1978-1987 Corvette Power Antenna Mast Repair Kit

trevbeadle

CCCUK Member
Has anyone used one of these mast kits to repair a standard factory power antenna on a C3 (mine's an '80)? My antenna motor obviously ran continuously until Bubba cut the feed wire near the motor under the rear wheel-arch.! I've removed the whole lot and stripped it, the motor runs perfectly when connected to a remote battery. I've opened up the unit and sure enough the nylon operating cable is broken just near the end on the drive sprocket. about 10cm from the hooked end. The rest of the cable and top part of the mast is missing. From the pictures I see of the Kit, the nylon cable comes fixed to a new top past of the mast. I'm concerned that a section of the mast that remains on my old unit is 'missing' one of the sections, in which case the kit will be useless. Can someone confirm from their experience and my photos that this is the case and if I will be wasting my time buying a repair kit?

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Corvetteville

CCCUK Member
Are there more telescopic sections inside the main antenna case? If that's the only section, then there's some missing & a kit won't do it.
Some years ago I did a repair on my C4 antenna with a kit. The mast part was complete with 3 sections, & apart from not rising & retracting, was OK. The plastic track was broken & worked fine after repair.
The antenna on my C3 only had the lower, largest mast part remaining, so a kit was no good.
I bought a £20 UK complete antenna. I took the old one to a good spares shop to compare. If it's got 3 wires your good to go.
Check the mounting holes will line up on your bracket & the top body nut is adjustable to allow for the slope of the rear wing. Make sure it's earthing. My new one had a relay mounted on it, I didn't know if the car relay was good, so I bypassed the it by snipping it out of the loom & reconnecting with crimp & shrink connectors. It's under the central console on a 78, between the shifter & parking brake. Hope that helps.
 

trevbeadle

CCCUK Member
Same as yours, Corvetteville, only the lower largest part remaining. Looks like the repair kit is a no no!
I bought a replacement electric, but it only has an earth plus red and green, which from its wiring diagram shows connected to the radio. I fear the corvette wiring (and I'm not too good with electrics) is not compatible. I extended and checked the 3 wires under the wheel arch, a green, grey and white wires. Earth is a separate braided strip. There is 12 volt constant from the grey. but no reading at all from the white or the green regardless of ignition or radio on/off. I believe all 3 come from a relay in the RH storage box behind the passenger seat on an '80. The green wire had been cut next to the antenna body, before when I reconnected it the old motor ran continuously (I surmise an earth connection from the relay?) but this new one won't work at all !. I certainly don't intend to spend £224.34 + postage with Corvette Kingdom for a new power antenna!!! Who listens to the radio when driving anyway!! I've plenty of cassettes that still do if I need music, Maybe I'll do a Bubba fix and just connect up a manual mast! The radio did pick up signals (faintly) when I pulled up the stump of the old electric one.
 

Corvetteville

CCCUK Member
Hi trevbeadle, been quite a while since I did it & the old grey cells have vamoosed! LOL. 3 wires from the car sound right & if the old motor runs, then the power is present. I would think it's earth on the new one. Most antenna would earth through the wing at the top, but can't on a Vette. If there is a metal insert in the base where it screws onto the bracket that may do it. Put a ring connector on a short wire from there to something attached to the chassis. Or take it off the main shaft to earth. To start, get a piece of wire and touch from any metal on the new antenna body to the chassis. I'll try to have a look at mine tomorrow & see what I did, can't remember, DOH!! LOL 🤣
 

Corvetteville

CCCUK Member
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Hi Trev. Have look at this, it's basically what I did. The new antenna needs a constant power (you've got that) & switched power (from radio)
1.Check the radio is for an electric antenna (needs a switched power output) if it's original it should have.
2.Bypass the car relay, (your new antenna should have a built in relay)
The switched power puts the antenna up, & when broken, it goes down
I think your main issue will be the original relay not needed. Steve.
 

trevbeadle

CCCUK Member
Thanks Steve,
Checking under the rear wheel arch, I think the problem is no power from the 'switching' green wire when the radio goes 'on'. The new power mast works ok remotely now I've fathomed it, 12v constant to red, power mast up when the green to power also. Motor stops when up and stays up until the green 'breaks power' then it goes down. The next check I think is radio out of the centre console and see if it has a 'switching' wire fitted. Its not the original but an '80's radio/cassette. All the wiring/plugs/relays seen to be intact in the cubby box in rear. Things will have to wait as over the next 2 weeks or so the 'vette will have live in the garden tarp'ed up while I renew the carport roof!! I'll repost when there's progress!
 
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