Another antenna failure - ZR-1 Net Registry Forums

mlipmd · 12-25-2022

I have a '90 ZR-1, #545. It's been really cold (lows of 20s last few nights), and I went for a ride yesterday with the temp about 36-38, turned on the radio, and when I got out of the car I noticed the antenna didn't retract when the power was shut off. Turning it on and off again on the ride home, it still would not retract with the power off. I can push it down in about 4". then it stops, can push either the top or bottom section in that far. It pulls back up real easy, like the shaft isn't connected to anything. I wonder if the cold made the 32 year old cable brittle and it cracked or broke when it tried to go down.
I have read somewhere that there were 2 types of cables that were used before the design changed during the early Zs. One is a straight nylon cable with a sort of hooked end that goes into the spool, the other a cog-toothed cable that engages teeth on the spool. Can anyone tell me which one I may have for my car so I don't look for and purchase the wrong one to try and repair this?
I first have to get my SO to turn on and off the radio and try and listen if the antenna motor is running, then I know for sure if the problem is with the cable. I'm really hoping I can replace this from above without having to remove the rear wheel, fender liner, disconnect the wiring and antenna cable, and remove the whole mechanism and take it apart to fix this, as all that is a real PIA and time consuming. If it's the cog-toothed cable I should be able to do this, and hopefully pull all of the broken cable out, but if I have the smooth hooked-end cable, I guess I will have to bite the bullet and remove the whole thing. And it's still cold here in the panhandle of Florida.

Addendum - the motor runs when the radio is turned on, it does not run when the radio is turned off.

secondchance · 12-25-2022

Successfully feeding replacement antenna and it?s cable from the top is hit or miss ordeal based on my experience. I suspect that it depends on how long a cable broke off inside and stays inside.
I believe 3 - 4 times I did this, I was able to remove the antenna assembly with out removing the wheel and inner liner.
As for different type of toothed cable, I think 90 thru 95 are the same. Early C4s, 84 to maybe 87 or so look different externally and may have different antenna/cable.

mlipmd · 12-26-2022

You must have a lift to be able to get under there to remove the entire antenna assembly without taking the wheel and fender liner off. I don't have that luxury.
What year C4s did you do this to and what type of cable was it, the toothed one?

Mystic ZR-1 · 12-26-2022

It only takes a few minutes to remove the LR wheel
and a few more to remove the liner.... no lift needed.
Please use a jackstand or 2!

mlipmd · 12-27-2022

A follow-up ----

I was able to grab and turn and remove the nut without removing the grommet, using a 90 degree needle nose pliers which seemed perfect for the job.
The whole antenna and cable just came right out without any resistance or pulling at all.
I cannot tell if the cable had snapped, the end does not appear to have recently broken, it and the rest of the cable have some black grease on it which looks fairly good, not dried out or hard.
With the antenna fully retracted the cable measures 36" from the lower end to the tip of the antenna, with the antenna fully extended there is 3" of cable sticking out at the bottom end. There are no teeth missing from the cable and it doesn't appear to be worn down or smoothed out.
Does anyone know how long this cable is, or should I just try to rethread it into the motor and see if it grabs and works? Could the end of my cable just have come off the spool?

I think I found out why my radio reception is so poor and staticky (a word?). The lower collar is supposed to be the electrical connection to the antenna, mine is covered in black grease and those little projecting tabs are flush with the collar instead of bending outwards to contact the sleeve inside the grommet. Well see how it works after I clean it up and get it reinstalled.
The poor reception is probably not related to the HU because that was completely redone and CDs and cassettes play perfectly clear and sharp.

mlipmd · 12-27-2022

I just spoke to a sales rep at zip corvettes and she got one off the shelf and measured the whole thing tip to tip and got 49 1/2" with the antenna extended, or 16" of cable sticking out of the bottom when extended. So I guess my cable has snapped somewhere about a foot from the end and that is inside the mechanism. If I turn on and off the radio, the motor will run for 3 sec. or so each way and then stop by itself, no cable gets spit out, it must be stuck in there or wound up on the spool. I can't see any way of fishing it out so I guess I have to bite the bullet and drop the whole motor and open it up.
BTW, if I stick my cable in 'till I hit bottom, it won't get grabbed by the teeth on the spool so I have no choice (other than just sticking the antenna back in and leaving it up, 'till someone comes by and breaks it off).

