Pcm bad?

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i_burn_diesel

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Southern. IN
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1998
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12v 5.9
Hey guys I'm new to this forum, just recently traded my 2003 Chevy Silverado 2500HD 6.0 for a 1998 12v Dodge 5.9 Cummins Dually. I had problems in my Chevrolet (go figure) with the instrument panel going bad instrument motors not working. When I picked up this new truck I noticed none of the instrument panel worked at all, either. Speedometer, tachometer, fuel gauge, oil gauge, ect don't move at all. All of these warning lights are lit up on the dash, though. The alternator is fine but will not charge the batteries and I have tested the alternator to make sure it is fine and it is. So I set up an external regulator to charge the batteries and I've been looking around some forums and such but cannot get a definitive answer on whether it is the PCM or not. Thanks for any input on the matter.

-Logan


-Logan P
1998 5.9 12v long bed cummins
"farm truck"
Been shootin sh** since '96
i'm a Copenhagen cowboy
Born n' raised Southern IN
 
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i_burn_diesel

i_burn_diesel

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Any ideas


-Logan P
1998 5.9 Dodge Ram 3500
"farm truck"
Born n' raised Southern IN
 

rustydagger

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hemi 5.7 with K&N CAI and Diablosport Trinity Tuner
From what I understand on those trucks the voltage regulator is part of the pcm and in 90+% of cases if the alternator and batteries are for sure good it is the pcm.
Unless some wires are melted or chewed somewhere.

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rustydagger

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Have you taken it anywhere and had them read the obd codes?
Is the wiring tampered with much? There are several systems that people can and do bypass instead of replacing parts.

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Merc225hp

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Not my best area for these trucks but there is a fuse for all of that, no bus should be a code and I think the fuse is called oid or ord or oid ???? I will see if I can find it and post back.
 
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i_burn_diesel

i_burn_diesel

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Redtruck-VA I already have an external regulator installed and the batteries charge.


-Logan P
1998 5.9 Dodge Ram 3500
"farm truck"
Born n' raised Southern IN
 
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i_burn_diesel

i_burn_diesel

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I don't believe the wiring has been tampered with he told me he took it to dodge dealership and they said it was the pcm but I just wanted to double check before I shell out $400 to get a new pcm and it flashed


-Logan P
1998 5.9 Dodge Ram 3500
"farm truck"
Born n' raised Southern IN
 
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i_burn_diesel

i_burn_diesel

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Okay merc get back at me, I appreciate all the replies guys. Thanks for all the input loving the new #dodge pickup


-Logan P
1998 5.9 Dodge Ram 3500
"farm truck"
Born n' raised Southern IN
 

rustydagger

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What are your plans for this truck? It would be a good time to switch to a performance computer system or something like that lol

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rowdyram

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the inst. cluster is the ''mailbox'' for the pci bus system. it is very common to have these symptoms when the cluster fails. google a wiring diagram and check for power on the bus line to the cluster and or power on pin 4(i think) of obd 2 port. if power present replace cluster. no power replace pcm
 

Merc225hp

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Okay merc get back at me, I appreciate all the replies guys. Thanks for all the input loving the new #dodge pickup


-Logan P
1998 5.9 Dodge Ram 3500
"farm truck"
Born n' raised Southern IN

So the IOD fuse is found in the fuse box in the dash, might be spot 12 or 17. This might not be your problem but worth checking all the fuses. As I posted this is not my area of expertise for these trucks.
 
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i_burn_diesel

i_burn_diesel

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Thanks y'all. My plans is to just use it on the farm and to haul various equipment around. I checked the wires and they are all getting power so I am going to replace the pcm. Thanks guys!!


-Logan P
1998 5.9 Dodge Ram 3500
"farm truck"
Born n' raised Southern IN
 
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