Time delay for air pump

[bkaiser]

I got tired of my air horn compressor kicking in whenever the truck was turned on. I want all of the amps going to the heater grid, not running the compressor.



I bought a time delay relay that keeps the air compressor pressure switch out of the circuit for one minute. By that time the truck's running and making lots of new amps.



If anyone is interested, I'll be happy to share part numbers, sources and the easy schematic (three wires).

 

[Butch Brandt]

I'd sure be interested. Right now I've got a manual switch before the pressure switch for that very reason. Of course, here we only use the grid heaters a dozen times a year, but when you forget--you've got no horn.

 

[bkaiser]

The device I used is made by a company called Amperite. It is their p/n 12DNO. 1-60C. To decode: 12V, DC, Normally Open contacts, 1 to 60 second delay, solder terminals. This little box, about 1 x 1 x 1 1/2 inches has four terminals and one knob. The knob adjusts the delay.



The four terminals are:

1) Timer input.

2) Timer ground.

3) Feed to load.

4) Supply for load.



I wired pins 1 and 4 together. I then removed the feed to the air compressor pressure switch feed (3 amp fused) and used that line to feed pins 1 and 4. I ran a wire from pin 3 back to the air compressor pressure switch. I grounded pin 2 to my compressor mount.



Now when I turn on the truck, the timer circuit receives power, but the switch contact is open until the timer closes the contact. Once closed, the contact remains closed until power is removed (the truck is shut off).



The device is rated for service from -13 to +140*F, but isn't claimed to be waterproof. I did apply some RTV to the terminations when I was satisfied everything was how I wanted it.



This device should be available from any good industrial supply house. I bought mine through Allied Electronics for under $30. Details are availabe at www.amperite.com/cseries.htm and www.alliedelec.com.

 

[Doubleclutch]

Casting no aspersions here... How fast does your tank bleed down? I removed my truck's compressor, installed a little larger tank and just "snooped" all the airlines. You guys don't honk at every crossing do you???

Greg

 

[HoleshotHolset]

"You guys don't honk at every crossing do you???"

Sometimes I think we should... .



But we should use ocean liner or real train horns. :-laf



Gotta make the old folks test their Depends... .



Matt

 

[bkaiser]

I should get out the bottle of 'Snoop' and check my lines, it bleeds down overnight and I know it shouldn't. My real motivation in adding the delay was for unassisted cold starts - backwoods winter camping is not the time to have a no-start!

 

[bighammer]

I will be interested as I just bought air horns and compressor CHEAP on eBay. Oo. Oo. Woo Hoo

 

[bighammer]

(more memory, Steve. I've gone smiley OVERLOAD )