Weird Sound Coming from Behind the Right Panel

[Jetjock]

After putting some screws in my right door, I heard a funny sound like a relay going back and forth at a very fast pace. I have never that sound before and I've owned C4's since 2002. I've taken C4's apart before including ZR-1's and the other Corvettes. I got my key and turn on the ignition and the DIC panel was dark and nothing on the main display. The sound did stop while I was doing that but started again when I turned the key off. I got out my volt meter and checked the voltage of the battery and it was normal as was the output of the battery tender. I shut the car door and it stopped. I'm going to check it in a few hours and see if it starts again. It's a 92 ZR-1.



Any idea what could be causing that?


Roy

[DRM500RUBYZR-1]

Those relays cycling normally are a result of a below average voltage condition.
While you state it was ok, leave it on a charger overnight and it will likely be gone in the morning.
:cheers:
Marty

[Jetjock]

Those relays cycling normally are a result of a below average voltage condition.
While you state it was ok, leave it on a charger overnight and it will likely be gone in the morning.
:cheers:
Marty


Actually, it's not ok. The battery voltage is ok but the car is acting like it's not getting any voltage at all and the battery tender is on all of the time. I had to replace the hatchback weatherstripping and that meant having the doors and hatchback open for a while. On an airplane, if the voltage drops below 22 volts, the bus tie won't connect and you can't get the main bus powered up even with a GPU. I'm sorry for the airplane analogy but that's experience that I have and obviously, more in depth that you needed.


It just acts like the battery can't connect to the car's electrical system which would explain the cycling back and forth. The battery is fully charged.



Roy

[DRM500RUBYZR-1]

Check your connections.
If that battery is showing full voltage still, ( although I suggest a load test) then start with the battery terminals and work outwards, checking the major points, checking for tightness and good clean connections.
Do you observe SYS on the instrument panel when this is happening?
If so, that is the CCM diagnostics indicating often a lower than required voltage condition.
Have encountered this on many C-4's, and it always has been related to low voltage, often the bolts in the cables.
Keep us posted of progress.
:cheers:
Marty

[WARP TEN]

As Marty suggests, check connections. I would stress including ground connections. Ground connections have been a frequent cause of issues in the ZR-1s, which are, after all, pretty old cars. Good luck with finding the cause! --Bob

[Jetjock]

Check your connections.
If that battery is showing full voltage still, ( although I suggest a load test) then start with the battery terminals and work outwards, checking the major points, checking for tightness and good clean connections.
Do you observe SYS on the instrument panel when this is happening?
If so, that is the CCM diagnostics indicating often a lower than required voltage condition.
Have encountered this on many C-4's, and it always has been related to low voltage, often the bolts in the cables.
Keep us posted of progress.
:cheers:
Marty


Ok. I checked the battery and the battery connections and they are good. Where would the other points be to be checked out? I don't have a lift so going under the car is not an option. No sys on the DIC.



Roy

[tiegsd]

Wondering if relay cycling is from under the hood, or in the cabin? On a 90 there are relays (4 I think, don't have my service manual or car handy at the moment) in the fuse box just inside the passenger door. If you can locate the cycling relay, might help.

[Jetjock]

Wondering if relay cycling is from under the hood, or in the cabin? On a 90 there are relays (4 I think, don't have my service manual or car handy at the moment) in the fuse box just inside the passenger door. If you can locate the cycling relay, might help.


It was from the right side of the cabin. I called Marc Haibeck and told him the voltage was 11.55 and he said that I had a dead battery. Ok, So I went out and bought the same kind of battery for the car. I put the battery in the car and started to put the battery cables on and they wouldn't tighten up. I realized that the receptacles were bigger than my battery connectors were. Up until now I thought that all battery connections were the same size. How many different sizes are there?


Roy

[DRM500RUBYZR-1]

Side terminal batteries, at least in the US all use the same size bolt for the connection.

Side Terminal Battery Bolt 3/8-16 Thread

If your bolts are not tightening either the wrong bolts are in the battery cables, they somehow have corroded and are now wrong, or the lead connections on the battery have become stripped form putting the cable on either too tight or crooked.

I suggest first getting two replacement bolts for your existing cables, and first try them in your new battery. Just try them to confirm the threads of the battery are ok. Don't screw them all the way in or you may damage the lead or the battery itself.

The good news is the battery likely was always the culprit. It is unable to hold a full charge. I always suggest a load test as the voltage will show a drastic and quick drop once the load is applied.

Keep us posted on what you find.
:cheers:
Marty

[Jetjock]

Side terminal batteries, at least in the US all use the same size bolt for the connection.

Side Terminal Battery Bolt 3/8-16 Thread

If your bolts are not tightening either the wrong bolts are in the battery cables, they somehow have corroded and are now wrong, or the lead connections on the battery have become stripped form putting the cable on either too tight or crooked.

I suggest first getting two replacement bolts for your existing cables, and first try them in your new battery. Just try them to confirm the threads of the battery are ok. Don't screw them all the way in or you may damage the lead or the battery itself.

The good news is the battery likely was always the culprit. It is unable to hold a full charge. I always suggest a load test as the voltage will show a drastic and quick drop once the load is applied.

Keep us posted on what you find.
:cheers:
Marty


One damn thing after another. I have the 3/8 bolt on the battery cable and the cables have not been stretched or damaged. The problem is that the AC Delco battery has the threads starting right at the top. This battery has the threads recessed inside the terminal connection. It's the right size
but doesn't start at the top of the terminal. I've looking for a slightly longer screw bolt but haven't found one yet.


Roy

[Jetjock]

After investigating the battery terminal bolt, I found out that the depth of the hole for the bolt is very tiny so I can't use a 3/4 inch bolt. Has to be 1/2 in length. The recessed part of the battery is about 1/8. The rubber on the cable extends out about an 1/8 inch as well. It's the rubber on the cable that is preventing contact withe battery. I'm trimming off the extra piece of rubber so that the bolt will make contact and screw on in.


Roy

[Jetjock]

Ok, problem solved. I trimmed the rubber off the battery cables and it worked! Put everything back together and cleaning up the garage. It started up great and no issues except for the right side door switch that says that it is open. Been dealing with for years. Anyway, that problem is fixed and now to the next one.


Roy