Roof Rack Wiring? Search search I know...

[urbexx]

Ahhh that's exactly what I had in mind! So those are called well nuts? Nice speaker wire btw

Yep. The actual/technical term for them are well nuts, but they're more commonly referred to as rubber expanding nut. Big thing to keep in mind with those is just not to over tighten them. Snug them up just to the point of sealing, and that's it. Get a couple extra as you're likely to over tighten the first couple and pull the nut through the rubber. Oh yeah, I forgot to use washers underneath the terminals on the top, and that's why they're bowing like that in the pictures. Use washers, or ring terminals that cover the entire top, and they won't bow Other than that, they work great.

As for the wire - I often use speaker wire for these types of hookups. More flexible/easier to route, and it's incredibly convienent to have the positive and negative lines bonded together like that I even have some of that flat style home theather cable run in certain areas due to space constraits

 

[DanMan2k06]

Yea I use it all the time too. There's a local shop that sells an oil resistant version, that's what I use a lot. And it comes in much cooler colors than plain black - even better. arty:

 

[MaxxXJ]

dead thread, but everyone says to search, i've found this thread, i want to do a roof mounted rack but does anyone have any kind of better option ? i liked the coming out of the rear hatch idea, i also liked the speaker wire idea, i was thinking about going down the front windshield rubber seal inside that crack kind of concealed but im not too sure yet i want to do this sort of rack cuz my roof rack dont fully extend past the front doors. anyone have any better ideas?

 

[MaxxXJ]

dead thread, but everyone says to search, i've found this thread, i want to do a roof mounted rack but does anyone have any kind of better option ? i liked the coming out of the rear hatch idea, i also liked the speaker wire idea, i was thinking about going down the front windshield rubber seal inside that crack kind of concealed but im not too sure yet i want to do this sort of rack cuz my roof rack dont fully extend past the front doors. anyone have any better ideas?

 

[urbexx]

I will always support reviving a dead thread...I know it sucks, as it seems you're damned if you do, and you're damned if you don't since people will bitch if you revive a dead thread while searching, and other people will bitch if you start a new topic when "it's been covered a million times already", yet it doesn't really cover your particular situation.

Anyways, another possibility, although it takes a good deal more effort to make it work right, is to use the factory well nuts holding down the factory roof rack rails. The screws are not at all easy to get to on the bottom, and you have to make sure your terminals aren't touching the rails on the top side. But it does result in the wires being quite a bit more hidden, and you're not drilling any new holes in the roof.

 

[MaxxXJ]

I will always support reviving a dead thread...I know it sucks, as it seems you're damned if you do, and you're damned if you don't since people will bitch if you revive a dead thread while searching, and other people will bitch if you start a new topic when "it's been covered a million times already", yet it doesn't really cover your particular situation.

Anyways, another possibility, although it takes a good deal more effort to make it work right, is to use the factory well nuts holding down the factory roof rack rails. The screws are not at all easy to get to on the bottom, and you have to make sure your terminals aren't touching the rails on the top side. But it does result in the wires being quite a bit more hidden, and you're not drilling any new holes in the roof.

my only issue in drilling thru the roof doing well nuts is the fact if it's not done right your whole jeep becomes a positive terminal lol

 

[5-90]

There's also the fact that well nuts can wear out due to vibration - unless you're careful to dress the cut edge of the drilled hole (and even then - it just takes much longer.)

Going through the roof for me would be done using either CPCs (Circular Plastic Connectors) or actual, metal, honest-to-Gawd Amphenol units (which cost about three times as much, but are fully MIL-spec and are damned near impregnable.) Electrical is not something you want to cheap out on.

Both CPCs and Amphenols are availble with bulkhead connectors that actually screw to the bulkhead and are gasketed, and can have covers attached (if you remove the roof rack, you screw on the cover and close up the connector against weather that way.)

CPCs and Amphenols are available to take up to around a 10AWG wire in any of several circuits - in the Allied Electronics catalogue, they seem to have their own small section. Let's break down some requirements:

I'd wire the lamps in pairs - one pair for the reverse lamps (are you going to slave them to the OEM, or run them off their own switch?) and three pair for up front (so you can provide yourself with varying degrees of additional light. I'd also think about a sun visor or an undershield for those lights, unless you can move the roof rack far enough forward to have them clear of the "eyebrow" over the windscreen. But, I'm just funny that way.)

Rear pair - 2x55W = 100W. 100W/12V = 8-1/3A. Use a 10A fuse and circuit; as I recall, 14AWG should serve.

Front pairs - 3 @ 2x100W = 200W. 200W/12V = 16-2/3A. Use a 20A fuse and circuit - you'll want a quality 12AWG here (if they're up front. If they were going in the back, I'd suggest 10AWG to account for the extra conductor length.)

Yah, you're going to want all of these on relays. This will allow significant flexibility in switch selection, since relays only want 100-150mA to trigger (0.1-0.15A, which is loads less.) It also allows you to run more direct power leads, and you can use 18/2 SJOOW (rubber-jacketed, grease- oil- and water-resistant two-conductor cable) for your switch runs. Get that stuff at the local hardware store. You can use 14/3, 12/3, or 10/3 SJOOW for the main power leads to the lamp pairs, and feed the relays with a distro block fed with something like 6AWG or 4AWG (hit me backchannel, I can help you with some of this stuff.)

NB: Distro posts tend to be fairly tall - we're talking 2-1/2" to 3" here. You'll need to make sure you have enough "headspace" overtop of them, and putting a "screw protector" (plastic/rubber/elastomer cap" over the unused bit of the post isn't a bad idea.)

Given the choices, the current levels, and the environmental requirements, I honestly think that CPCs or Amphenols are the best way to go on these.

