nosmokingbandit

I'm putting fog lights on my Cherokee. They are two typical 55w halogen deals. On past vehicles I've wired the switch and relay with power from the fuse box and the lights get power from the battery. But its so damn cold outside right now I'm trying to work as much inside the vehicle as possible.

I've wired in my switch with power by jamming a blade connector into an acc powered terminal in the fuse box, and I'm wondering if it would be ok to use that same feed to power the lights themselves. Still triggered by the relay and with a fuse in-line, of course, but this way I don't need to splice something off of the battery or run wires from the battery both in and out of my firewall, I can just have the lead coming off the relay going to the lights.

Firehawk068

I would mount the relay as close to the front of the Jeep as I can..........
Power it with a fused wire directly from the battery.
Run the trigger wire from the switch up to the relay............Make sure you fuse the power wire to the switch also........

Puddlejumper97

Wait until spring and wire them then : D

Turbo X_J

or start smoking...

nosmokingbandit

Ok, three posts and no solid advice. Brilliant.

I can see why pulling that few amps (~9.2) through the panel would be any worse than running an extra 12 feet of wire in order to attach directly to the battery terminal. So I'm probably going to do that unless someone has anything helpful to add.

Turbo X_J

How about may be specifying what year this vehicle is? The fog light wiring may already be in place.
I've been at work all day (I was even outside for a while, I guess I'm a badazz) and my telepathy is fading.

ETA:
I guess you missed the smoking fuse box thing huh, eh?

Firehawk068

I thought my advice was pretty solid......................although, I am assuming you are mounting the lights up front (like on the bumper somewhere) since you did say you were putting fog lights on your Jeep.................(fog lights are typically mounted up front, underneath the bumper, as close to the road as possible to reduce glare)


If this is indeed the case, you will want to install the relay up front somewhere (usually somewhere close to the battery), that way, you only need to run (1) power wire through the firewall from your switch, to turn the relay on..............The wire that actually powers the lights just runs from the battery, to the relay, to the lights. (put a fuse on this wire, as close to the battery as you possibly can)


I was somewhat confused by your original post, as it seems you are set on mounting the relay (inside) your Jeep...............
If you were mounting the lights, say..............on the roof, or on the A-pillars, this might be appropriate....................However, you never mentioned where the lights would be mounted.......
So I gave you my most solid advice based on my assumption...............


For what it's worth, outside temperature should have little to do with wiring your Jeep properly...................Relays still function in below zero weather.

nosmokingbandit

I read what you posted, but I want to know why it is inappropriate to mount a relay inside. How without a why doesn't satiate my curiosity. Is the fuse panel inside unable to handle that kind of draw? The lights will be on my bumper, so I'm running 12ga from the power source to the relay, then from the relay to the lights themselves, which is more than adequate for that length of a run. So the bottleneck for conductivity would be the Jeep's factory harness, but I'm not familiar enough with the factory harness to know if it would be ok to pull an extra 10a through the dash.

My cherokee is a 94 sport, but even if factory wires are installed I don't want to use them because I already have problems with my factory headlights because of Jeep's terrible wiring. One of the engineers should have mentioned that 30 feet of 18ga can't quite handle headlights.

I'm not looking for a shortcut, I probably would have wired it up this way even it it were warm out, the weather is only keeping me from running the power feed through my firewall. By the time I get home from work it is typically pitch black and below freezing outside, so I only get time to work on fun stuff on weekends. I was really hoping someone might know some actual facts about the factory harness.

SteveMongr

By having a relay in the cab there is constant power direct from battery in the cab at all times. This is what you want to avoid, it is unsafe and not necessary.
The idea is to only have switched power inside the cab.

That ACC port can be used as a trigger but not to actually power the lights.

Firehawk068

^^^This........................And also, by running the extra amperage through an accessory tab on your fusebox, you are running all of that axtra current through the ignition switch (which as these XJs get older, is more prone to failure)

You already stated in your very first post, that on your past vehicles, you have ran the power dirctly from the battery to power the lights....
What was your reasoning to install it like this in the past?
Why would your reasoning change now that it's cold outside? (other than "It's cold outside, and I want to be inside")

The factory wiring in the XJ is "adequate" at best, for factory accessories........
When you start adding lights, and other accessories, relays are your friend.............takes very little current to operate them.
Run the higher current circuits directly from the battery, or a power-block mounted close to the battery.....