Haunted 84?

[Walter G.]

Tonight I'm getting the garbage cart from the garage to bring it to the curb and her a humming sound. I figure it's coming from the garage furnace since it's been -0 here lately. I went to check and it's not coming from the furnace but from the '84. The power antenna motor is running. (the car has been stored since Nov. 1st under a cover with a battery tender) I finally pulled the fuse, as it wouldn't shut off by turning the radio off/on or any other means. The antenna must have raised partway and stopped-due to the car cover i'm sure-and it won't go back down manually. (I didn't try forcing it)
Any thoughts what caused this? Any easy fix? (doubtful) Anyone else experience something similar?

[David H.]

Re: Haunted 84?

Tonight I'm getting the garbage cart from the garage to bring it to the curb and her a humming sound. I figure it's coming from the garage furnace since it's been -0 here lately. I went to check and it's not coming from the furnace but from the '84. The power antenna motor is running. (the car has been stored since Nov. 1st under a cover with a battery tender) I finally pulled the fuse, as it wouldn't shut off by turning the radio off/on or any other means. The antenna must have raised partway and stopped-due to the car cover i'm sure-and it won't go back down manually. (I didn't try forcing it)
Any thoughts what caused this? Any easy fix? (doubtful) Anyone else experience something similar?

Walter,

Below is copy from a CF post. Perhaps this is your issue as well - broken cable.

Dave

"The motor runs constantly on a broken antenna, because the internal flexible cable is broken. The cable is wrapped around a drum inside the casing. When the ant goes down as far as it can it pulls the cable tight which actually moves the whole motor a tiny bit against a spring. This opens the "down" contact and cuts the power. Then when you put it up, it reaches the top and the flexible cable gets "compressed" wrong word really, but if you can imagine it cant go anywhere 'cos its inside the narrow aerial. This again moves the motor a little but in the opposite direction, and opens the "up" contact, cutting the power. But if your flexible cable is broken, then the motor thinks the aerial has never gone right up or right down and just keeps on turning. That's why someone's pulled the plug on it! Yes you can get a new flexi cable to fix it...I got one from Ecklers for less than $20. Not too bad a job to do."


Link:

https://www.corvetteforum.com/forums...na-1980-a.html

[Walter G.]

Re: Haunted 84?

I understand what is likely damaged, but the main question is what caused a dormant antenna motor to suddenly power up? The car has not been moved/started in 3 months. The radio was off when I checked after uncovering it so the antenna tried to rise without the radio being on, which is not supposed to happen. Replacing the flexible cable is one thing, but will the random startup occur again? An electrical short? Rodents? Vehicle passing by with a frequency that matched? The battery tender still flashes like usual. Just very odd...

[David H.]

Re: Haunted 84?

I understand what is likely damaged, but the main question is what caused a dormant antenna motor to suddenly power up? The car has not been moved/started in 3 months. The radio was off when I checked after uncovering it so the antenna tried to rise without the radio being on, which is not supposed to happen. Replacing the flexible cable is one thing, but will the random startup occur again? An electrical short? Rodents? Vehicle passing by with a frequency that matched? The battery tender still flashes like usual. Just very odd...

Walter,

If your wiring is similar to later C4, then antenna motor power is supplied constantly from LH Courtesy Lamp fuse (probably 20 amp). (RH Courtesy lamp fuse is most likely 5 amp.) As outlined in prior post, in normal up/down antenna operation switches motor off at travel limits - broken plastic cable does not allow switch off to occur.

Normal operation: with ignition on, radio on signals Antenna Relay coil to energize - moving relay contacts and antenna extends. With radio or ignition off, relay coil is de-energized and antenna retracts.

Perhaps an autopsy of motor unit will reveal if where that plastic cable snapped triggered your runaway. Later C4 antenna motors have an integral relay - don't know about 1984.

Dave

[Walter G.]

Re: Haunted 84?

OK, that would make sense. The plastic cable must have just randomly snapped sending the relay to the 'up' mode despite the radio not being turned on. Not sure how long the motor was running, but it had to be several hours before I was in the garage to hear it. Based on that I'll try to buy a complete replacement antenna unit and not deal with using a motor that currently works but has likely been compromised by running constantly for an extended period. I don't want to tackle this job twice!