Jump to content

evil electrical issue need some serious back up


Recommended Posts

Ok so to start this started in the winter. When i first fire my truck up my voltage bounces from 13 to are 6 till the engine warms up then it would start charging like normal after 5 to 10 mins. No big deal i started it let it run before i go to work. Now that it is warming up. I start it and if i touch the pedal and bring in even little bit above ideal the voltage drops to around 6 and stay there. Until i let the rpms drop. Then it will bounce around then most times come back to normal. Long story short put a alternator two weeks ago and a computer on the fire wall. I have had it to the stealership twice and they always come up with something retarded that they think it might be. I the codes i keep throwing are tpps low voltage, turbo solenoid low voltage, and one other low voltage code. i can go month with it fine and i can go a day. The worse part of it is it makes a dead spot in my pedal. I have replaced the tpps because of dead pedal in the past. But this is different the charging system is shuts down randomly and taking voltage away dropping it below 12 volt for no reason. I have been looking around and all i can come up with is the battery battery temperature sensor. Which from what i understand tells the system to charge. My question is what does the cam position sensor do and can it affect the charging system never have touch it in over 300k. Also last trip to to dealership they flashed everything with the newest updates and the problem was there before and after they flashed it.

Link to comment
Share on other sites

The crank sensor is what controls charging, if the pcm does not see the proper signal from it there will be no charge. Does your tach bounce around erratically? That could possibly be an indication of a bad crank sensor also. The low voltage codes are most likely a result of your no charging situation, I'm sure your aware of that.

Link to comment
Share on other sites

  • Administrator

Ummm... I need you to do some more testing. * Load test the batteries (removed from the truck)* Load test the alternator (removed from the truck)There is no way to drop to 6V and keep the truck running. The minimum voltage required is 8 volts and then the truck will die. So I need you to verify with a DVM or analog volt meter that the battery voltage is actually falling off. You might check ground and positive feed lines into and out of the PDC (power distribution center) verify the power is actually reaching the ECM and PCM as 12 volts. Even with my alternator unhooked I still hold ~12 volts without a alternator.

Link to comment
Share on other sites

I took it to a electrical shop today had them go through everything. When i got there the system was bounce between 11.2 and 14.4. The battery are new and alternator. The pcm is less then six months old and has the latest updates thank to my wonderful local dodge dealer to broke the plug off the front. The shop took my engine harness out and pulled it part all of it looked good. I called cummins nw also they are telling me to start with the cam sensor also. Then if the issue no fixed with the sensor. I guess ill be taking a trip to Spokane to cummins to have them figure it out. The cam sensor has never been replaced by me. I bought the truck with 70k and now I'm a little over 300k

Link to comment
Share on other sites

  • Administrator

The battery are new and alternator. The pcm is less then six months old

Just because these are new doesn't mean they are working correctly. Might read this post as another member found out just because you got a NEW alternator doesn't mean it working correctly. http://forum.mopar1973man.com/threads/5937-Torque-Converter-Lock-Unlock-Issues?p=63884#post63884
Link to comment
Share on other sites

yeah it is 1998.5 and i did have the alternator tested and i had the electrical shop check the computer to make sure it is working correctly. My main issue is this it hard to track down because it is random it seem to happen the most when it gets above 70 or so. Last week it was in the 90's and i started it and it would turn the check light on even before the drove it. Funny part is when it is running like that it is like having my programmer on crazy man mode. It fuels so hard that cant see the highway behind me for a quarter mile when i am trying to merge. Maybe i wont fix it kind fun truthfully. Tomorrow my cam sensor should be here so i will put it in am hope for the best. Ill let you all know. Give me a reason to put in my steer shaft and gear box in also.

Link to comment
Share on other sites

  • 4 weeks later...

Update on my fun for the month. Ok got my Cam sensor in took about 20 mins no big deal. Cleared the codes with a scan tool drove it about day no problems. Then it go above 80 and here come the same issue. But now i'm still get little different codes. My voltage is still dropping for no reason. Here is the code let see what you all think. I have a feeling my pcm is a bad and the voltage regulator took a crap in it. My other one made it almost 300k and this one is only 7 months.

P0121 Accelerator Position Sensor (APPS) Signal Voltage Too Low

P0122 Accelerator Position Sensor (APPS) LowAPPS Voltage Input Too Low

P1689 No Communication Between ECM & Injection Pump Module

P1693 Generic fault indicating a fault in the bus or PCM/ECM interface

- - - Updated - - -

Update on my fun for the month. Ok got my Cam sensor in took about 20 mins no big deal. Cleared the codes with a scan tool drove it about day no problems. Then it go above 80 and here come the same issue. But now i'm still get little different codes. My voltage is still dropping for no reason. Here is the code let see what you all think. I have a feeling my pcm is a bad and the voltage regulator took a crap in it. My other one made it almost 300k and this one is only 7 months.

P0121 Accelerator Position Sensor (APPS) Signal Voltage Too Low

P0122 Accelerator Position Sensor (APPS) LowAPPS Voltage Input Too Low

P1689 No Communication Between ECM & Injection Pump Module

P1693 Generic fault indicating a fault in the bus or PCM/ECM interface

Link to comment
Share on other sites

  • Board Of Directors

I had a similar issue, it turns out that I was backfeeding back into the power system through a poorly installed AirDog solenoid that was essentially acting like a transformer. I was able to eliminate the alternator & voltage regulator, as I pulled the alternator field wire and it still showed a spike in voltage across the battery terminals. The only real suggestion I have from my experience, is to try to think about what changes in your electrical or mechanical/electrical system when you see the issues. As in my case, it could be something totally unrelated, but causing mayhem with the sensors by putting too much power through the system.

Link to comment
Share on other sites

You know it all seem to start after i put my HID lights in I had the battier box out on the drivers side. and i installed a 6 fuse block the i am powering of the power post in the fuse panel under the hood i wounder if it is heating up and sending crazy power to all the main fuels

- - - Updated - - -

Ok thank you CSM for your advice. Just spent all morning with my tester. Long story short my cam sensor was toast had broke the plug off with a fir limb. So that set of code is fixed. Them here came the electrical issue with it. I put my HID lights in in the fall. Well just happen that its about the time heat grid started being used do to temp. Today found one of the fusible link is cooked and the relay on the finder is back feeding into the electrical system. It was dragging the system down for just s second at a time. Which was shutting down my apps and my fuel timing and putting my truck into lump mod. Just got back from a 50 mile drive most was on dirt roads and charging system ran great no issues. Final thing i figured out heater grid was coming on a sticking at random even when hot. That way when it getting warm like in the 80 and 90 the relay was heating and back feeding and sticking. Taking out my charging system. So need to get a new relay and feed line coming off the battery. But for now unplugged it no power to it so no issue. Note for everyone when you start have a load against your charging system you and you cant figure it out. Cummins NW told me that the grind is pulling around 95 amps and 12v. So always start there. Fine death toll to fix this was Alternator, PCM, Cam Sensor and 2 trips to dealership, Cummins NW and Local Guy. Funny thing is I got more information from everyone on here then the trip to repairs shops. Thank you everyone

Link to comment
Share on other sites

×
×
  • Create New...