questions about m1-atx

z32_vg30dett_z3 · 01-08-2006, 02:22 AM

i have my carputer installed using an epia m board with the m1-atx power supply. i wired the switch wire of the m1-atx to an ACC part in my car which is a Mazda3. i also bought an auxmod which allows direct sound input to the head unit (by faking the HU out thinking its playing a tape).

first of all, when i turn to ignition key to start the engine my cpu shuts down. i thought the power supply is supposed to take care of that.

secondly i hear hissing from the computer through the cars speakers. (some power wire near audio wire?)

Please help me.

muldrick · 01-08-2006, 08:22 AM

Quote: Originally Posted by z32_vg30dett_z3

first of all, when i turn to ignition key to start the engine my cpu shuts down. i thought the power supply is supposed to take care of that.

Sounds like you have the M1 power wire hooked up to a source that is not 12volts when the key is in the start position. It needs to be hooked up to 12volt constant/allways 12volts

Quote: Originally Posted by z32_vg30dett_z3

secondly i hear hissing from the computer through the cars speakers. (some power wire near audio wire?)

Check your grounds, and search the forums related to this. Certainly a ground problem though.

Bugbyte · 01-08-2006, 11:10 AM

As Muldrick said, use a multimeter to measure the voltage going INTO the M1ATX while someone starts the car. If it drops to zero, you've got it hooked to a power source that is cut out while the car is starting.

The best way IMHO to hook it up is to wire it directly to the battery (remember to fuse it close to the battery).

Gearhead61 · 01-08-2006, 05:24 PM

What size/amperage fuse should be used?

z32_vg30dett_z3 · 01-08-2006, 10:25 PM

using the jumper settings shouldnt it survive engine cranks tho?...
i am using a 12 volt source (used multimeter on install and thats why i picked that wire) but it must be cut during engine start (where m1 should take over right?)...

but i also found a problem. connected J11 (+) to the 12 volt source. J13 (-) to ground. and J12 to nothing... so the m/b was powering up directly off battery power. ignition had nothing to do with it.

so i should connect the SW (j12) to the accessory (switched 12 volt source) and the J11 to battery (either directly with fuse or a different batt source wire in the car)... right?

z32_vg30dett_z3 · 01-08-2006, 10:31 PM

acutally i got it figured out... i am going to use your recommendation to go straight to the battery (damn it now i have to find a hole in the firewall...heh)

but the reason why the m1 wasnt taking over is cuz the power ot the psu was being cut during engine start. so it couldnt supply power to the m/b until the 12v source turned back on... thats why jumpers werent working either. k... so i understand now... thanks a lot for all your help... it should work now

99blkprotegelx · 01-08-2006, 10:48 PM

Do you have automatic transmission? If so there will be a white plastic cover in the firewall right beside the brake. This is for a clutch pedal...just drill a small hole through it.....if your not up to this..there should be a big black rubber grumit directly beside the white cover.