2z?

I have a 2000 C5 with about 67 thousand miles and as my car is getting older, I've developed some quirks with my electronics. Could they all possibly be related? I'm trying to figure out where to start with all this (maybe a new alternator pulley/belt and replace the BCU?). The car is an California and Arizona vehicle. Battery was recently checked to be OK and the car never has trouble starting.

1) when the car is on, there is a whine coming from around the engine (seems like from the alternator) that gets louder as the RPMs go higher. It honestly sounds like a supercharger (I wish) and is exacerbated when the a/c is on. It also sounds like there is a "stretching" or winding noise from behind the stereo but before the engine after the car is warmed up with the a/c turned on. The whining from the engine cannot be heard with the windows up but the stretching/winding noise can be heard from the cabin.

2) if I open my door widely, at certain angles, the electronics to my door shut off. I can tell they shut off because the lights on the window/lock buttons go away.

3) the passenger lumbar controls have stopped working. Sometimes while driving, unprovoked, the seat will go crazy and try to go backwards and forwards with no one in the seat at all.

4) at times, I am completely unable to control the passenger side a/c. The driver's side will be blowing ice cold air but I cannot get the passenger side to do anything but blow hot air--pisses off the lady quite a bit during our AZ summers.

5) I am using a GM10 Aux module connected from the disc changer cable harness in the trunk box. At some point during every outing, the sound from the driver's side of the car goes very quiet. This doesn't ever happen with the CD or radio. Also, inputs with GM10 Aux are much quieter than the radio or CD.

6) for some reason (most recent issue), both flip-up headlights come up automatically when I try to ONLY turn them on halfway (as in I only turn the lights **** one notch as to not turn on the headlights at all). The actual headlight bulbs are off when this happens. I now have to kind of turn the **** between the 1st and 2nd setting to avoid this.

7) (possibly related to 6 because it started at the same time) Every time when I try to lower my flip-up lights, the passenger side flip-up will try to go down even further than it can and I can hear the motor of the headlight from inside the car for an additional 4 or 5 seconds trying to force it down. It makes me nervous that it will snap or something.

8) the horn doesn't work when I lock the car with my remote (I suppose this is a bad horn relay) but it does work when I press in the steering wheel.

Here are the codes I'm throwing:

[BCM] - B0502H, B2482H, B2527HC, B2583H, B2721H, B2723H, U1255, U1016H, U1096H
[A0-LDCM] - U1064H
[A1-RDCM] - U1255H, U1069H, U1016H, U1096H
[B0-RFA] - U1096H, U1064H, U1016H, C2110H

Any thoughts on where to begin tackling this mess? I'm ready to fix and replace.

2z?

Here are some of the threads I've read through using search--learned a lot but I'm hoping for a starting point so I'm not merely fixing symptoms of a bigger issue.

http://forums.corvetteforum.com/c5-t...ut-i-dont.html
http://forums.corvetteforum.com/c5-t...ing-noise.html
http://forums.corvetteforum.com/c5-t...ompressor.html
http://forums.corvetteforum.com/c5-t...s-running.html
http://forums.corvetteforum.com/c5-t...t-working.html

WKMCD

I had a diode go bad in another verhicle and it caused a odd wine from the alternator. The is also a notorius connection in the drivers side door accordian that is prone to develop corrosion. At this age, it's a good idea to check all the grounds on car and clean them up.

Corvette_Ed

Welcome to my world. Be prepared to get your hands dirty and spend a good amount of your time tracking down root causes. You might want to look into replacing/repairing certain parts as you go, such as the ignition switch, so you don't have to tear the same areas apart multiple times. Good luck!

2z?

Thank you both for your responses. I think I'm going to start by having the alternator checked out and well as the BCU. I'm also going to have them check some of the notorious ground connectors for corrosion. I think the headlight issue is definitely the notorious stripped gear issue--hopefully that's not too much of a PITA to repair with a brass one.

Harry Bilgewater

I have had to regear both of my Headlamp motors due to the failure
of the plastic drive gear used. The motor shaft has a worm gear
which drives the conventional gear made of plastic. Repeated
thermal cycles and exposure causes the plastic to become brittle
and the gear will crack. In my case a few of the cogs fell off and
the continued running after reaching a full down position on one
and a full up position on the other. The right side eventually went
spin crazy and I had to disconnect the motor to stop it from running.
I ordered the brass replacement gear for both. I had to literally split
the ultrasonic plastic weld used to bond the plastic housing parts
on the motor assembly. Use a Dremel cutting disc to cut gaps
along the bonding line, then insert a screwdriver in the cut slots
and twist to break the remaining welded portions apart. If you cut
all the way around then it can be difficult to get the correct fit
when re-assembling. Also buy a small metal drill bit and bore holes
through the plastic along the bond lines at a diagonal through the
housing before splitting the case. When re-assembling this allows
you to use safety wire to hold the two pieces together while the
epoxy used in re-assembly properly cures.

