solenoid/wiring question...

just a couple quick wiring questions.. ( i suck at this shit haha) but.. i have an AZ compressor in my trunk for my setup... and i was told it is really good to use a solenoid i just wasnt sure what is involved in the setup... if i use a solenoid do i still need a fuse? and i was looking at some solenoids and a web site and i got a little confused.. the solenoids had the two main posts on them for the 12v source from the battery, but most of them also had other smaller posts... what are those for? grounds? any help would be much appreciated/needed.. thanks in advance...

yes you will still need a fuse. thats protection in case of a short so youre ride wont burn to the ground.

youll want a 100% duty solenoid. there are 2 big posts. 1 is 12V from battery, 1 goes to the compressor. there are 2 smaller posts. 1 is a ground, 1 goes to your pressure switch with 12V+.

also, with a single AZ, youll want to run like 8 gauge power wire with a 40-50 amp fuse.

Originally posted by 86IsuzuPup



yes you will still need a fuse. thats protection in case of a short so youre ride wont burn to the ground.

youll want a 100% duty solenoid. there are 2 big posts. 1 is 12V from battery, 1 goes to the compressor. there are 2 smaller posts. 1 is a ground, 1 goes to your pressure switch with 12V+.

also, with a single AZ, youll want to run like 8 gauge power wire with a 40-50 amp fuse.

dude... your the man!!! haha.. thanks for the help... yep.. im probably gona run like 6 gauge wire just to be safe and like a 60amp fuse? would that work ok? thanks again!

definitely go with one of the 100% duty solenoids.. cost a little more, but you'd be replacing relays/starter solenoids alot

I would say go with a 40 amp fuse.. you dont want to go alot higher than the amps that you do pull on it. Because it will take longer to pop the fuse if there is a problem.

kool guys.. thanks again for all the info... now im pritty sure the fuse should be pritty close to the battery is that right? would it be ok to have the solenoid in the trunk near the compressor?

ok. one last few questions... im about ready to finish my wiring.. i have a pressure switch/realy built in.... and i just bought a solenoid toay... . on the pressure switch it has a wire for 12v when key is one, a 12v under load (compressor) and a 12v fused....i just need to know if i can run the 12vload and 12v fused wire from the pressure switch to the little post on the solenooid.... thanks guys...

by running that pressure switch with the built in relay along with a solenoid, you are doubling up a little bit.

you WILL be safer running it through the solenoid since those AZ are a little power hungry, and the relay in the viar p/s are known for failing.

this is how i would do it.

run a 12V switched (ie ignition, toggle inside, whatever) to both the 12V "key on" and 12V "fused" of the pressure switch. run the 12V "under load" to a little post on the solenoid. ground the solenoid as well as the pressure switch(if there is a lead). connect a high current, fused wire to a large terminal of the solenoid, the compressor to the other side.

dont worry about having the high current side of the relay connected to a low current circuit, you are mearly using the realy to trip the solenoid at this point(which takes little current).

also, have your fuse less than 12" away from the battery. the solenoid can be anywhere.

awesome info man... that clears pritty much everything up for me.. thanks... now for the trigger wire and the 12v fused ... do you think 12 gague wire is ok for those? and dose it matter how large of wire i use for groud wire for the compressor itself? and im pritty sure i got a solenoid that doesnt ground itself by mounting.. so i should be ok to bolt it to a wooden platform as long as its grouned through the other small post correct? thanks agian man.. sorry for all the stupid questions...

id only use 18-16 gauge personally. it doesnt really matter tho. use a decent sized ground wire for the comp. especially if it has to be long. (12-10 gauge). and yes, mount the solenoid whereever as long as its grounded.