81 Power Antenna Questions

[agildawg]

After MONTHS of shoppng and reading forums, I just got an 81 and am working thru all of the bugs. The power antenna was non-functional. A previous owner had cut the wires at the antenna. After removing it, I was able to determine that the motor works when power is applied (thanks to previous posts), but the middle section of the mast is bent so I will need a whole new mast, not just the repair piece with the top section. Are there any masts out there to be found? Any masts compatible from other chevys? Also, I drilled out the rivets on the motor cover, but still cant get it apart. Something seems to be holding it together in the center of where the gear is. Any tricks to getting it apart without breaking it?

If I can't get it repaired, do you guys have any recommendations on replacements? There seem to be a wide array of options, some that are direct replacements for about $180, and then some much cheaper. If it matters, it currently has an old (but non-original) delco am/fm/cassette in it that I plan to replace with an aftermarket unit. Will my plans to replace the radio affect what I do with the antenna? Rik's Vet has an antenna that will plug right in, but they say it only works with Original radio and antenna. I know about having to bypass the antenna relay if you put in an aftermarket antenna, but if the antenna is working properly, what is the issue with an aftermarket radio controlling it?

Thanks for any help you can give to an excited newbie!

Regards,
Ron

 

[TMPJoe]

well i am sure its the same set up as my 1980.

i am using a replacement antenna OEM from a wrecked 1979 some years ago... probably 9 or 10 years!

I have an alpine radio in my car.... no issues at all... (well other than someone blowing up the speakers!)

I have no idea why the antenna would not work with another radio..... you do have to be careful wiring it in in order to have the antenna go up and down with power on and off at the radio but that is not rocket science ...

 

[gmjunkie]

After MONTHS of shoppng and reading forums, I just got an 81 and am working thru all of the bugs. The power antenna was non-functional. A previous owner had cut the wires at the antenna. After removing it, I was able to determine that the motor works when power is applied (thanks to previous posts), but the middle section of the mast is bent so I will need a whole new mast, not just the repair piece with the top section. Are there any masts out there to be found? Any masts compatible from other chevys? Also, I drilled out the rivets on the motor cover, but still cant get it apart. Something seems to be holding it together in the center of where the gear is. Any tricks to getting it apart without breaking it?

If I can't get it repaired, do you guys have any recommendations on replacements? There seem to be a wide array of options, some that are direct replacements for about $180, and then some much cheaper. If it matters, it currently has an old (but non-original) delco am/fm/cassette in it that I plan to replace with an aftermarket unit. Will my plans to replace the radio affect what I do with the antenna? Rik's Vet has an antenna that will plug right in, but they say it only works with Original radio and antenna. I know about having to bypass the antenna relay if you put in an aftermarket antenna, but if the antenna is working properly, what is the issue with an aftermarket radio controlling it?

Thanks for any help you can give to an excited newbie!

Regards,
Ron

It can probly be fixed!!! Where are you in NC??I can still get antenna masts for C-3's,I may have one but I would have to look at it to see!!

 

[agildawg]

It can probly be fixed!!! Where are you in NC??I can still get antenna masts for C-3's,I may have one but I would have to look at it to see!!

I am in Raleigh and would love to simply repair it with a new/used mast and the new top section with the nylon cord. I still need to get the motor housing apart I assume to hook up the new cord. Anybody have any ideas on that? You guys are a GREAT source of information!

Thanks again!
Ron

 

[gmjunkie]

I am in Raleigh and would love to simply repair it with a new/used mast and the new top section with the nylon cord. I still need to get the motor housing apart I assume to hook up the new cord. Anybody have any ideas on that? You guys are a GREAT source of information!

Thanks again!
Ron

Actually it is best to have it in the car,It's almost Imposable to get it apart with the mast and cable still in it!!!Are you talking about the steel tube above the motor being bent,or just the antenna mast??Got a photo??

 

[agildawg]

Actually it is best to have it in the car,It's almost Imposable to get it apart with the mast and cable still in it!!!Are you talking about the steel tube above the motor being bent,or just the antenna mast??Got a photo??

The steel tube (above the motor but below the fender) appears fine. The mast, the telescoping part, is the only part I think I need, but I will need all 3 sections of the telescoping mast. I understand the top section is the one connected to the cable, and I will need that, but I will also need the lower 2 sections because there is a bend in it that I can't get out. I made it a lot better, but I think it is still not smooth enough for the motor to push it up and down.

I've attached a picture of the part I think I need, the mast, but will still need help to get the cable from the mast connected to the motor. I assume based on other posts that I needed to get the motor housing apart to hook up the new cable. tried to attach additional pictures, but they were too big. After taking off the clips on the housing, and drilling out the rivets, there still appears to be something holding the housing together at the gear.

Thanks again everyone for all of the help!

Ron

 

[mkapp7879]

Did you drill out the center of the round section? I may have the mast sections if you can't find a new assembly, but I need to look first. I know if I still have it the chrome is slightly worn, tho.