mlipmd · 01-08-2023

Final follow-up -
I was able to fairly easily remove the antenna motor assembly from underneath the car after jacking it up 6" or so and supporting the car with a jackstand and a 6x6 block underneath the pinchweld seam, and having the rear tire rest on a number of short pieces of 1 1/4" board (nothing like being too safe). The assembly only really required removal of two hex bolts securing it to the support bracket and removal of one Phillips head screw from a grounding cable. Then just gently pull and slightly rotate the unit down through the grommet on the fender.
I could pull it down far enough without removing any electrical supply wires or the antenna cable to remove the three Phillips screws holding the case together and easily remove the broken segment of cable inside. Then it took another 2-3 min. to place it back in position and screw it back in place. As an aside I could clean up the ground connection which improved my reception a bit with a little less static.
The hardest part of the whole repair was to get the cable to grab and get itself pulled inside the case, which took a few times of manipulating it and pushing it in until the cogged wheel grabbed it.
Overall the job was actually quite easy, the longest part of it was to jack up the car and get all the supports in place for safety.
I see no reason to remove the wheel and fender liner, the access from below is quite easy and the exposure and visibility could not be better.
So for the time being, now I'm happy 'till the next thing eventually happens.

hiperf406 · 01-15-2023

I used to park my ZR1 under a hoist in my garage & I would forget to shut radio off so antennae would retract. Several times I would pull in & then realize my antenna was up it would bend up the mast & I straightened it out best I could but still sticky.

WARP TEN · 01-16-2023

Quote:

Originally Posted by hiperf406

I used to park my ZR1 under a hoist in my garage & I would forget to shut radio off so antennae would retract. Several times I would pull in & then realize my antenna was up it would bend up the mast & I straightened it out best I could but still sticky.

Ha Ha--me too. Posted a "LOWER ANTENNA" sign on the lift eventually and didn't hit afterwards. --Bob

AirbusDriver · 01-18-2023

Quote:

Originally Posted by WARP TEN

...Posted a "LOWER ANTENNA" sign on the lift eventually and didn't hit afterwards. --Bob

That's using yur head😁

12-25-2022	#1
mlipmd Join Date: Mar 2021 Location: Crawfordville, FL Posts: 200	Another antenna failure I have a '90 ZR-1, #545. It's been really cold (lows of 20s last few nights), and I went for a ride yesterday with the temp about 36-38, turned on the radio, and when I got out of the car I noticed the antenna didn't retract when the power was shut off. Turning it on and off again on the ride home, it still would not retract with the power off. I can push it down in about 4". then it stops, can push either the top or bottom section in that far. It pulls back up real easy, like the shaft isn't connected to anything. I wonder if the cold made the 32 year old cable brittle and it cracked or broke when it tried to go down. I have read somewhere that there were 2 types of cables that were used before the design changed during the early Zs. One is a straight nylon cable with a sort of hooked end that goes into the spool, the other a cog-toothed cable that engages teeth on the spool. Can anyone tell me which one I may have for my car so I don't look for and purchase the wrong one to try and repair this? I first have to get my SO to turn on and off the radio and try and listen if the antenna motor is running, then I know for sure if the problem is with the cable. I'm really hoping I can replace this from above without having to remove the rear wheel, fender liner, disconnect the wiring and antenna cable, and remove the whole mechanism and take it apart to fix this, as all that is a real PIA and time consuming. If it's the cog-toothed cable I should be able to do this, and hopefully pull all of the broken cable out, but if I have the smooth hooked-end cable, I guess I will have to bite the bullet and remove the whole thing. And it's still cold here in the panhandle of Florida. Addendum - the motor runs when the radio is turned on, it does not run when the radio is turned off. Last edited by mlipmd; 12-25-2022 at 01:30 PM.

12-25-2022	#2
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,703	Re: Another antenna failure Successfully feeding replacement antenna and it?s cable from the top is hit or miss ordeal based on my experience. I suspect that it depends on how long a cable broke off inside and stays inside. I believe 3 - 4 times I did this, I was able to remove the antenna assembly with out removing the wheel and inner liner. As for different type of toothed cable, I think 90 thru 95 are the same. Early C4s, 84 to maybe 87 or so look different externally and may have different antenna/cable.

12-26-2022	#3
mlipmd Join Date: Mar 2021 Location: Crawfordville, FL Posts: 200	Re: Another antenna failure You must have a lift to be able to get under there to remove the entire antenna assembly without taking the wheel and fender liner off. I don't have that luxury. What year C4s did you do this to and what type of cable was it, the toothed one? Last edited by mlipmd; 12-26-2022 at 04:05 PM.

