Where to drill hole to under Suburban hood for hood mount?

[sefrischling]

I have always had my antennas installed on the roof, and now am installing one on the hood of my 2002 GMC Yukon XL (same as a Suburban, Tahoe, 1500/2500/3500 pick up).

Before installing the NMO mount I have been unable to find any guide on where to drill the hole to run the cable from under the hood into interior. Any suggestions on where to make the hole? I don't want to screw anything up. The more detail the better ... I don't feel like screwing something up under there.

The mount will be on the driver side of the truck.

Also ... any tips on sealing the hole? I planned on using the basic silicon sealant I use with the roof NMO mounts.

Thanks!

 

[ridgescan]

Why not get the "RV mount"- an "L" bracket type that bolts inside the front fender, protrudes out between the fender/hood so that the antenna base resides just over the top of the fender? You still get the hard grounding without having to drill.
http://www.hamradio.com/detail.cfm?pid=H0-003453

 

[SCPD]

hood antenna

When you get your Antenna installed , run the antenna cable up to your fire wall & through the fire wall where the steering wheel shaft is, there is a rubber boot there for the steering wheel shaft, you can pull back the rubber boot enough to run the cable through it to hook it to you radio. Good luck !

 

[mmckenna]

I think he's asking about getting through the firewall.

It's been a while since I worked on one of those, and even then we installed the antennas on the roof, only running power feed through the fire wall. Back then, I'm pretty sure I remember either using an existing grommet, or following other wires through. Most newer vehicles have double walled fire walls, and things tend to be a bit tight, both under the hood and under the dashboard.
The benefit to vehicles based off full size trucks is that manual transmissions are an option. This usually means there are places where the clutch linkage would have passed through. Finding one of those plates might be a good option. Remove the plate and drill a hole in it and use that.
Other option is to find one of the larger grommets and see if you can either pass another wire through next to the others, or make a small incision on the side of the larger ones.

As always, make sure that everything has a grommet so the chance of a sharp edge abrading the cable is reduced. While it's only going to be coax, in your case, damage to the outer jacket can let water in, which will quickly destroy the cable. Following up with some RTV or silicone is a good idea.

 

[sefrischling]

Why not get the "RV mount"- an "L" bracket type that bolts inside the front fender, protrudes out between the fender/hood so that the antenna base resides just over the top of the fender? You still get the hard grounding without having to drill.
HUSTLER RVM | RV MOUNT W/ SWIVEL BALL,17' COAX

The hood mount makes the most sense for the antenna location. I am trying to reduce the height on my roof, leaving just the UHF and 800mhz antenna up there, with the considerably taller VHF/UHF dual band being moved to the hood.

I have no problem drilling the car, the roof has holes, so holes under the hood don't matter. Its a matter of convenience and practicality.

 

[sefrischling]

When you get your Antenna installed , run the antenna cable up to your fire wall & through the fire wall where the steering wheel shaft is, there is a rubber boot there for the steering wheel shaft, you can pull back the rubber boot enough to run the cable through it to hook it to you radio. Good luck !

Thanks, I need to go crawl under the hood and take a look. As unmechanical as I am, I am sure I can find the steering column ... I think :0)

 

[sefrischling]

mmckenna,

Thanks, the clutch-hole is probably under there somewhere. As far as I know it is exactly the same set up under there as the full-size pick ups.

 

[teufler]

around the steeting column there is a rubber seal. An ice pick makes a good hole. To will collaspe around the cable when you tun it though. You will install your antenna connector after the cable is pushed through the firewall. I know thia aounds dumb but crazyer things have happened when doing installs. Putting a pl259 around rg58 cable, soldering the cinnector on then realizing you forgot to put the reduced on the pl259 cablle first. The Lbracket, some you can find are stainless steel . The bracket usually attaches to the fender at a point opposite you car amfm anttenna. The antenna radiates pretty good though not as good as a location on the roof. With the antenna mounted on the driver side, you transmitt pattern will favor the passenger side of the car. Optimally, your signal on the left side of your vehicle will fall off .

 

[sefrischling]

Thanks Teufler.

This antenna is for receive only. I listen to specific things for work, and have found these antennas work best ... although I am always open to playing with ... err ... I mean testing ... new antennas.

