Looking for a 12V Ignition Source in Battery Compartment

corvettec3 · 03-30-2012, 08:30 AM

I am hooking up the compressor for my Air Lift system and the power source needs to be connected to a source when the ignition key is on. Rather than running a wire all the way up to the front is there an ignition source somewhere in the battery compartment? I am thinking there must be in order to enable/disable the charging circuit when the engine is running/not running. Before I start probing around with my tester, I thought someone may know which terminal to tap in to. Coach is a '99 Chieftain with two coach batteries and one chassis.

John Hilley · 03-30-2012, 09:31 AM

The coil terminal on the battery isolation solenoid. I would only use it to power a relay though, not the pump itself.

FIRE UP · 03-30-2012, 10:50 AM

Quote:

Originally Posted by corvettec3

I am hooking up the compressor for my Air Lift system and the power source needs to be connected to a source when the ignition key is on. Rather than running a wire all the way up to the front is there an ignition source somewhere in the battery compartment? I am thinking there must be in order to enable/disable the charging circuit when the engine is running/not running. Before I start probing around with my tester, I thought someone may know which terminal to tap in to. Coach is a '99 Chieftain with two coach batteries and one chassis.

corvettec3,
Typically, there's no "ignition hot" points in a Class A battery compartment. But, in the RV world, there always seems to be exceptions. But, as stated above, the solenoid that controls battery voltage going to the house batts and chassis batts is one source. What kind of "lift" system are you powering up" if I may ask? Also as stated above, depending on the load you're planning on establishing with this ignition hot source, it might be better to establish an entire new route, through a relay, large or small, to your lift system.
Scott

John Hilley · 03-30-2012, 12:10 PM

Another source is the ignition step over ride on the step controller, again only use it to control a relay which switches the battery to the compressor.

wa8yxm · 03-30-2012, 01:06 PM

A lot depends on your battery control system.. For example, on my coach there are 3 "Chassis" fuse blocks, and yes, there are spear taps for "Ignition" circuits. (and accessory) but that's where you are most likely to find one, a spare tap on one of the fuse blocks.

corvettec3 · 03-30-2012, 01:11 PM

Quote:

Originally Posted by FIRE UP

corvettec3,
Typically, there's no "ignition hot" points in a Class A battery compartment. But, in the RV world, there always seems to be exceptions. But, as stated above, the solenoid that controls battery voltage going to the house batts and chassis batts is one source. What kind of "lift" system are you powering up" if I may ask? Also as stated above, depending on the load you're planning on establishing with this ignition hot source, it might be better to establish an entire new route, through a relay, large or small, to your lift system.
Scott

Thanks Scott and John. The compressor has an inline 15 amp fuse. The lift system is the air bag system from Air Lift. I have a rather steep driveway and I needed a few extra inches of clearance to back up the grade without scraping. It may be easier for me to run the wire right up to the main fuse box and connect there rather than install a relay.

corvettec3 · 03-30-2012, 03:28 PM

I was looking at the wiring diagram for the compressor setup and noticed that it is already using a relay. The setup is being installed in the compartment a couple of feet away from my battery compartments. Reviewing this diagram why can't I connect the 10 gauge pink (with fuse) to one of the large 12V + terminals on one of the solenoids and the 18 gauge pink (bottom terminal on relay) to the coil terminal on the battery isolation solenoid? Will that work for me?

John Hilley · 03-30-2012, 09:02 PM

Yes, that should work fine. Just test the connection first with a test light or volt meter. If the 12 vdc comes on with the ignition turned on, it will work.

corvettec3 · 03-31-2012, 05:18 AM

Quote:

Originally Posted by John Hilley

Yes, that should work fine. Just test the connection first with a test light or volt meter. If the 12 vdc comes on with the ignition turned on, it will work.

Thanks John, will give it a try :-)