HUGE voltage drop issue....SOLVED?
#1
Thread Starter
Joined: Nov 2004
Posts: 27,563
Likes: 3
From: Maryland
Well, as some of you know, I have been fighting a voltage drop as I get near ~5000rpm. 13.6 volts down to 9volts. Crazy chit. I could go on for many pages of the things I have tried. I have been through 3 batteries and 3 alternators.
Well I never thought about an amp draw and therefore did an amp draw. There was an amp draw on the battery with key off for like a year and half. After pulling all fuses in the door panel the amp draw was down to .85 amp. YEAH! ALMOST AN AMP!!!! CRAZY!!!! I didn't pull the cigarette or radio fuses under the hood a s had my radio wiring completely disassembled.
There I sat in my truck with every freaking wire I had put in it unhooked on both ends, even the radio, all accessory fuses removed and I still had a freaking amp draw. Sigh. I actually hung my head in defeat. Seriously, hung it. Which as I was hanging it I couldn't help but notice my HPTuner's interface "busy" light was blinking ever so slowly. I was like...hmmmm. I unplugged it and the amp meter went to zero. WOW!!!!
Put truck back together, took it for a drive....works like a charm. Actually shifted when commanded now, obviously...its getting 13.9 volts...not 9 volts. But wtf?!?!!HPTuners interface is causing this?
So I started the process of emailing HPTuners support...(foff
) Long story short they felt it was something other than the interface. I had (have) to agree, electrically speaking, but I knew the interface was obviously involved in this weird mess, just not sure how it played the role.
I don't know how the pcm works with voltage dump, since the regulator is in my alternator, but I assume if the pcm was told there was too much voltage it could some how protect itself and dump voltage. On a dead battery this would prove to be a very ugly scenario. SO what I want, is a schematic of the OBD II pins. I want to know what happens when a particular pin is grounded.
About a year and half ago I kind of permanently put my interface in the truck. I have never taken it out. I only tune my truck, no need to really. Well, apparently the very last time I put it in a year and half ago I did the following.... LINKY <----clicky
Obviously when the interface is not plugged in the pin doesn't push against the grounded shield. Put the interface in and it pushes the pin against ground. I must know wtf that pin goes to or controls, if it is a hot wire why the F did it not short a fuse out.
Sorry for the long story, I have been battling this FOREVER!!!!
I am actually holding my breath that it is even fixed or gone away yet. LOL Thanks HPTuners for the fast emails!
Well I never thought about an amp draw and therefore did an amp draw. There was an amp draw on the battery with key off for like a year and half. After pulling all fuses in the door panel the amp draw was down to .85 amp. YEAH! ALMOST AN AMP!!!! CRAZY!!!! I didn't pull the cigarette or radio fuses under the hood a s had my radio wiring completely disassembled.
There I sat in my truck with every freaking wire I had put in it unhooked on both ends, even the radio, all accessory fuses removed and I still had a freaking amp draw. Sigh. I actually hung my head in defeat. Seriously, hung it. Which as I was hanging it I couldn't help but notice my HPTuner's interface "busy" light was blinking ever so slowly. I was like...hmmmm. I unplugged it and the amp meter went to zero. WOW!!!!
Put truck back together, took it for a drive....works like a charm. Actually shifted when commanded now, obviously...its getting 13.9 volts...not 9 volts. But wtf?!?!!HPTuners interface is causing this?
So I started the process of emailing HPTuners support...(foff
) Long story short they felt it was something other than the interface. I had (have) to agree, electrically speaking, but I knew the interface was obviously involved in this weird mess, just not sure how it played the role.I don't know how the pcm works with voltage dump, since the regulator is in my alternator, but I assume if the pcm was told there was too much voltage it could some how protect itself and dump voltage. On a dead battery this would prove to be a very ugly scenario. SO what I want, is a schematic of the OBD II pins. I want to know what happens when a particular pin is grounded.
About a year and half ago I kind of permanently put my interface in the truck. I have never taken it out. I only tune my truck, no need to really. Well, apparently the very last time I put it in a year and half ago I did the following.... LINKY <----clicky
Obviously when the interface is not plugged in the pin doesn't push against the grounded shield. Put the interface in and it pushes the pin against ground. I must know wtf that pin goes to or controls, if it is a hot wire why the F did it not short a fuse out.
Sorry for the long story, I have been battling this FOREVER!!!!
I am actually holding my breath that it is even fixed or gone away yet. LOL Thanks HPTuners for the fast emails!
#7
Thread Starter
Joined: Nov 2004
Posts: 27,563
Likes: 3
From: Maryland
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#9
Joined: Apr 2004
Posts: 16,820
Likes: 2
From: In a van DOWN BY THE RIVER





yeah I guess so huh?!!!!
Nah, my dumb ***...I guess "man handling" the interface is advised.