Radio Antenna Replacement Question

[tucsonjwt]

My 83 C20 has an aftermarket antenna mounted on the passenger side fender.
The cable for the antenna is routed into the engine compartment, under the cowl screen, then down under the dash.
I can't see how to remove the antenna mounting base on the fender - there is no obvious access to grab the underside of the mounting bracket. Must the fender be removed just to replace the antenna? I don't know if the 83s had a fender mounted or "in the windshield" antenna from the factory.
Also, what would be a proper antenna to replace it and where can I get it? I like the new style screw off antennas, but I don't know if they are compatible with the cable connection I currently have.
Thanks.

[RandyP]

Pictures of the aftermarket antenna? Lots of older aftermarkets went on similar to a toggle/molly bolt in drywall. Others just had one leg under them that would grab on to the metal of the fender, and you could loosen the base and worm it out through the same hole. There should be enough room to get your hand up in there though, through the backside of the fender in one of the large openings.

Factory style fender mounted antenna is the cable, a base that is screwed to the fender with three screws, a trim cap and then the mast itself. I can upload photos tomorrow of the factory setup, I have one laying on my bench at work ready to be installed on my 87, get rid of the horrid windshield antenna.

http://www.lmctruck.com/icatalog/cc/full.aspx?Page=164 in case it helps any. Their picture really does not resemble the factory mounts that I am used to seeing on the 85 and up squares.

[tucsonjwt]

I was able to turn the antenna base and tighten it to the fender, but it still looks bad. I am reluctant to try to pull it out through the top and possibly loose something that is attached to the underside. As you can see, there is no room to grab under the fender - the openings in the fender are to far forward.
Do the LMC antennas require you to have access under the fender?
If I remove the cowl and screen, is there access to the fender from there?
Thanks.
Here are some pics:

[RandyP]

It does appear they installed it a bit farther back than normal, and the routing they took with the cable appears you will have to R&I the fender. Looks like a simple screw on base with a plate under it. If you're going to replace it anyways, what's there to lose, loosen it up and see if it will come out after it is unscrewed a bit. Then maybe you can unplug the feed wire and poke it back out the fender. But it sure looks like they have it sorta pinched under the fender.

[tucsonjwt]

Thanks for the feedback. I turned the base and it seems to have two metal clips with 3 serrated teeth looking up at me. The problem is that when I turn the base to tighten it up - it loosens up again a few days later. I really don't want to remove the fender at this time - I only got to this point because I am installing a new dash cap and thought this would be a good time to get at my aftermarket stereo to install a new antenna - since the dash area is all open.
The antenna does provide good reception, so I guess I will wait until I get the outside of the truck repainted (if ever) and replace it then.

[RandyP]

Ok, I guess I had one too many last night. Let me correct myself, doh. You will not have to remove the fender, not by any means. Where they fed the antenna wire, it will feed back through with no issue at all, is a fairly decent sized gap there. Even if you did remove the fender, you still would not have access. Chances are you can undo the existing base, and unplug the wire, easy stuff from there. Here are photos of a factory style antenna, and the holes where they feed. You'd have to make some holes, but is not hard to do at all. The trickiest part is getting the antenna cable fed through the inner fender and out the top hole on the fender, a coat hanger will help a lot though.

Help with the pictures: #1 is the antenna, plate on bottom, base in middle (wire and mast hook to this), cap. #2 is the factory hole area on the fender. #3 is the hole in the inner fender where the antenna wire is fed through, factory cable has a rubber grommet to seal up the hole. #4 is the hole in the firewall where it is fed through to the interior, also another rubber grommet on that. Hope any of this helps! Again there is no reason to remove your fender.

[thrtsxchambers]

That's interesting, my truck had the antenna in the cowl. I got rid of it and used the windshield one and seems fine. I never knew it should be on the fender, learn more everyday.

[BLE 'BURBAN]

My '90 Suburban has a factory fender mounted antenna. last month I had the windshield replaced with one out of my old '81 crew cab that has the antenna in it. Hooked both antennaes together with a "Y" adaptor and now I'm able to get about another 50 miles of reception up here in the Chugach Mountain range

[tucsonjwt]

Thanks Randy. So, this whole operation mounts from the top, and 3 small screws hold it to the fender (fastened from the top of the fender) and the whole works is covered up with a rubber boot? Then the antenna cable just fishes out a 1.5" diameter hole in the inner fender and into a .5" diameter hole in the firewall next to the heater box?
This kinda makes my hacked up aftermarket one look sleek.
I think I would prefer the modern thin black antennas that screw off easily from the outside, but I guess it would be the same kind of installation - some sort of mounting from the topside - I guess.