 

[agildawg]

Did you drill out the center of the round section? I may have the mast sections if you can't find a new assembly, but I need to look first. I know if I still have it the chrome is slightly worn, tho.

I didnt drill out the center of the round section. I did drill out 3 other rivets. Do I need to drill out a rivet in the center also? I was afraid it might mess up the gears or bearings if I drilled it out. Let me know if you have the mast section. I can't find any new ones anywhere. I working bur slightly worn one will be better than my bent one that doesn't work.

Thanks everybody!
Ron

 

[mkapp7879]

Yeah, you need to drill out that center one. I looked and I found the mast sections. They are actually for 78-early79 antennas but should fit the later plastic slimline model. I say that because the later mast sections DO fit the earlier antennas but are about 1/4" longer. I don't think these being a bit shorter will be any problem. I did shorten the longer late mast sections when I fit them to my 78 power antenna only because it parked a little above the grommit. Found a later replacement GM antenna on ebay cheap(like $14!)and cannibilized it. Just gave that motor to another guy last month. Do you have the nylon replacement leader for the repair? You can have these 2 mast sections free and I have a new nylon leader I'll sell for $25 if you need it.

 

[agildawg]

Yeah, you need to drill out that center one. I looked and I found the mast sections. They are actually for 78-early79 antennas but should fit the later plastic slimline model. I say that because the later mast sections DO fit the earlier antennas but are about 1/4" longer. I don't think these being a bit shorter will be any problem. I did shorten the longer late mast sections when I fit them to my 78 power antenna only because it parked a little above the grommit. Found a later replacement GM antenna on ebay cheap(like $14!)and cannibilized it. Just gave that motor to another guy last month. Do you have the nylon replacement leader for the repair? You can have these 2 mast sections free and I have a new nylon leader I'll sell for $25 if you need it.

Wow! Thank you very much. I think that will work out perfectly to repair my antenna. If by the nylon leader you mean the top section of the antenna mast with the cable attached, that slides up thru the other 2 sections, then I will need that also. I'll need one for an antenna without CB. If that's what you've got, then we are in business. I'll also probably need a little guidance in how to hook the nylon leader into the gear from the motor. Just let me know how you want to proceed.

Thanks,
Ron

 

[mkapp7879]

Yeah. the nylon leader is the piece with the top mast section attached. I have one of those, non CB, pretty good instructions included in the package. I did some checking on my Vettes. Make sure your existing antenna is the factory original, not the "GM service replacement"(as on my white 79). These mast sections I have are thicker than the service replacement mast and won't work with it. The way to tell the difference is the factory antenna has an end on the main tube that kinda fits into the fender hole and the service replacement has 4 prongs on the end and is a little ill fitting. Here's an easy check. If you have a set of drill bits in a drill index, the middle mast section should slip into the 13/64 slot, the big mast section into the 5/16" slot. If this checks out, PM or email your info and I'll send it out. You can pay me the $25 plus actual shipping when you get it. Mike
edit. make it $22 + shipping. That's what it will cost me to replace it. I needed to order another one anyway but was putting it off because of the ridiculous shipping. Need 2 now, shipping doesn't look so bad for 2 at least!

 

[agildawg]

PM Sent. Thanks to all for their help. I'm sure more questions will be forthcoming. What a GREAT resource.

Ron

 

[GerryLP]

... The power antenna was non-functional. A previous owner had cut the wires at the antenna...

This is usually a sign that the antenna nylon chord broke on the way down or retract mode. When it breaks, the motor will keep going until it burns-out or the battery runs-out. A lot of times, one only has the time to cut the wires, since unplugging the harness would require to remove the driver-side rear speaker, and reach under the carpet and disconnect the harness. The connector is in the cabin side of the harness wall plug. It happens to an average share of C3 Vette owners.

On the antenna motor casing, there are metal clips evenly spaced throughout the casing flange. Once you find them all (I believe that there are 5 or 6 of them). You can use a putty knife to separate the two haves. When you do this, keep your fingers out of the way, and slip the putty knife in between the casing and push it along and in between the flange AWAY FROM YOUR BODY!

Whenever you replace the nylon chord and mast, hold the casing halves with the clips, and test it out with a 9 volt battery. It has enough juice for about one or two cycles (deploy and retract = one cycle). If it works, you'll have to carefully separate the motor housing and seal it with white RTV. Good luck!

 

[GerryLP]

By the way, if anyone has the load coil for the CB antenna mast, I am looking for one.

 

[agildawg]

With many thanks to MKapp7879 for supplying an antenna mast and some basic instructions, the power antenna is now fully functional. If anyone has questions on how to go about repairing the antenna, let me know since I just went through it. Thanks again to everyone.

 

[shaner238]

I am in need of whatever parts are necessary----my antenna won't go down but motor keeps on running. It iss now unplugged 81