Wiring - 4 Extra Brake Lights - Parallel or Series???

So I have a Vetter trunk with 4x tail [BRAKE] lights (main reason I liked it).
Should I rewire the lights in series or parallel?
I haven't looked at them closely to see how PO or OEM wired them

 

join all the live & all the ground wires, so you just have one of each to go to the loom.

 

Wizard that part is a given...

Parallel = 1 wire splitting 4 times
Series = 1 wire going from each light to the next
I'll check the trunk in the AM if no one has a suggestion how it should be rewired.

 

the stock tail/brake light on my 550 that wired the 2 tail lights and the license plate light was wired in series.

 

It's almost certain to be parallel.

For it to be series the bulbs would have to be rated at less than 12 volts. For instance, if there are four of them they would be 3V lamps (12/4 = 3).

 

Wire them in parallel. a series wiring would make the lights to dim to see.

 

I would agree.... wiring in series causes the voltage to be divided among the items wired in. Wiring in parallel causes the amperage to be divided among the items wired in. The only issue might be pulling too many amps and burning fuses or melting wires in the harness, since they weren't designed to pull that much juice. You'll probably be ok, just something to keep in mind. I'm sure there are guys here with a lot more experience in adding on to the electrical system of an XJ than I, and I'm sure they'll let us know if I'm blowin' smoke....

 

I was considering tossing an inline fuse inside the trunk. I'm just not sure what size.

 

Change the bulbs to LED, no current issuse there. Changing to LED bulbs introduces other problems with the signal flasher.
Standard 1156 and 1157 bulbs are 26.6 watts, thats 2.2 amps per bulb, 8.8 amps total. I would use a 10 minimun fuse, 15 would be better. The added amperage will make your flasher relay flash fast. You will have to replace it with a electronic one.
My suggestion:
Change rear bulbs to LED, add electronic flasher

 

I might consider swapping out the BRAKE lights for LED when I get a few more spare $$, but buying 6 at once would be costly.
I'm assuming you meant no conversion needed for LED BRAKE lights.

Yeah LED signal lights might be in my future later.

Looking inside the trunk today. The wires are a total mess. I couldn't tell how they were wired, but I'll wired them in parallel when I do redo them. I probably should test all 4 before I get to carried away.

 

I dont think wireing in series has any effect on your voltage,unless every house owner would be complaining of a voltage drop over the run of his/her power outlets ( wired in series ) .Either will do the job of getting the current to the device. The most important part is to ensure that each lamp has a good earth.this can be done in series also,but you will have less problems if you give each lamp its own earth wire ,taken to a central earth point.

Cheers, Murray

 

House wiring (from the item plugged into the walls perspective) is parallel.
Draw it out.

In a series circuit if you removed one globe, all would then be out.

 

Well,yes , O.K but I interpreted the question as asking could he run a wire from lamp to lamp (ie in series,one after the other ) rather than run a seperate wire to each lamp , and as the wires are joined at a common +terminal in each lamp,removing the bulb has no effect on continuity.
( in strictly electrical terms parallel,yes,but as I said I didnt think this was what he wanted to know )

Cheers, Murray

 

Bob, what part of that was a given, you asked the question, I gave you the answer.

 

It was a splendid answer to! I have a bad feeling about 4 x 25w brake lights switching on at once! they will probably glow dimly as they will go through a poor earth (Ground).

Murray: You've confused me and I am an Electrician!!! BTW Are power circuits wired in radial or rings down under?

 

I added (3) 6-LED Red Strips for Brake Warning.

The LEDs Strobe 5-Times and come-on steadily ... EACH time the Brake Light comes-on.

The Kit is from "Signal Dynamics"http://signaldynamics.com/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=40&category_id=14&option=com_virtuemart&Itemid=77&vmcchk=1&Itemid=77

They also have a Module that will light your turn signals with the brake light AND still retain the signal light function.