Adding Secondary Override Switch for Reverse Lights

[tjonesdfw]

In the process of installing the Black Dog Customs reverse light harness activated by a switch added to the shifter assembly to power some round ambulance style reverse lights, but would also like to be able to manually activate the reverse lights via switch. I've seen a diagram somewhere online where someone did this with a 24v switch, and have a dedicated 24v switch in the New Wire Marine panel I had made. Would anyone happen to know a simple way to do that?

 

[canadacountry]

I may be overlooking something but I wonder why it couldn't simply be wired in parallel considering its the same battery and load at both ends but just two different mechanical actuations in the middle nevertheless? (that is if you put transmission in reverse and had the aux switch on at same time then so what? it'll still lit up that is?)

 

[Mogman]

Simply wire 24V through the switch to the lights, could not be easier
Did you say you made that panel? if so nice work!!!

 

[Mogman]

The only caveat is that if you put the trans in reverse while you have the lights in by-pass and the run switch off it will try to back feed the run circuit.

This would seem to be a very rare occurrence as you are not likely to put the trans in reverse without the truck running.

There are two ways I can think of to mitigate this issue, one use a small (3A or so) auto reset breaker on the by-pass circuit, (or use a manual breaker as the switch in the panel) in the event you did put the trans in reverse with the run switch off the breaker would simply open.

The other would be to use a DPDT switch and run the shifter reverse circuit through one side of the switch to open that circuit when in by-pass mode.


You should do one of these two methods because if not and the trans was to be shifted into reverse when the the run switch is off and the backup lights in by-pass it would likely overload the switch in the shifter, the switch in the panel and or the wiring.

 

[tjonesdfw]

The only caveat is that if you put the trans in reverse while you have the lights in by-pass and the run switch off it will try to back feed the run circuit.

This would seem to be a very rare occurrence as you are not likely to put the trans in reverse without the truck running.

There are two ways I can see to mitigate this issue, one use a small (3A or so) auto reset breaker on the by-pass circuit, (or use a manual breaker as the switch in the panel) in the event you did put the trans in reverse with the run switch off the breaker would simply open.

The other would be to use a DPDT switch and run the shifter reverse circuit through one side of the switch to open that circuit when in by-pass mode.


You should do one of these two methods because if not and the trans was to be shifted into reverse when the the run switch is off and the backup lights in by-pass it would likely overload the switch in the shifter, the switch in the panel and or the wiring.

I was wondering if I was overthinking it, but seeing your line of thought makes me think I wasn't.

The only caveat is that if you put the trans in reverse while you have the lights in by-pass and the run switch off it will try to back feed the run circuit.

This would seem to be a very rare occurrence as you are not likely to put the trans in reverse without the truck running.

There are two ways I can think of to mitigate this issue, one use a small (3A or so) auto reset breaker on the by-pass circuit, (or use a manual breaker as the switch in the panel) in the event you did put the trans in reverse with the run switch off the breaker would simply open.

The other would be to use a DPDT switch and run the shifter reverse circuit through one side of the switch to open that circuit when in by-pass mode.


You should do one of these two methods because if not and the trans was to be shifted into reverse when the the run switch is off and the backup lights in by-pass it would likely overload the switch in the shifter, the switch in the panel and or the wiring.

I wondered about back feeding and the last thing I want to do is cook any wiring in this panel. The only purpose of the switch though would be to activate the reverse lamps manually every now and then if the truck is on and not in reverse. Otherwise, the reverse lamps will only activate when the shifter is placed in reverse. The indicator lamp above the switch comes on when the switch is closed, so you would know the override is active before putting the truck in reverse.

 

[tjonesdfw]

Simply wire 24V through the switch to the lights, could not be easier
Did you say you made that panel? if so nice work!!!

I designed and spec'd the panel but had New Wire Marine build it because of all the etching. The etched lettering is all backlit in green fiber optic, and the green LED indicators above each switch light when each switch is closed. Also added a blackout 12v voltage gauge to the left to monitor my converter. Very impressed with their work and excited to get it all wired up.

 

[Mogman]

Actually this can be simply done with a SPDT switch, just cut the wire on the light side of the shifter switch and bring both sides to the switch.
Or break the reverse light wire anywhere along its path, same thing.
This will prevent back feeding the run circuit.

 

[Mogman]

I designed and spec'd the panel but had New Wire Marine build it because of all the etching. The etched lettering is all backlit in green fiber optic, and the green LED indicators above each switch light when each switch is closed. Also added a blackout 12v voltage gauge to the left to monitor my converter. Very impressed with their work and excited to get it all wired up.

That is awesome, what did that panel cost?
My main problem with custom stuff like that is I am always wandering around with ideas so it would be difficult to settle on a design.

 

[tjonesdfw]

That is awesome, what did that panel cost?
My main problem with custom stuff like that is I am always wandering around with ideas so it would be difficult to settle on a design.

It was around $400 with all the switches and wiring. I lost my marbles and went overkill on wiring and switching. Most of the circuits run back to an S-Tech Switch Systems relay panel under the passenger seat.

 

[tjonesdfw]

Actually this can be simply done with a SPDT switch, just cut the wire on the light side of the shifter switch and bring both sides to the switch.
Or break the reverse light wire anywhere along its path, same thing.
This will prevent back feeding the run circuit.
View attachment 931597

I didn't think about using a SPDT with the load on the center terminal instead. I guess I would either lose the LED indicator above the switch, or it would illuminate whenever the truck goes into reverse AND when the override switch was thrown when wiring a SPDT that way? Right now, the indicators are wired with piggyback blade connections to the load side of each switch.

 

[Mogman]

I didn't think about using a SPDT with the load on the center terminal instead. I guess I would either lose the LED indicator above the switch, or it would illuminate whenever the truck goes into reverse AND when the override switch was thrown when wiring a SPDT that way? Right now, the indicators are wired with piggyback blade connections to the load side of each switch.

I can fix that, be back in a minute

 

[Mogman]

Use a DPDT switch

 

[Mogman]

Curious was the panel specified for 24V?

 

[tjonesdfw]

Curious was the panel specified for 24V?

Just the reverse override switch and corresponding LED indicator are 24V. Everything else is powered through an Orion converter and run at 12V. They can build all 24V panels though.

 

[tjonesdfw]

Use a DPDT switch
View attachment 931611

Assuming you could just jumper between both 24V terminals in that setup? That would get the exact function I was looking for back on board. Thanks for all the help!

 

[Mogman]

Assuming you could just jumper between both 24V terminals in that setup? That would get the exact function I was looking for back on board. Thanks for all the help!

Yes you should use the same 24V feed for both functions, switched (run) or unswitched, of course it should be fused

 

[tjonesdfw]

Yes you should use the same 24V feed for both functions, switched (run) or unswitched, of course it should be fused

Any idea what the amp rating on those ambulance lights would be for fusing? They run incandescent bulbs now, but looking for a compatible LED.

 

[Mogman]

The fuse is to protect the wiring, switch etc. I would think 10A would be fine.