98 Grand Caravan: Blinking dash lights... again.

Hi all,
I've read all the old articles on the problem of blinking HVAC dash
lights. They all seem to be battery related. I haven't had the
battery changed or removed, but I have had some... weirdness. ABS
light comes on, then others, then the instrument panels go off and on
erratically. This hasn't happened in a month or so.

I ran through the tests (hold buttons, etc.) and when it finishes, the
A/C and Recirc buttons remain blinking steadily now. Can anyone tell
me how to stop those or does it mean a real problem? I prefer a fix I
can do by myself since I just got layed off and paying a dealer will
hurt more than ever. Thanks for any help.


Ed Payne

 

::shrugs:: I wish I could say for certain any of the posts relating
to our dash problem were solved - we could never get it to happen on
demand for the dealer to see exactly what was happening. The only
unusual thing is that it *hasn't* happened since the last reset of
error codes.

Which of course means that I haven't checked the grounds yet since
it's working fine now apparently. If it does it again, I'll probably
clean 'em, but right now I've got enough problems keeping another car
going on its last legs. Good luck.

- D

 

A friend of mine just had this happen on his '98 voyager. It seems to
be associated with the fact that he had let his battery go dead. The
flashing probably means that some computer memory module has to be
reset. I'll ask him what he did about it when I see him next.

 

it may be the ingition switch is failing causing a loss of power to the
hvac head during crank mode and corrioded battery terminals can cause this
too

 

This is very interesting as I had somewhat of the same problem a couple of
year back. It happened to me because I had accidentally pressed two of the
HVAC buttons at the same time. This starts either the Diagnostics test or
the Cooldown test. Either one requires the AC system to be working properly
and efficiently. If the AC can not cool the system in less than the
specified time, the test will fail, or if there is another failure in the
system, the test will exit and flash failure codes on the HVAC lights, by
setting various combinations of lights. My AC charge was low, and could not
cool fast enough to meet the test. I had a failure code flashing. The
interesting thing was that you are suppose to be able to abort the test,
manually, or the test will abort after 15 minutes. Or one would also assume
that the test would abort if you turned off the power (key off). But on
mine, as I suspect yours is doing, the flashing lights always returned, or
flashed forever.

I seem to recall my determination was that if it gets into the test far
enough to set a code, it will continue to flash the code forever. (I'm not
sure if this is what it is suppose to do though). My fix was (besides
getting an AC recharge to get the tests to pass) was to restart the tests,
one by one, and then abort immediately before it could rest the failure
codes. It might be worth another try if you haven't already tried it in the
exact sequence as below.

Try this.
-Van running
-Blower to Hi
-Mode selection to Panel
-Temp control(s) to Cold
-Press and Hold simultaneously WASH and AC for about 5 seconds until all
LEDs light up.

AC and RECIRC light flash alternately when test starts running.
If they flash together - cooldown has failed (This is where you are stuck)
If the lights change to alternately flash WIPE and INTERMITTENT then the
test has progressed to Calibration. Simultaneously flash is test fail. All 4
flashing together is both tests fail.
If the it changes to WIPER only flashing - this is all tests pass. At this
point pressing WIPER should exit the test mode.

To try and abort as soon as the test starts (AC and RECIRC flashing
alternately). Press REAR DEFOG, RECIRC and REAR WIPE together (before they
change to simultaneous flashing). Turn ignition off and wait > 15 minutes
with key off. Failing this, run through it again, but when you get to Key
off for 15 minutes, go out and disconnect the battery as well and wait 15
minutes. If this does not cure the problem then you do have another
electrical problem related to your other symptoms. However, you are
definitely getting an AC cooldown failure, so your other problem might
somehow be triggering the AC test to start by setting power on the WASH and
AC lines simultaneously.

You real fix is to get the AC system serviced (could also be a leak). Likely
the charge is low.

Good luck.

 

Hi guys,
Thanks for all the info. Unfortunately, things have gotten worse... I
think. I was driving for about 20 minutes one time and noticed that
the button lights were acting normally. They still do their dance
every time I crank the van again.

New things are happening now, though. I went to crank the van and got
nothing... no interior lights, no starter click, etc. Just like a
dead battery. I had the battery checked and it is a very healthy
battery: good charge under load, good water level, etc. It's only a
year old. Eventually, things come alive again and I can crank it.
The instrument panels seem to be going wacko quite often now. I HATE
ELECTRICAL PROBLEMS. And this from an electrical engineer. ;^) I
never had any of these problems until they replaced the rack and
pinion at the end of August. It sure does act like there is a
computer problem, but I'm sure I could never prove that they did
anything wrong. Believe it or not I trust my dealer somewhat. They
looked at the previous problem for 3-4 hours one time and didn't
charge me a thing because they couldn't find anything. I know that
once the swap-and-try method comes into play, I could still lose a
bundle because it's just replacing parts until the problem goes away.
Since it's intermittent, this could take a while (and a lot of $).

Rudy, let me know if you get any information from your friend. Enough
anecdotal info just might give me the wisdom to solve this problem.
Thanks, guys.


Ed Payne