wire, not 2 spliced in half way and then just electrical taped together in hopes it will stay. Thankfully you did this on the ground though so there's less risk of electrical fire. :p

Try upgrading your entire electrical system first. Large gauge ground wires for the battery and block. Larger gauge wire from the alt to the fuse panel, then fuse panel to battery. Not only will that only cost a few bucks, but it will make EVERYTHING electrical in the car work better
good suggestion

Posted: June 14th, 2006, 1:45 am
by BuGS
MrMX3 wrote:I read this and really kinda laughed. First of all if you look at the wire sizing, the power wire and the ground wire are both the same size, which means you won't have a current restriction from just your ground wire. Secondly, by splicing into the wire halfway, your still only flowing as much current through the circuit as that first part of the wire will support, so your getting absolutely no benefit there. If you really want to increase it, you need to pull the pin on both the power and ground from the plug and replace it with larger gauge wire, not 2 spliced in half way and then just electrical taped together in hopes it will stay. Thankfully you did this on the ground though so there's less risk of electrical fire. :p

Try upgrading your entire electrical system first. Large gauge ground wires for the battery and block. Larger gauge wire from the alt to the fuse panel, then fuse panel to battery. Not only will that only cost a few bucks, but it will make EVERYTHING electrical in the car work better
Not true. have you ever noticed when you have a long extension cord, how it pulls more amps when you start something up? Unless you are an electrician, or have weak circuit breakers I highly doubt it. By grounding the fan closer to the motor there is less distance the power actually needs to travel, so there is a less AMP pull when the fan kicks on.

Yes upgrading everything is nice, but not needed.

Posted: June 21st, 2006, 2:47 am
by Grants
have you ever noticed when you have a long extension cord, how it pulls more amps when you start something up?
Thats due to the conductor size and volt drop. Typically extension leads have relatively small conductor sizes of 1 - 1.5mm where fixed wiring is more like 2.5mm. So as the volts drop off over distance and load, the amps need to increase to compensate to the load (P (watts)=E (volts) x I (amps)). Theres no use upgrading either the active or neutral wires only, they'd both need to be increased in size for any improvement.

However this isn't really relevant in an automotive sense.

The main problem associated with "dimming" is usually poor grounding. Manufacturers rely on the body / engine for negative return paths and very commonly put in insuffient copper cabling for the grounds. While they're sufficient engineering wise, over time corrosion and movement can increase resistance which impacts on the integrity of the grounding network.
By grounding the fan closer to the motor there is less distance the power actually needs to travel, so there is a less AMP pull when the fan kicks on.
The power needs to travel right back to the negative post of the battery regarless of where a component is actually bolted to the frame. So the path needs to be of minimal resistance all the way back. You'll get no improvement at all if the mechanical and electrical connection is poor between the body and the negative post so there's a good arguement for upgrading all the ground wires.

Posted: June 22nd, 2006, 9:45 pm
by FlyVFR
Long wire runs are more resistive than shorter runs.