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98 12 valve cummins no bus, need help please


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15 minutes ago, Great work! said:

I re- read your first post and saw you had a tap on a fuse. Double check that fuse position sometimes those taps spread out the prongs or melt back into the plastic. Use a small pick and make sure the prongs have a good grip on the fuse.

I definitely will check that ive pulled the tap out and set just a fuse in it and didnt notice a change it powers the color lighting for my guages on the tap they all work fine but definitely possible 

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3 hours ago, Mopar1973Man said:

2.49 and 2.51 respectively after all communication is done.

Did some probing i have ABS,PCM,CTM modules un hooked i pulled fuses for airbag as well instead of unhooking module under dash cause i didnt want to fight with it. Radio left connected for now. I have 2.55/2.57 reading with multimeter set to 20v DC pin number 28 & 31 C3 PCM witch is CCD -/+. Grounds read good, power is good to PCM. I do not have 5 volt reference signal not sure it that’s important, ABS 2.53/2.56 and grounds test good. I cant get a reading on the ctm yet or  data link but if they test good what would be next step 

Edited by KyleM94
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Those readings seem reasonable. I think you mean pin 30 not 31. All you need is the PCM and cluster plugged in and some of the guages should work. Check the voltages by back probing or piercing the wires too with it all plugged in too. Just one place is enough.  Check for 12 volts at the cluster  C1 pin 2 and 6 and verify good grounds on pins 4 and 5.

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2 hours ago, Great work! said:

Those readings seem reasonable. I think you mean pin 30 not 31. All you need is the PCM and cluster plugged in and some of the guages should work. Check the voltages by back probing or piercing the wires too with it all plugged in too. Just one place is enough.  Check for 12 volts at the cluster  C1 pin 2 and 6 and verify good grounds on pins 4 and 5.

Good readings at all 4 pins

Edited by KyleM94
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On your wiring diagram look for the things labeled joint connector. The CCD bus ties together there. try reseating the plugs and use some contact cleaner. There's a group up past the E brake , clutch area. Also more strip looking things in the PDC spray them and wiggle a bit with a toothpick or something.  I don't recommend you try prying them out.

Edit note there are joint connections for the airbag system. Leave those alone.

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16 hours ago, Great work! said:

On your wiring diagram look for the things labeled joint connector. The CCD bus ties together there. try reseating the plugs and use some contact cleaner. There's a group up past the E brake , clutch area. Also more strip looking things in the PDC spray them and wiggle a bit with a toothpick or something.  I don't recommend you try prying them out.

Edit note there are joint connections for the airbag system. Leave those alone.

Wiggled around the connectors and pressed them together to make sure i sprayed the PDC ones with some contact cleaner. Without pulling the dash i cant get to the others to spray them but i did find something interesting. I cant get any reading on fuse 1 in the dash junction block. It just says infinite its a 20a max size fuse. I pulled it out the connection isnt broken but it has what appears to be corrosion inside of the fuse i will include a picture could this be the culpritIMG_1134.jpeg.6c71113ddb621cabc62e5773a63f455d.jpeg

Edited by KyleM94
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Luckily I found a dash out in the wild. My diagram has some errors on it and apparently there are more. The locations are swapped on the diagram. The joint connector you want is directly above the hood release you might have to remove the knee panel and hood release lever.

 

The joint connector above the column and below the cluster is air bag related. Fortunately Dodge made the dash out of fragile plastic so it can be broken away under the cluster for access.

 

Looks like fuse 1 is for the marker lights and part of the dimmer circuit.

20240224_134426.jpg.6c20ab747686ba31c2cfa961e87981dd.jpg

20240224_134426.jpg

20240224_134403.jpg

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1 hour ago, Great work! said:

Luckily I found a dash out in the wild. My diagram has some errors on it and apparently there are more. The locations are swapped on the diagram. The joint connector you want is directly above the hood release you might have to remove the knee panel and hood release lever.

 

The joint connector above the column and below the cluster is air bag related. Fortunately Dodge made the dash out of fragile plastic so it can be broken away under the cluster for access.

 

Looks like fuse 1 is for the marker lights and part of the dimmer circuit.

