Quick electrical question
 

Yeah i know you guys get this a lot...

BUT im just wandering what the spec of the headlight relay is...

My "original" one is burend out and on it it states that its for up 22amp's but im jsut wandering if i can chuck a 20amp one there thats not an original replacment (mazda familia relay)a s brand new they cost about 90NZD :S

Anyway thanx in advance :)

ps. ive searched the forum the manual and the haynes book and cant findanything... :S

$90! Holy crap...

You best bet would be to find an OEM replacement from a wrecker. A common 30A relay would probably work fine, but OEM relays are best.

yeah quoted from mazda.. and i dont plan on geting an OEM but just any hadlight relay will do... just wandering what the specs on it are? just so i dont get one thats too low amp rated and fry it aswell... :S

Radio Shack sells one with a 30 amp load side rating, 12v control, for about 5 bucks. I used one on my old MG Midget because the factory ran the full headlight current throught the switch on the dashboard. Works great.

Yeah problem is im in NZ not USA... lol

but thanx for the tip :)

I just want to know what the factory spec is... anyone.. ? :)

Go OEM...According to the schematics, that relay has an internal diode to prevent electrical backfeeding from the headlight switch. Might be hard to find an aftermarket replacement. Besides, if you go Mazda, she's plug 'n play, no cutting & splicing wires :)

haha im going with mazda but just not mazda rx7 way...

:P

I noticed this too, and is why I figured using OEM relays is best. But I guess it couldn't be too hard to solder a diode to the relay's coil contact to give the same effect. The downside of using OEM relays is that you have to choose between an expensive new one or a 15yo one. A new $5 30A relay and a 5c diode sounds pretty good... ;)

But isnt 30 amps a bit of an over kill as far as i can theres only a 12amps current going through it?

Pretty much all the 12V automotive relays available from auto parts or electronics shops are rated at 30A.

Yah, that's the right route to go. The diode is there to prevent arcing between the relay, and the light switch, as the relay is turned off (it's called a flyback diode). Any robust general purpose rectifier diode will probably work, but I'd go with a 1N4004 (less than $0.10 US, and easy to get).

Just remember, that the diode needs to be oriented properly. With most (all) diodes, the lead with the band closest should be pointing towards the light (as shown in the FSM). If you don't do this correctly, you'll probably blow the diode, and/or a fuse.

Menace - The extra load rating really makes no difference, as long as it meets the minimum. It's not as though it's taking up extra space or anything, it just has heavier duty contacts on the load side. Maybe it uses a smidge more current on the control side, but it'll be insignificant.

I've moved my battery to the storage bin, and my fusebox to the glovebox

i also want to move all the relays inside too, too reduce the size of the harness going to the engine bay.

will 30A automotive relays be enough, will they overheat or anything in the cabin?

putting the relays will reduce the wires running into the engine bay as i have a power and trigger wire running into the engine bay for each relay. If i relocate them to the cabin, i will only have the power wire running to the engine bay.

thank you