[AT] Off Topic. Need help with Dodge caravan computer maybe?

[Doug Tallman]

Cecil, There is a relay in the underhood box called an auto shutdown 
relay. It controls voltage to the ignition coil among a bunch of other 
circuits. you could check for voltage at the coil or just swap the relay 
with another similar one from the box and try it first. Doug T

On 5/19/2017 8:03 AM, Cecil Bearden wrote:
> St eve:
> Thanks I will try it.  My thoughts are that the charging syst em
> grounded through a sensor.
>
> Cecil
>
>
> On 5/18/2017 10:56 PM, Steve W. wrote:
>> Cecil Bearden wrote:
>>> I know a lot of you guys have more experience with the computer systems
>>> than I have.  I have suffered through Youtube videos of nearly every
>>> self described ëxpert"in diagnosing a no start condition.  Here's the
>>> timeline of what has been replaced and what happened.  Wife's 2003 Grand
>>> Caravan w/ 3.8L V6 130000 miles.  Sat Morning, alternator making loud
>>> whine heard 40 yds away.  Alternator would burn your fingers after
>>> running only 4 minutes.  Dropped Alternator and found noisy water pump
>>> also leaking when inspecting other pulleys.  Replaced alternator and
>>> water pump after bolt broke off on water pump.  Drilled it out Sat night
>>> with cordless screwdriver and hex chuck style bits.  Had partial threads
>>> so used a longer bolt and put a nut on back side.   Got it back together
>>> on Sunday and had to wait until Mon morning to get some Christmas tree
>>> fasteners to hold the belt shield.  Tuesday my wife drove it nearly 150
>>> miles in OKC and made at least 15 stops running errands with no
>>> problems.  Arrived at front gate and engine died.  Would not start when
>>> cranking.  It is possible she stopped and backed up when it died, ( just
>>> info for later )  but I cannot confirm.  Found battery ground cable
>>> loose after engine would not crank.  Tightened cable and cranked
>>> engine.  After several tries the starter would just spin and not engage
>>> the flywheel.   Wednesday got reman starter and spent 3 hours removing
>>> the old one.  I installed the new starter this morning, and it would
>>> crank but not start.  The new starter really grinds, sounds like it is
>>> coming apart.  Removed spark plug and cranked with spark plug
>>> grounded.   No spark.  Changed ignition coil and still no spark.
>>>
>>> I don't know where or how to start looking.  Since the battery cable was
>>> loose and I took off the ground to install the starter, the codes are
>>> not in the computer.  I don't find any method for testing the ECM.
>>> There are some forum discussions on the flex plate cracking around  the
>>> crankshaft in an octagon pattern and the flex plate shifting.  When this
>>> happens, the crank position sensor works on the flex plate, and is then
>>> out of time with the cam position sensor.   I cannot find an inspection
>>> plate to look at the flex plate.  It would be a 2 day job for me to
>>> remove the transmission to look at the plate.  However, I wonder about
>>> the original starter just spinning and then the replacement sounding
>>> like it is about to fly apart.  If the flex plate is not right, the old
>>> starter might have not been able to mesh and the new one is meshing but
>>> in a bind.  The old starter had to be pried out of the housing as the
>>> nose of the starter was nearly pressed into the bell housing.  The new
>>> one was easily pushed into the housing.   So far I have lost over 3 days
>>> and nearly $500 working on this when I need to be working on the swather
>>> and the water pump on the 1270 Case to pull the swather.  An ECM is
>>> another $400, and replacing the flex plate will be at least $600 because
>>> I need to send it out.
>>> Has anyone had any experience like this?   I know if I take it to the
>>> stealership, I will be out $1000 by the time they get done.  I don't
>>> have an independent mechanic here I can trust, and if I have to spend a
>>> bundle on this car, I am about ready to buy a new one and try to get a
>>> 20 year extended warranty!!!  Then maybe I can get some work done.
>>>
>>> Cecil in OKla
>> Grab a voltmeter. Turn on the key and test the crank sensor for power
>> and ground, It is on the bellhousing right below the crossover pipe for
>> the exhaust. 3 wires, Brown/Pink is 8 volt bias voltage, Dark Blue/Dark
>> Green is the ground. Brown/Light Blue is the signal wire. If you have a
>> scope you would see a square wave on that line.
>>
>> Easy cheat IF it has a tach, Does the tach move at all while cranking?
>>
>> Next, disconnect the battery. Hold the two cables together for about 30
>> seconds, this will drain the KAM capacitors. Now reconnect the cables.
>> Turn on the key and lock/unlock the doors twice.
>> See if it starts. You may need to step on the throttle if it acts like
>> it wants to start because it will need to relearn the TPS output again.
>>
>> csr684  at  yahoo  dot com  if you wish to continue.
>>
>
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