Portable 12V DC Air Compressor

[gonzo]

What's the best approach for hooking up a 12V DC Air Compressor to the Healey's 12V positive ground system? This small 100PSI unit, purchased from Harbor Freight, is designed to plug into a DC power outlet (e.g cigarette lighter) and works nicely on modern car electrics but it doesn't when hooked directly to the Healey's group 27 battery with engine on or off.

It might have something to do with the compressor's minimum amperage requirements, but seeking advice from group. Thanks, Gonzo

 

[Gliderman8]

Just a WAG.... Check the plug end to see if there is a fuse. If you find one check for continuity.

 

[Bob_Spidell]

A battery with enough amperage to crank a Healey engine over shouldn't have a problem driving a little compressor (I've got one in my BJ8). Agree it could be the fuse, but have to ask--sincerely--how you're connecting to the battery?

 

[gonzo]

Thanks for the feedback.

Connection to battery is through DC power outlet extension with alligator clips: Pos lead to Pos post and Neg lead to Neg post. Compressor is 15 amp fused and DC outlet is not fused. Fuse has not "blown"...yet For continuity question, set up works well with modern car electrics with ignition accessory "ON" and/or engine running.

Something else to note: When connected isolated fully charged battery, the pump does not work. Also, AH 3000 BJ7 is original POS ground, generator equipped.

 

[Keoke]

Use alligator clips sans the "DC Power outlet" Gadget and connect the pump directly to the battery, make sure the case is plastic or is physically isolated from the car body>>>>>?

 

[Gliderman8]

Did you check (with VOM) to confirm that the DC outlet in your Healey is delivering 12v?

 

[gonzo]

Success! Bypassed 12V leads and hot wired direct to battery. Either polarity works but will install in line fuse and isolate pump from car as suggested. Thanks all. Gonzo.