Just finishing up my Haltech install, and I need to find a switched power (only powered when ignition is on) wire underneath the dash for my gauges. This wire also needs to be positive. I tried looking at my Mazda workshop manual wiring diagram, but I only became more confused. The car is a 10 AE.

If anyone can give me a colour and wire bundle to look for, I would be very appreciative.

thanks,
Kris

 

Why not just tap into your ingition wire for your stereo?

 

unfortunately the previous owner decided to remove the factory stereo, install some other stereo (and do a hack job of installing it), then rip it all back out before I got it. So the wires are all horribly mangled and I cannot get any readings with my voltmeter.

Any other ideas for power?

 

The wire for the stereo is not ignition... it is accessory, it drops while cranking, and is hot in the first (accesory) position. You could not use that wire.

There are two ignition wires coming from the ignition switch. A Black/White, which is true ignition and Black/Red, which is a second ignition (but the B/R also drops voltage while cranking, but at least it is on only when the key is in the On/run position).

Mazda uses Black/White as the feed for the factory gauges. It does switch to a Black/Yellow after going through the fuse box and to the actual gauges themselves.

So you could either tap the large gauge Black/White coming down from the ignition switch, making sure you put a 5 amp fuse within a couple of inchs of your tap.

Or you could use the Black/Yellow at the back of the factory gauges and at the fuse box. To confirm you are on the right wire, when you remove the gauge/meter fuse you will loose power if the key is in the on position.

Remember there is the off, accessory, on, and crank positions of the key.

 

when I was looking for a wire for my amp, I just used the power windows signal (I don't have them). Are there any options that the 10AE doesn't have? Look for those in the fuse box.

 

Stereo amplifiers of over 20 watts a channel should be ran directly to the battery.

Using the fuse box wiring for anything bigger than 20 watt a channel can over load the fuse box wiring. Remember even the power window operation is only a momentary current draw... unlike most stereo power amps.

 

Ouch man, get that amp wire out of the fuse box!

The black and white wire that Icemark is talking about should be very easy to find. Take the steering column shroud off and it should be right there at the ingition. Or you should be able to find it in a clump of large gauge wires under the dash.

Also please fuse the connection! It is better to be safe than sorry!

 

the amp only has a 30 amp fuse, and the connection was designed for a 20 amp. Also, I'm not running subs, I just have 6x9's in the compartments, and, since I never listen at a loud volume, I think I'm pretty safe. Those speakers would shatter before my amp hit 30 amps anyway.

 

thanks again icemark.


Can we be sure this goes in the archives

 

The fuse box connection for the power windows was designed for a MOMENTARY surge up to 22 amps (110% draw is what is required to blow a ATC fuse).

But not a continues draw of 15 amps (half of a 30 amp peak draw amp would use). Again the circuit is designed for windows that only operate at a 1% duty cycle while the car is operating (in other words, the windows are only using that draw when they are working which is a very small amount of time when compared to the vehicle or even stereo is operating, the wires are under-gauged for the very reason.

You will damage the fuse box wiring as well as you are compromising the ability of the amp to reproduce sound without distortion.

It’s your car, but I know for a fire hazard reasons alone; I would never connect a amp or stereo as you have suggested you did.