Rednroll

So you really think that Chrysler would design a light circuit that doesn't have protection against that? Even without adding additional lights the potential for a back feed is possible.

What do you know about OEM testing specs of electronics? I'll tell you because, I work in the design of OEM electronic parts. Chrysler has testing specs that all electronic circuits must pass which includes a back current feedback test, a reversed polarity test, an ESD (Electro Static Discharge) test and even a short to ground test. So the things JK-Ford is recommending to add...such as a Diode...to prevent such a thing is already built into that circuit or it would have never have passed any of those tests. On top of that....how much back feed are a couple of extra 55 Watt light bulbs going to cause? This is not an ignition coil inductor which creates a large magnetic field....it's a light bulb.

If you want to go further with that back feed scenario, JK-Ford also recommended using a Relay connected to that same circuit we're talking about. What is a relay? A relay has a coil of wire in it, which creates a magnetic field which in-turn then pulls a metal strip to close a switch. The coil in the relay is a source of back feed, therefore adding the relay actually increases the amount of back feed that could go to that circuit.

tomharley

I think there is a misunderstanding between us. (Maybe my English)

I fully agree with you, and I think the same thing. Check my previous posts and see that I wrote that the diode, or an extra wire is not necessary. I have an extra reverse light connected simply and directly into the circuit

JK-Ford

Just because it works doesn't make it right. It's your Jeep. And it's your risk.

I have considerd this. So, just how much can you add to this circuit? This is actualy a good reason not to add additional lights to this circuit. Unless, maybe you never intend on towing!

Once again, "Reckless"! Adding devices till the fuse blows is "electrical insanity"! Adding devices with a propper understanding of the circuit characteristics is the ONLY intelligent way of doing this.

If industries add backfeed protection to every circuit installed, circuit design would be to cumbersome and to expensive to produce, maintain and market So I call this one "BS".

Ya lets! - If you are as good as you say, then surley you located the device intended to prevent backfeed on the "tapped" OEM circuit in my drawing. If you can't understand these drawings, then let me know and I will highlite the device for you!

Guy's, It's your Jeep. And I'm not asking anyone to take my word for gospel! Do your own research. Draw your own conclusions. Take what ever level of risk that you deam acceptable. But I can tell you as a 30 year vetran of the electrical industry, I'll not wire my Jeep that way.

ShakyJake

Do what you wish, and try to justify it. JK-Ford is correct, you may be taking a risk easily averted with proper wiring. Backfeeding is an issue. Also, consider how many amps total that reverse circuit is drawing, and look at the gauge wire carrying it and factor in conservative variables. If it falls into specs, go for it. If it pushes the limits, you're taking chances. You can plug 12 cords with an adapter into a duplex outlet and it could work fine for years, but one day it could burn your house down.
Honestly, for less than $10 , you could do this mod. properly.

tomharley

Yes, consent! But so it is with every modification. Lift, big tire, wheel spacers, bumpers and many more, for ex. That it works, does not mean it's right.

JK-Ford

So did you screw up other stuff on your jeep too? Your comparing apples to oranges now. Electrical instalations can be done right. I do it every day. Besides, I'm sure that there are a lot of guys on this form that put a lot of effort into making sure that their modifications are done right!

MikekiM

I am interested in adding lights.. Posted in the linked post but didn't get a response about sizing the diode? Are there different sizes and if so, how do you determine what size diode to use?

JK-Ford

Diodes are rated like fuses. The correct size diode for the relays are tinny. So just pick one that is large enough to work with.

MikekiM

Large enough to work with... as in it's physical size??

Can the diode be too large for the application as a fuse could?

JK-Ford

Yes, physical size. Your relay only draws 1/10 amp. A diode close to this rating will be so small ( physically ) that it will be hard to hold. A larger diode will be overkill ( electricaly ). But you will not need a magnifying glass to work with it. In this case, a larger rating diode will stop more current.