Wiring up a Solenoid and compressor for on board air

[Paul2131]

Hi All,

I recently purchased a Boss Compressor, 100AMp Solenoid and Pressure switch of an Ebay Seller.

I connected it as per the wiring diagram sent with the compressor as per below

• I have heavy duty cable from the Battery Via an 100am fuse to the compressor.
• I have heavy duty cable from the negative side of compressor back to the big lug on the side of the Solenoid
• I have heavy duty cable from the other large lug on the side of the solenoid direct onto the negative side of the battery.
• I have heavy duty cable from the base of the solenoid direct onto the negative side of the battery.
• I have normal auto cable running from one side of the pressure switch direct to a 12v Supply (Direct to the battery)
• The other side of the pressure switch (normal auto cable) goes direct to the one of the small lugs on the side of the solenoid.
• I have a 12v supply through out all the wires including the negative side of compressor back to the big lug on the side of the Solenoid.
• I have 12v supply on both small lugs of the solenoid
• I have a 12v supply on both side of the pressure switch
• The only place I have no power is from the large lug on the side of the solenoid direct onto the negative side of the battery.
• If I remove the cable from the solenoid that is connect up to the negative on the compressor and connect it direct to the battery the compressor fires up.
• The solenoid you sent me reads “Baxters 11885 Continuous@

This set up did not work so I emailed them and they sent me this which is totally opposite...

Should be (as I have in my car)

* H/D Positive from battery through fuse to left post on relay
* H/D Positive from right post on relay to compressor
* H/D Negative from compressor to foot of Relay
* H/D Negative from foot of relay to battery/Ground/Chassis etc
* 3mm positive from battery to switch in cab/ignition with in line fuse
* 3mm positive from switch in cab/ignition to pressure switch
* 3mm positive from pressure switch to small post on Relay

That should be it, If you follow that to the letter it should work with no problems,
You will need to make sure that all are Positives and earths are independent and cannot
touch anything anywhere,..............

This set up did not work and once connect it shorts out my battery and I get a load of sparks coming off the negative terminal of the battery.

I have check that I have followed both intructions to the letter but cannot get it working.

Can anyone advise me how they have connected thiers up?

Thanks

Paul

[chimpboy]

The second description sounds correct to me.

This bit:

"* H/D Negative from compressor to foot of Relay
* H/D Negative from foot of relay to battery/Ground/Chassis etc "

... is effectively a continuous connection from the compressor to the chassis/ground, that stops by the relay on the way.... did you do this right?

The first description I had a bit of trouble following.

[-Scott-]

I waded through the original setup, and couldn't find a mention of a connection between the solenoid coil to ground. You have a wire on one of the small lugs, but what's on the other? If they both have 12V on them then the coil isn't energised, so the solenoid won't pull in.

Try connecting ground to the other small lug.

[chimpboy]

I waded through the original setup, and couldn't find a mention of a connection between the solenoid coil to ground. You have a wire on one of the small lugs, but what's on the other? If they both have 12V on them then the coil isn't energised, so the solenoid won't pull in.

Try connecting ground to the other small lug.

I was wondering if this was a one-terminal coil on the solenoid, since the description talks about the "foot" of the solenoid? ie it needs a grounded body?

Dunno.

[Paul2131]

Thanks all for your help and thanks to Dan from Danbri Canvas but I now have it up an running....I was missing the earth from the 2nd small prong on the relay back to the battery so the relay was not switching...connected that and flicked the switch and she fired up.....Thanks again guys

[-Scott-]

I waded through the original setup, and couldn't find a mention of a connection between the solenoid coil to ground. You have a wire on one of the small lugs, but what's on the other? If they both have 12V on them then the coil isn't energised, so the solenoid won't pull in.

Try connecting ground to the other small lug.

I was wondering if this was a one-terminal coil on the solenoid, since the description talks about the "foot" of the solenoid? ie it needs a grounded body?

Dunno.

That was a possibility, but I couldn't figure out what the other small lug would be.

All fixed now - that's the important thing.