Trying to use a NOS solenoid for air shift, HHave cpl off small systems that are laying around and priced right,zero.

Problem is that about every 3 or 4th time it blows fuse. It on for about .5 seconds just enough for air to engage solenoid.

Question does this little solenoid need a relay? Have blown two 20 amp fuse and one 25,so doubt it should have more fuse is issue.

Only if it's blowing fuses. Oh wait............

With your meter set to ohms measure across the unconnected electric over air solenoid leads. Most Humphrey types will read 35 ohms. This is approximately 0.4 amps to activate

You do not need a relay to trigger this. Sounds like something is shorted out to me.

Was thinking short in solenoid,but had two do same thing. Whats the odds I pick two out of six that are bad.Better than my lottery picks.LMAO

Looking online I see that depending on the NOS type this can draw considerable amperage.

My suggestion is to use a Humphrey 310 electric over air solenoid. Ebay has them new for $25 delivered

Some of those solenoids are CURRENT HOGS! Especially those from Nitrous Express.

But that being said, NONE of them take more than 20 amps to operate.

Do you have good wire running to it? At least 14 gauge, 12 is better.

Do you have full battery (or alternator) voltage at the solenoid when it is powered? Low voltage will draw even more current.....

No need for a relay PROVIDED the switch that is turning that solenoid on and off can handle 20 amps or so.

And the fuel solenoids will take much less power to operate, BUT they may not like a lot of pressure against them.

I have had some take a little over 25 amps.

Now could be switching deal as Mike mentioned. Its actually activated thru delay box, Like stated using it to control air to the shifter.Also might be the on/off in .5 seconds thing.

After seeing the humphrey solenoids I figure I will just order 2(got to have spare) of those for 50 bucks and be done with it. The NOS piece was just temporary deal anyway. At least I know system itself is working. Maybe fuse will hold outy for on stand testing tomorrow and all systems functioning.

I know my voltage drops from 13.4 to 12.9 when the nitrous comes on with my junk. That's with a 100 amp alternator too.

As far as running larger wires, the wires coming out of my solenoids are only 18 ga. to start with. How will a larger wire help?

A DC solenoid is a purely a resistive load. By adding voltage, it will draw more current. Therefore by having too small of wire will produce a voltage drop that will REDUCE the current. Review Ohm's Law.

I (current)= E(volts)/R(resistance)

Regardless, I would be using the smallest solenoid that will do the task. Smallest being the highest resistance value.

Good luck
BW

wire from delay box is 12 or 14,wire built into solenoid is 30 something,well its dang small.I have to use samllest notch on strippers to strip the end.

2 new humphrey deals are on the way.

quote:

Originally posted by bry-war:
A DC solenoid is a purely a resistive load. By adding voltage, it will draw more current. Therefore by having too small of wire will produce a voltage drop that will REDUCE the current. Review Ohm's Law.

I (current)= E(volts)/R(resistance)

Regardless, I would be using the smallest solenoid that will do the task. Smallest being the highest resistance value.

Good luck
BW

You are correct.

That being said, get a purge solenoid, they pull very little power and can easily be fed by a 14 or 16 gauge wire.