20240224_134426.jpg.6c20ab747686ba31c2cfa961e87981dd.jpg

20240224_134426.jpg

20240224_134403.jpg

Thats a perfect picture i have the knee panel pulled id like to not destroy my dash but if it fixes my problem then ill sacrifice some of it. Ill get them pulled sprayed and seated. I want to err on the side of skepticism so assuming this doesnt work then any other diagnostic to do?

 

 

edit pulled them sprayed with cleaner and re seated them 

Edited by KyleM94
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Frustrated? Ready to home run that B? For that you need about 10 ft of light duty speaker wire. Cut the Ccd wires wht/blk and vio/brw an inch or so from the PCM plug and wire the speaker wire to the plug and note the polarity. Likewise at the cluster cut the CCD wires and wire the speaker wire to the cluster plug.  Double check the polarity. Leave the ccd wires in the harness hanging for now. No need to do any fancy splicing just temporary for now. If that doesn't do it then you got bigger problems.  If it works then try tapping in the CCD wires from the harness to the speaker wire one end at a time and see what happens. 

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8 minutes ago, Great work! said:

Frustrated? Ready to home run that B? For that you need about 10 ft of light duty speaker wire. Cut the Ccd wires wht/blk and vio/brw an inch or so from the PCM plug and wire the speaker wire to the plug and note the polarity. Likewise at the cluster cut the CCD wires and wire the speaker wire to the cluster plug.  Double check the polarity. Leave the ccd wires in the harness hanging for now. No need to do any fancy splicing just temporary for now. If that doesn't do it then you got bigger problems.  If it works then try tapping in the CCD wires from the harness to the speaker wire one end at a time and see what happens. 

So pretty much a straight splice from PCM to cluster. What do you mean by note polarity

Edited by KyleM94
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1 hour ago, Great work! said:

Are you sure your PCM is powered up.

C1 pin 2 lt grn/ blk  12 key on

C1 pin 22 red/WHT 12 v always.

C1 31 and 32 grounded.

Another sign of life is battery charging 14 v or more at the bat when running.

Yes but i will recheck in the morning i have an external regulator on it right now since when this started it stopped charging but my voltmeter shows batteries fully charged when running

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Im having some late night thoughts looking at the FSM looking at the circuits for the wait to start and for overdrive light. Now if im understanding this correctly and thats a big IF, the power for the circuit goes from

Battery A7  -> Fuse 14 -> WTS 

Battery A7 -> Fuse 14 -> OD indicator 

 

Now fuse 14 is the fuse i have a tap in that is the same fuse tap that blew (coincidence maybe)

 

For the second half of the circuit then it would be 
 

WTS/OD light -> PCM 

 

So in this circuit the PCM is providing ground? 
if so the problem may be here how would i test the circuit at the fuse and at the pcm to make sure is functioning as it should?

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  • Owner

PCM controls the Overdrive light. 

 

ECM controls Wait To Start light. This is the only light that the ECM is in direct control of that is wired directly to the light.

 

P0381 code would be present if there is no circuit or light issue for the Wait To Start.

 

Only way to test either ECM and PCM is to send the modules to @Auto Computer Specialist and let them bench test the modules for you.

 

Look at pin 37 is Wait To Start. 

image.png

 

Look at C2 pin 14 which is the Overdrive switch 

image.png

 

Cluster wiring... You can see the O/D switch.

image.png

 

Orange/black pin 8 is your wait to stat from the ECM.

image.png

Edited by Mopar1973Man
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54 minutes ago, Mopar1973Man said:

light.

Except i don have an ECM and im 99% sure this PCM is good i got it from a reputable local dealer that does all of PDDs PCM/ECM

21 minutes ago, Great work! said:

Those square fuses in the PDC can go bad and not look blown. You should check them with a meter or substitute. 

 

PCM has to have ground though the black/ tan wires. The bolts and ground strap is not enough. 

Ground strap? Mine just bolts in but i have 12.4 volts on the ground pins when checking ground

Screenshot_1.jpeg.747139e7397bf0f869dfae944e05340a.jpeg

 

this is my wiring for WTS everything goes to PDC in engine bay then to PCM since its a 12 valve i do not have a ECM. Its just odd that the one fuse i had the tap blow on is also shared between both lights that are on when the key is turned to run im wondering if its just coincidence 

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