 

[MaxxXJ]

all of this work i'd have to do and now im half way discouraged to do lights up top now lol, i got 4 kc slimlites on the bumper and they light up a good deal, their all driving lights i am thinking if i do long range in the middle i'll get more lighting or invest in converting them to HID somehow. i want to do a roof rack but fact is, i got a 5x8 trailer, what dont fit in the xj can get pulled by the trailer, and when i go wheel the stuff stays at camp.

 

[urbexx]

my only issue in drilling thru the roof doing well nuts is the fact if it's not done right your whole jeep becomes a positive terminal lol

There's also the fact that well nuts can wear out due to vibration - unless you're careful to dress the cut edge of the drilled hole (and even then - it just takes much longer.)

I'm sure not about to argue with you, 5-90, you're obviously a wealth of knowledge, and know what you're talking about, plus I've even been helped by a few of your posts But....(heh..there's always a but, isn't there? )I've put years of hard use on my setups, including in stage rally cars, and haven't had a failure yet. I do go to lengths to make sure the drilled holes are dressed properly, but then I do that for all holes, even ones I'm just putting grommets into. This is also why I suggested using the factory rack nuts. If one or two does wear out, it's a couple bucks at the local hardware store to replace. Also, that possibility is why _all_ my circuits are fused. If one of those nuts wears through, it's no different than any other wire that chafes through, and shorts out against the chassis. If properly protected, such as with a fuse, it's a minor inconvienence.

All that said, I can certainly understand why some people would have aversions to utilizing it, and I don't take it personally

 

[StanBo]

I'm looking to use this when I do mine. This would allow you to remove the lights/rack if you wanted/needed to.

http://www.defender.com/product.jsp?path=-1|328|49758|112306|316479&id=680929

Have you installed this connector Mike?

 

[kastein]

I like the connector xj_mike linked. If I didn't feel like using one of those, I would probably use a waterproof multiposition through-panel barrier strip with a liberal amount of silicone/RTV dumped under it before installation.

What I used to do a similar project, mounting my dual air horn, was a custom cut gasket made from 1/8" nitrile/buna N rubber - worked great, I torqued some #10 bolts down a bit and it hasn't leaked yet, in a full year of installation time. You can get sheets of nitrile/buna N from smallparts.com for a very reasonable cost, I believe I paid 12 bucks for my 1'x1' sheet of 1/8".

I'd stay away from the insulated bolts trick... for some reason that really seems like it'll short out eventually as vibration turns the edge of the roof metal into a buzzsaw.

EDIT: the connector mike linked has a rated current per circuit of 16 amps with 4 circuits + 1 (not sure why they listed it this way, so I'll ignore that pole), and you can use the roof panel as your ground via clamping the rain gutters or the OEM rack bolt holes - this should give you the ability to run up to 880 watts worth of lamps, which will be using about 75% of your stock alternator's output capability so I think it's probably going to handle anything any sane person will try.

 

[StanBo]

Good info. I was considering converting at least 2 of my rooflights to HID. They will only be used on trailrides so glare isn't an issue.

I know the startup draw can be high on them but once they are running they will draw (or should I haven't done the full research) less then a halogen light. Plus I could turn on one set at a time to save draw load.

 

[5-90]

I'm sure not about to argue with you, 5-90, you're obviously a wealth of knowledge, and know what you're talking about, plus I've even been helped by a few of your posts But....(heh..there's always a but, isn't there? )I've put years of hard use on my setups, including in stage rally cars, and haven't had a failure yet. I do go to lengths to make sure the drilled holes are dressed properly, but then I do that for all holes, even ones I'm just putting grommets into. This is also why I suggested using the factory rack nuts. If one or two does wear out, it's a couple bucks at the local hardware store to replace. Also, that possibility is why _all_ my circuits are fused. If one of those nuts wears through, it's no different than any other wire that chafes through, and shorts out against the chassis. If properly protected, such as with a fuse, it's a minor inconvienence.

All that said, I can certainly understand why some people would have aversions to utilizing it, and I don't take it personally

No worries, mate. If it works for you, I see no reason for you to stop doing it!

Well nuts probably hold up for you so well because you're not putting any real mechanical strain on them. When I had to find (yet more!) roof leaks in my 88 (besides the sunroof I still need to get rid of,) it turned out that just about all of the well nuts holding in the OEM roof rack were failing mechanically, and that was in punched and rounded holes (not drilled.)

Oops.

Granted, there was a lot more mechanical stress involved there - particularly for me, since I was always tying something-or-other down.

I'll use them for mounting parts and suchlike - they work wonders there, and serve quite well when installed and loaded properly. However, just be aware of the small fact that they do have their limitations, and design accordingly. CPCs or Amphenols to go through bulkheads for me, thanks. They may cost more, but it removes a large number of worries.

 

[Kevin108]

When I wired offroad lights on a lightbar for my truck, I drilled about a 1/4" hole in the roof and used a weatherproof trailer wiring harness so I could disconnect the wires and remove the lights if I needed to. This has come in handy for parking garages over the years. All I had on hand at the time to seal the whole was blue RTV. It's been 5 or 6 years now and it has never leaked.

 

[xj_mike]

Have you installed this connector Mike?

Not yet. I haven't had any time to build my rack and light setup. I am deep into my '68 C10 truck project but hoping to get some build time for the XJ in the next couple months. I'll update things when I get to this point.

 

[StanBo]

Not yet. I haven't had any time to build my rack and light setup. I am deep into my '68 C10 truck project but hoping to get some build time for the XJ in the next couple months. I'll update things when I get to this point.

HA! we are moving in the opposite direction. I want to finish this truck so I can snag a C10!

I am moving along looking up information for this install. Can't wait to get my lights on the roof.