93 Caravan Speedo/tach problem. Help?

Hi.

I need to pick some brains regarding an odd intermittent problem.

I have a 1993 Dodge Grand Caravan SE with a 3.3 L engine. Everything
works excellently except for the speedometer and tachometer "freezing"
at random intervals. On a perfectly smooth road [no bumps appear to be
a trigger] the speedo and tach will both stop right in their tracks
and stay stuck at whatever speed/rpm I was traveling at the moment,
even if I speed up or come to a complete stop. The odometer will also
stop dead too. The other gauges appear to keep working fine. If I stop
then shut the key off, the speedo and tach will then drop to 0. Upon
an immediate restart, they usually will remain at 0 no matter what I
do. Then, while driving for a few minutes, they will suddenly start
working just fine. At that point the power door locks will realize
that I am moving and will lock the doors, as they are supposed to.
Sometimes, the speedo/tach will "freeze" for a few minutes then
suddenly start working as I am driving, without me stopping or
shutting off the key.

This does not happen often but often enough to be a concern, about
once or twice a week. Today, however, it happened twice within a 15
minute span. Hitting any bumps in the road makes no difference one way
or another.

I would really like to fix this problem, as the van is in almost mint
condition otherwise and I would live to keep it for a while.

Any help would be greatly appreciated.

--

(Jim, single dad to Lesleigh [Autistic] 04/20/94)

"What, Me Worry?" A. E. Newman

Please note: All unsolicited e-mail sent to me may, at
my discretion, be posted in this newsgroup verbatim.

 

Sounds like a loose connector or a bad ground somewhere. Two places to look
right off check the battery cables (yes I know it sounds to simple but.....)
and check the cable ground at the engine bleck too.
Larry

 

I see you have a 10 year old Caravan and you say no problems other than this
small speedometer problem, no tranny problems etc.. It is great to hear this
, I just bought a 2003 GC with 3.3 and love it. Of course it is new, my
friends and mechanic say I made a poor choice due to the reliability of the
past. I hope your Van is an indication that they are good and hopefully
after 10 years there even better. Good luck

 

I think they are great little vans. The guy I bough it from sold it
because he had just bought a brand new Caravan. Couldn't be THAT bad
if he bought another one. My dad put over 300,000 kms on his 1994
Caravan before it was totaled in an accident. The transaxle was
replaced under warranty at 76,000 kms then the van was absolutely
trouble free after that. My '93 has only 152,000 kms on it.

If they are so bad, as your friends say, than ask them why Chrysler
sold so many millions of them. History has proven that truly bad cars
will not sell. Look at the Chevy Vega and the Ford Pinto for just two
examples.

My speedo/tach glitch hasn't happened again since my first post.
Perhaps the ghost of Walter P. decided to watch over me ;-)

--

(Jim, single dad to Lesleigh [Autistic] 04/20/94)

"What, Me Worry?" A. E. Newman

Please note: All unsolicited e-mail sent to me may, at
my discretion, be posted in this newsgroup verbatim.

 

Tried poking around at the grounds under the hood. Since the problem
is so intermittent I really can't be sure if I did anything at all.
The bad ground idea makes sense.

--

(Jim, single dad to Lesleigh [Autistic] 04/20/94)

"What, Me Worry?" A. E. Newman

Please note: All unsolicited e-mail sent to me may, at
my discretion, be posted in this newsgroup verbatim.

 

I have the same problem in My 1992 Dodge Daytona with the Tach, on
rare occassion the same with the speedometer.

Let me know if you find the problem.

 

Any suggestions I hear I will post right here. I imagine they may use
the same body and power train computers, with different software.
--

(Jim, single dad to Lesleigh [Autistic] 04/20/94)

"What, Me Worry?" A. E. Newman

Please note: All unsolicited e-mail sent to me may, at
my discretion, be posted in this newsgroup verbatim.

 

You can check around for the chrysler FAQs; I think ALLPAR's site has
them. I authored the fix for this, and if you can solder, you can fix
this yourself. Basically the instrument cluster's Printed Circuit
Board (or PCB) uses pressed in 'revits' to connect the top and bottom
copper traces on the PCB. Flowing solder over ALL of these revits
fixes the problem 99% of the time. If you can't solder, you can still
save money by pulling the instrument cluster yourself, and find a
local speedo repair shop to re-flow the PCB for you. Some will do this
for a good price.

Now, in your case (the power door lock are throwing me off), you could
also have a connection issue with your 'body computer'. I would get a
can of TV Tuner cleaner, and spray clean all of the MOLEX connectors
on the body computer harness and the harness to the cluster's PCB as a
starting point.

Keep us posted on the symptoms.

Bill

 

I just re-read your original post; I suppose it is possible that you
have two causes to one symptom?

The speedo sounds like a speed sensor, and/or it's connection going
out.

The tach sounds like the PCB 'revits' need a solder re-flow.

A possible failure that would cause the multi symptoms is a lack of 5
volts at the cluster, which could be a component, connection, GND,
solder joint, etc, etc.

If it were mine, I'd reflow the cluster's PCB, then tuner spray clean
every MOLEX connector between the body computer and the cluster.

Good Luck!

 

An interesting observation lately. Since I posted my first message,
the tach and speedo have behaved flawlessly, not one hiccup. It should
be noted that it has also gotten colder around here lately. [I live in
Edmonton, Alberta]

I wonder if there is a connection.

--

(Jim, single dad to Lesleigh [Autistic] 04/20/94)

"What, Me Worry?" A. E. Newman

Please note: All unsolicited e-mail sent to me may, at
my discretion, be posted in this newsgroup verbatim.