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Mx5 Alternator wiring
Bunje - 22/2/16 at 01:08 PM

hi there
i have a problem with my mazda alternator draining my battery when the car is off. its a mk1 1.6 engine so the alternator regulates its own voltage. three wires on my alternator main one to the battery one which is to the charge light which i dont have anything coonected to as i have a digidash that monitors the battery from the circuit its plugged into and then the other wire which i assume is the sense wire i connected this directly to the battery. i dont have the mazda loom its a westfeild chassis loom with a zetec engine bay loom everything else works fine it even charges when the engine is running at 14.4 volts. but i carnt work out why its discharging the battery i did the parasitic draw test and its drawing .16 which i assume is 16mah but if i remove the sense wire the number goes back to zer so its definitly this causing the drain
can anyone help me out
cheers ben


Smoking Frog - 22/2/16 at 01:25 PM

Have look at this other thread http://www.locostbuilders.co.uk/viewthread.php?tid=200757. It may be your meter is reading 0.16A = 160mA which is too high.
I'm also using that alternator here's the wiring diagram I using.
Charging Circuit
Charging Circuit


Bunje - 22/2/16 at 02:07 PM

I did see your post in the other thread. It's slightly different to what I have because I don't have the original loom it's actually the westfield zetec engine bay loom and I have added the sense wire and the charging light wire in myself


Bunje - 22/2/16 at 02:41 PM

do you have the standard loom or are you using a different one


theconrodkid - 22/2/16 at 07:45 PM

the white / green in the diagram needs to be ignition controlled not straight to the battery,thats where your draw is coming from.


Bunje - 22/2/16 at 08:29 PM

Oh right ok. I'll look into putting it into the ignition switched circuit then
Cheers