MX-3.com

I searched in this forum for this topic... I found one article, but they not explain how to add the fan ...
they finished talking about water cooling tubes or something like that...
so if someone could tell how exactly i could add 1 fan o 2 i dont know... to my amp that is in the back of the rear seat of my mx-3 i would appreciate it... thanxz!

you just really have to get one or tweo pc fans and if a way to attach them. i used zipties, after that just wire them to the ground cable from the amp and the power you'll get from the remote turn on wire that why it's only running when the amp is on.

hope that helps

reaper
greg

the power you'll get from the remote turn on wire

You have to be a little careful when doing this. If your remote wire is from your headunit then it probly can only output 250mA, 40mm fans take 100mA a piece. I origionally hooked my fans to the remote, but the head unit was straining to put out enough power to that wire and a ton of noise spoiled my music. It's better to use the remote wire to trigger a relay, which will then turn on both your amp and the fans.

to my amp that is in the back of the rear seat of my mx-3

It would be nice to know the exact setup. Unless the amp is enclosed it should be able to self cool itself. Esspecially if it's a 2ohm stable amp running at 4ohms (or similar situation).

You'll need a Bosch style relay and a relay wire harness (check partsexpress.com). Use the remote turn-on wire from the headunit to the turn on wire of the Bosch relay. Wire up a regular power output to the relay's main power. Wire the relay output to a couple 12 volt computer fans.

lakersfan1 wrote:You'll need a Bosch style relay and a relay wire harness (check partsexpress.com). Use the remote turn-on wire from the headunit to the turn on wire of the Bosch relay. Wire up a regular power output to the relay's main power. Wire the relay output to a couple 12 volt computer fans.

Actually, since we're dealing with such small current we can cheat a little.

5 Volt relays are WAAY cheaper than 12 volt relays. The downside is they can only handle 1 amp at 24volts, but since you can run 2 amps and 5 fans using 1amp of power, that shouldn't be a problem. The only thing is you need the correct resistor to create a 7 volt drop, stepping the relay voltage down to 5v. For my setup the relay was 56 Ohms, so I used a 78 Ohm resistor. If yours has a different value then just divide 7 by the optimal current (which should be on the back of the packaging) and that is the value resistor to use. All these parts can be picked up for pocket change at radiocrapshack or any other parts store.

A Bosch relay is $1.20. You did all that to save $1????

I did it because I already had the parts and a 5v relay is the size of one of my pinky joints (~1 square centimeter). Overall It costs less and takes up less space, two things I like.

Either way will works tho.

ok... sorry for making too many questions, but i'm new in this car audio stuff ..!
So.. i have some questions...

-how i get the 12V cable? I extend it from the head unit?
-I put a fuse between the star of the 12 volt cable and the relay, another fuse for each fan and another fuse before reaching the amplifier?
- the first fuse is with the sum in amps of the 2 fans and the amplifier and the fuse of the fans are the amps of each fan, and the fuse for the amp is the amps of the amplifier...?

I HAVE A MAYOR PROBLEM ONLY WITH THE FUSES:?:? I DONT KNOW WHERE TO PLACE THEM... mmm well with the 12 volt cbale too.. i dont know where to get this cable..

and what kind of cable should I use for this kind of conections... its cause i dont want to see my car in fire

jorgesamaniego3 wrote: -how i get the 12V cable? I extend it from the head unit?

Exactly. Splice into the power wire of the headunit (yellow wire). If it's an aftermarket HU then you can put the splice right into the wire adapter. ((note: this is just for the remote line.. the actually power for the amp should be it's own system using a dedicated wire which should be fused 6in from the battery))

-I put a fuse between the star of the 12 volt cable and the relay, another fuse for each fan and another fuse before reaching the amplifier?

If you are tapping the HU powerline, then it's already fused, you don't need to do anything. One fuse is enough.

and what kind of cable should I use for this kind of conections... its cause i dont want to see my car in fire

The remote line should be 18-22g (roughly). It isn't running much power, so it can be small.
The power line for the amp should be around 4g (depending on how much power your amp eats). There is a lot of power running through it, so it needs to be big.


Don't forget to disconnect your battery durring all of this.

This might be a simpler connection with the 12v relay

sorry for butin in but if you are running the amp properly you should never need a fan if its shuting itself down its two week for the speakers or you are pushing it to hard and are libel to fry it with or without a fan.
if you can make it look cool more power to you though