Ignition Wiring Sources

When y'all tap into a 12v ignition source for things like tachs and radios, how do you do it?

I believe I found my slow battery drain because my tach was tapped into a battery source.

My radio is currently tied into my heater switch, but that is a fused source feeding the fused radio power.

My electric choke took the only free 12v ignition source on the key switch.

I also need an ignition source for my new voltage meter.

Do you just tap a wire? Or is there a distribution block that would work for this?

Thanks.

 

There are several connection points on the back of the key switch you could use. You can also tie it to the run side of the starter solenoid. Regardless, fuse it.

 

Fuse meters such as voltage meters and tachs? If so, what amp?

 

Fuses protect the wire, not the device.

You can always use a relay to power a bus (or buss if you prefer) strip when the key is on, hook your various switchable loads to it.

Current draw of a device will dictate wire size, and fuse size.

 

Buss bar. That's what I was trying to think of to search. I found and will use this

http://www.amazon.com/gp/aw/d/B001BXKLNQ

Thanks.

 

I'm planning to run a wire from an accessory terminal on the key switch to the fuse block I plan to mount under the dash on the firewall. I plan to power my voltage meter, radio, small amplifier (30 amp input), and cigar lighter off the fuse block. Sound okay? Will a 10 ga wire from the key switch to the fuse block handle those items?

 

id power the amp off the batt the radio will switch it on and off via the blue power antenna wire. 10ga should be fine for the rest

 

Like said above but fuse the tac and voltmeter to the ign side of the switch and a 10 amp fuse will do. Wire the lighter to the acc side of the switch with it's own wire (10 ga) and not knowing what you are going to use it for, I can't advise as to size fuse. The lighter circuit should work with the key in the on or acc position so you can plug in an emergency light etc. without having the ignition on and burning up the points etc.

 

Thanks for the responses. What would it hurt having the voltmeter and tach wired to the accessory side? I'm currently wiring a fuse block to run these things along with the radio and the lighter. The amp I will tie to the battery.

 

Won't hurt wiring to acc side. Will have a slight unnecessary draw from the system though as the tac only reads when engine running.

 

Ok. As seldom as I would use acc only, the tach wouldn't draw much over the period.