12-26-2022	#4
Mystic ZR-1 Join Date: Jan 2010 Location: Mystic CT Posts: 2,594	Re: Another antenna failure It only takes a few minutes to remove the LR wheel and a few more to remove the liner.... no lift needed. Please use a jackstand or 2!

12-27-2022	#6
mlipmd Join Date: Mar 2021 Location: Crawfordville, FL Posts: 200	Re: Another antenna failure I just spoke to a sales rep at zip corvettes and she got one off the shelf and measured the whole thing tip to tip and got 49 1/2" with the antenna extended, or 16" of cable sticking out of the bottom when extended. So I guess my cable has snapped somewhere about a foot from the end and that is inside the mechanism. If I turn on and off the radio, the motor will run for 3 sec. or so each way and then stop by itself, no cable gets spit out, it must be stuck in there or wound up on the spool. I can't see any way of fishing it out so I guess I have to bite the bullet and drop the whole motor and open it up. BTW, if I stick my cable in 'till I hit bottom, it won't get grabbed by the teeth on the spool so I have no choice (other than just sticking the antenna back in and leaving it up, 'till someone comes by and breaks it off).

12-27-2022	#5
mlipmd Join Date: Mar 2021 Location: Crawfordville, FL Posts: 200	Re: Another antenna failure A follow-up ---- I was able to grab and turn and remove the nut without removing the grommet, using a 90 degree needle nose pliers which seemed perfect for the job. The whole antenna and cable just came right out without any resistance or pulling at all. I cannot tell if the cable had snapped, the end does not appear to have recently broken, it and the rest of the cable have some black grease on it which looks fairly good, not dried out or hard. With the antenna fully retracted the cable measures 36" from the lower end to the tip of the antenna, with the antenna fully extended there is 3" of cable sticking out at the bottom end. There are no teeth missing from the cable and it doesn't appear to be worn down or smoothed out. Does anyone know how long this cable is, or should I just try to rethread it into the motor and see if it grabs and works? Could the end of my cable just have come off the spool? I think I found out why my radio reception is so poor and staticky (a word?). The lower collar is supposed to be the electrical connection to the antenna, mine is covered in black grease and those little projecting tabs are flush with the collar instead of bending outwards to contact the sleeve inside the grommet. Well see how it works after I clean it up and get it reinstalled. The poor reception is probably not related to the HU because that was completely redone and CDs and cassettes play perfectly clear and sharp.

01-08-2023	#7
mlipmd Join Date: Mar 2021 Location: Crawfordville, FL Posts: 200	Re: Another antenna failure Final follow-up - I was able to fairly easily remove the antenna motor assembly from underneath the car after jacking it up 6" or so and supporting the car with a jackstand and a 6x6 block underneath the pinchweld seam, and having the rear tire rest on a number of short pieces of 1 1/4" board (nothing like being too safe). The assembly only really required removal of two hex bolts securing it to the support bracket and removal of one Phillips head screw from a grounding cable. Then just gently pull and slightly rotate the unit down through the grommet on the fender. I could pull it down far enough without removing any electrical supply wires or the antenna cable to remove the three Phillips screws holding the case together and easily remove the broken segment of cable inside. Then it took another 2-3 min. to place it back in position and screw it back in place. As an aside I could clean up the ground connection which improved my reception a bit with a little less static. The hardest part of the whole repair was to get the cable to grab and get itself pulled inside the case, which took a few times of manipulating it and pushing it in until the cogged wheel grabbed it. Overall the job was actually quite easy, the longest part of it was to jack up the car and get all the supports in place for safety. I see no reason to remove the wheel and fender liner, the access from below is quite easy and the exposure and visibility could not be better. So for the time being, now I'm happy 'till the next thing eventually happens.

01-15-2023	#8
hiperf406 Join Date: Apr 2007 Location: Spruce Grove Oilberta/In Mex for winter Posts: 1,046	Re: Another antenna failure I used to park my ZR1 under a hoist in my garage & I would forget to shut radio off so antennae would retract. Several times I would pull in & then realize my antenna was up it would bend up the mast & I straightened it out best I could but still sticky. __________________ lorne # 1748 Stock except for a modified Corsa exhaust. When the flag drops the bull sh1t stops!