Electrical: Backup lights power source

[Craig]

Looking for a safe adequate power source for back up lights on a 55 Commander.
The factory wiring for these back up lights ties into the tail light power wire on the firewall.
I would like these lights to activate at all times the ignition is on and shifted in reverse for daytime alert as well.

Looking at wiring diagram for an "ignition on" terminal and close by to the backup light switch is overdrive relay.
Is this a safe place to power back up light switch?

[Big Dan]

You might want to check your state laws about "showing a white light to the rear" I know it's illegal in many states when not backing or in reverse.

[Craig]

Thanks, I should have said back up light switch mounted on column. So only when shifted into reverse.
I might need a fuse as well.

[Big Dan]

I misread your original post - da doy!

[Craig]

Dan, I did edit the original post to make it clearer. Now you read it and it makes more sense.

[Hugh]

My 51 Commander is wired from the circuit breaker on the headlight switch under the dash, but this is not easy to get to, soooo why not an in-line fuse attached at the batt cable on the starter solenoid? Short run to switch and hot all the time, but still the b-u lights only come on when I’m reverse.
Hugh

[rockne10]

I believe Craig understands these were originally wired to only come on IF the headlights or parking lights were on, and is asking how to source power to the backup switch so they will come on anytime reverse is engaged.

Craig, yes; the overdrive relay wire is constantly powered when the ignition is on, and can be used to power your backup switch.

[r1lark]

My 51 Commander is wired from the circuit breaker on the headlight switch under the dash, but this is not easy to get to, soooo why not an in-line fuse attached at the batt cable on the starter solenoid? Short run to switch and hot all the time, but still the b-u lights only come on when I’m reverse.
Hugh

If I understand what you are saying, the b/u light switch will have power all the time, even if the ignition switch is off.......is this correct? If so, putting the car in reverse when parking (which is a good practice with an overdrive-equipped car or when parking on a hill) will cause the backup lights to be on when parked. At least, that is what it seems like to me.

[enjenjo]

If your car is equipped with a cigar lighter you can use that as the power source as long as the lighter is not powered with the ignition off.

[Craig]

Cigar lighter is wired hot all the time, direct off ammeter.

[enjenjo]

I wasn't sure if it was or not.

[Son O Lark]

Accessory source so it is not lit when parked in reverse.

[Hugh]

Craig, my sincere apologies for even suggesting a connection that would power the b-u light switch all the time, obviously not the best scenario. If you connect to the accessory terminal on your ign switch then you will have circuit breaker protection as well as live power only when ign switch allows it. THATS why we have this forum, to monitor AND hopefully not getting bad info. Again I apologize to all. Hugh

[RadioRoy]

If you connect to the accessory terminal on your ign switch then you will have circuit breaker protection as well as live power only when ign switch allows it.

That's what I would do.

[Corbinstein0]

you have backup lights? I back up till it sounds expensive!

[Craig]

there are 4 wires on the ignition switch -
1 power from ammeter D
2 power to starter solenoid T
3 power to coil J
4 power to OD relay Q, window wiper motor, temp gage & gas gage. F
none of these circuits/terminals/wires are protected by a fuse or breaker.

But I get the point - find a breaker or fuse to connect to thru the firewall and under the dash.

It simply seemed more efficient to add an "ignition only hot" fused wire to the firewall mounted OD relay sitting right above the BU switch.

The only other "ignition only hot" terminal on the firewall is the ignition coil. This would require adding a fused wire.



the original tie in point for BU switch was on the firewall at the tail light 2 wire connector (not shown here) and when the tail lights were powered the BU lights could be powered ......with a breaker protecting the lights.