 

[teufler]

Specfically, what antenna are you planning on mountin. Yes for monitoring the fall off will not be a big deal. There have been many discissions on "the best " antenna. Whats best is the one that works. I use an Austin Spectre but a 1/4 vhf antenna works pretty good for monitoring. Also is more discret. Sometimes this makes your installation better .People see you vehicle and wonder who that could be. Discretion is better than valor, slow down and let them pass, so to speak. One of the best discrete installs I have seen was someone mounted their antennas on the back deck,behind their rear seats inside the back glass. The antennas were rubber ducks or 1/4 wave vhf antennas. It had to be a federal unit, or at least it had me think it was a federal unit as most of the city or county cars are all outside antennas.

 

[sefrischling]

Teufler

I spent many years as a news photog, covering metro New York, where I covered the city, and multiple surrounding areas that alone have huge populations, I ran seven scanners, each with their own antenna. When I was the chief photog at a paper in New England I covered a corner where three states meet, which required eight scanners ... so I am not to worried about how many antennas i have. It is all about function.

Now I cover primarily transportation security, which involves a lot of different systems, since out of my car I can cover six states (everywhere else it is two radios, an antenna packed in my bag and a rental car) and work off three antennas. The antenna going on the hood will be a Tram 1181, it is fairly compact, picks up VHF and Low band failly well. Up top is a short 800mhz and 3.5" UHF whip.

I have tried the Austin Spectra, but a put off by its length and didn't see an advantage to it compared to what I know works. For the moment I just have two SpectrumForce Wideband Antennas, which do OK, they are pretty good for what they are, but are not a permanent solution. The 800mhz and short UHF are not really easily seen unless you're really looking for them up top on the truck.

 

[ofd8001]

Have you thought about getting a vehicle specific mount for your antenna? That way you won't have to drill holes to mount your antenna. These will attach to the fender.

I've got a Ford F150 and have two - one for my scanner, the other for my amateur radio.

On going through the firewall, there should be numerous rubber boots or other grommets you can use. Often a #2 phillips screwdriver is all it takes to get a poke-through hole started.

 

[sefrischling]

ofd8001

I am not interested in a fender mount, anything mounted to the fender for a 17" tall antenna will be destroyed fairly quickly.

 

[KB7MIB]

Wirelessly posted (Opera/9.80 (BREW; Opera Mini/6.0.3/27.2354; U; en) Presto/2.8.119 320X240 LG VN530)

Why not drill in the top of the fender, like the OEM broadcast antenna is mounted on top of the right front fender, instead of the hood? How would this location cause your mount/antenna to be destroyed anymore than the OEM antenna opposite it?
I would also think that the hood would be thicker, double-walled and/or have cross braces to deal with.
What about a trunk lip mount on the side of the hood? It'd be mounted to the hood, but no holes drilled.
I myself want a K2500 Suburban at some point, and that area would be where a scanner antenna would go.

 

[sefrischling]

KB7MIB

I know where the antenna is being installed, I just need to figure out where to run the coax.

 

[n0nhp]

I often found that if it was inconvenient to run through the clutch or steering grommet due to mounting on right side of vehicle and not wishing to pass the coax too near the exhaust, I could usually locate the heater air box and locate a clear place just under or to the side, drill my 1/4" hole and run the coax through, That size hole will require no additional sealing, not allow the coax to move enough to chafe through the jacket and if fished slowly and carefully, not damage the jacket. You may have to pull some of the soundproofing / insulation from the firewall to get to the metal to drill. Use a very sharp bit and as soon as you think you are even close to penetration back off on the pressure and just allow the bit to penetrate so you don't jam the bit through and hit something on the back side as well as leave razor sharp edges on the hole.
Do not run the coax across the hump under the insulation, with today's engines, that area gets hot enough to melt the coax.
I will probably catch flack about the size of the hole and no grommet, I only installed a couple of thousand radios in my years and never had a problem with the coax passing through the firewall in a quarter inch hole. I did learn about the coax under the insulation or crossing behind the engine the hard way however.

Bruce

 

[sefrischling]

Thanks Bruce. I didn't even think about the heat melting the wiring. Very good to know!

 

[KF4FVG]

I use an L bracket RV mount attached to the RF fender with screws hidden between the hood and fender near the grill for my 4 foot CB antenna on my older Suburban. It has been like that for at least 5 years without a problem. Best I remember, I ran the coax came through the firewall on the passenger side rubber grommet that was in the firewall.

 

[ridgescan]

LOL wut