Check the settings on the "Options" to determine if the "Horn
when locking" is turned off. Lots of neat features are hidden
from direct view that are not overtly obvious with using treed
menus.

Do you hear the alternator whine with the radio off? I would
replace the serpentine belt first. Look at the ribs on the belt.
If there are any fractures in the ribbed rubber then it may very
well be a noise maker. While the belt may only have 68,000
miles on it the materials used degrade with exposure to the
elements (air - ozone specifically) and thermal cycling of the
integral Kevlar material. Inspect the pulleys that the belt runs
on for signs of dings in the grooves. One other problem I have
had is the idler pulleys have bearings which can make some
wierd sounds when they are at end of life.

If you hear the alternator whine only with the radio turned on
then you may have a bad diode as mentioned by another writer.
There are actually six diodes in the alternator but they are potted
in a single assembly. When one goes bad you may not notice as
during regular running it will keep the battery charged. It will
be noticealble however often when idling as the charge voltage
will like drop below the normal levels you observed when the car
was new. The alternator produces AC voltage, which is rectified
by the diodes. This results in a pulsating DC voltage which is
filtered by the battery. (The battery not only stores starting
power but is a big fat electrolytic filter capacitor). When one
diode goes bad or one of the three phases drop out this causes
a problem with the regulated voltage. It often is noticeable in
the car radio audio when the volume is turned down. If you lose
two diodes the voltage pulses and can vary enough that the
computers will start balking due their DC Power not being a
consistent voltage or dropping momentarily under the minimum
operational voltage. Computer logic hardware can be very
unpredictable when the supply voltage is not clean, has pulses,
varies in voltage or has additional impulses superimposed on it.

Check your battery voltage after the car has set for a few hours
before starting the car. It should show a minimum of 12.6 VDC. If
it is below that level then I would try another battery. The battery
has six individual cells internally, each producing 2.1 Volts when
fully charged. ie 6 X 2.1 volts = 12.6 volts. When they start to be
a problem one cell or more will not produce the correct voltage
after setting for an extended period. While the charging system
indicates all is well the one cell with problems is not converting
the chemistry as expected to replenish the acid to a normal state.
The remaining five cells overcharge and produce a slightly higher
voltage for a short time until the good cells balance out. This
hides the bad cell right after turning the engine off. It is more
noticeable also when the weather is colder.

Hope this helps with some of your problems.

Harry

WICKEDFRC

1) Have you tried to isolate the whine with a mechanics stethescope? My whine sound (like yours, like a supercharger) was a failing pump. Power steering or oil pump. I forgot which one. The pump that went bad was driver side, front area, down low. If you use the mechanics stethescope, you will find and isolate the whine.



2) The doors are supposed to have lights in the electronic swicthes? Holy crap. I never knew that. Great. Now you got me needing to look into something myself. If the lights go on and off, I suspect a kinked wire in the door jam path. Sometimes my window will not roll up or down and I simply open my door all the way and whalah.....The window goes up. Its got to be the wiring in the door jam.

3) Sounds spooky. Suggest an exorcism.

4) passenger side AC teeth in the vents may be jammed or worn. A royal PITA to fix. Try to disconnect battery and reset. If that don't work, pull AC/HVAC fuses for 2 minutes (60 seconds, but 2 minutes will not fail you) and reinstall fuse. Allow car to go through diagnostic self checks. Also, did you reset all codes?





8) Scroll through the DIC for manual set up and see if HORN is set to honk YES

Here are the codes I'm throwing: RESET ALL CODES and then see if they all match again in a few days.

[BCM] - B0502H, B2482H, B2527HC, B2583H, B2721H, B2723H, U1255, U1016H, U1096H
[A0-LDCM] - U1064H
[A1-RDCM] - U1255H, U1069H, U1016H, U1096H
[B0-RFA] - U1096H, U1064H, U1016H, C2110H

Bill Curlee

The door issue can be fixed by popping out the rubber accordion tubes between BOTH doors. Pull the door harness connectors up and out of the hole in the door A pillar where the accordion tube connects.

Disconnect the wiring harness connectors and carefully examine the FEMALE PINS in the connectors. Some of them will be bent and spread apart.
That causes them to make POOR contact with the male pin. You can use a metal pick and bend them back so they make good contact.

Do BOTH doors as this is a very common issue. This problem can get bad enough that it can cause sever serial data buss issues and some strange IPC symptoms!!

Bill

Bill Curlee

If you get board and want to bond with your car, here is something else you should do:

- C5 ignition Switch repair - http://forums.corvetteforum.com/c5-t...ch-repair.html

WICKEDFRC

What the heck.....We should add on the Hazard Relay Switch removal as well.