You can type here any text you want

Help me figure out voltage drop problem please!

Welcome!

By registering with us, you'll be able to discuss, share and private message with other members of our community.

SignUp Now!
How do these things just pop up? On day fine and you do a few tweeks and bingo, your voltage drops when you hit the boost and car acts like it is stuck in low gear until turbo finally decides it wants to, kick in and then voltage really drops. I have a post running around on the issue to. If I solve the problem, I'll let you know. Sorry about your tranny. Hope I don't have that next.
 
Here is what we found on mine, we opened the hood and found the hose from the intercooler to the turbo had come loose where it goes on to the turbo, repositioned and reclamped. We pulled the cluster and checked all circuits, all looked good. We checked the connecting cable and found one broken ear and one ear just hanging on. We took inserted 2 rubber sticky back pads to keep the plug from moving back in to the plastic housing.

One of these two fixes worked and we no longer have a stumble and she runs fine.
 
finally have an update for this....I switched out the Altenator for a new 140 amp impala unit and reinstalled the bigger wire to the battery I had tried previously with the old alternator. I made a run and it only dropped to 12.8 volts. Still a little lower than I would like but at least my IDC is not maxed out anymore, it still hit 90% at one point. I am rich as all hell though on the A/F ratio so I think if I back off on the fuel demand the IDC will only max out in the 80's which is acceptable for now. I would still like higher volts at WOT but I dont know what else could improve it at this point, might look into a volt booster I guess.
 
short

I believe that you have an short or ground somewhere -- on good "clean"car you can see up to 14 to 14.2 volts at idle and should not drop under 13 at wide open throtle ..Hook up a volt meter to the alternator directly and run your car and see if the voltage drop is the same as your voltmeter in car ..?
 
I believe that you have an short or ground somewhere -- on good "clean"car you can see up to 14 to 14.2 volts at idle and should not drop under 13 at wide open throtle ..Hook up a volt meter to the alternator directly and run your car and see if the voltage drop is the same as your voltmeter in car ..?

What if the reading at the alternator is higher then what the scanmaster shows?
 
simple

then it gets a bit more complicated because you have just proven that your alternator is ok and the problem lies after it ..
 
my voltage at my ALDL port isn't what it is at the battery or altenator. It's just minor loss at the plug. If the connection gets too loose it could be .5 volts of difference.
 
I believe that you have an short or ground somewhere -- on good "clean"car you can see up to 14 to 14.2 volts at idle and should not drop under 13 at wide open throtle ..Hook up a volt meter to the alternator directly and run your car and see if the voltage drop is the same as your voltmeter in car ..?


Checked all the grounds and as much wiring as I could a long time ago, that was one of the first things I did. Plus the car has no other weird electrical things going on. Not saying that it might not still be a short or something but if I havent found it by now, I dont think I will. I'll try comparing the volts at the alternator with what it reads on the DS with this new alternator to see if it's different.
 
Bring This Post Back To Life

Need to revist this one as I am back having this same issue with the drop in volts at WOT, but this time used the voltmeter attached to the alternator and grounded inside the car. Bottom line is the voltmeter is reading 14+ at idle and 13.7 at WOT, scanmaster at all speeds reads lower, including idle reading drops to 11.4 or so at WOT and my VDO volt gauge is reading (best guess) 10.8 or so at WOT and 13 at idle.

What am I to make out of this? Is this then a not to worry issue?

My battery appears to be fully charged.

Thanks
 
step

Hey slick - just some food for thought .Since you have checked alternator and voltage is steady but not at the aldl now you can start back tracking sort of speak ..Orange wire #440 feeds the ecm thru a fusable link "j"..,you can put voltage meter directly on the wire and see what kind of voltage you have at idle and WOT and report back here.
 
Will check that out next week, have guest in from out of town this week, so am tied up.

Does it appear that the battery is getting charged and the my internal gauges and scan master are just reading wrong?

Thanks
 
i also am having a charging problem,charges 13.8 to 14.5 with no acc,s on as soon as you turn the a/c or the lights drops down to about 12.5.If you try to run both at the same time its at 11.5 volts.Tried a new alt and it wasnt better.I have also noticed the batt volts and the scanmaster volt readings are different,scanmasters about .2 lower than the batt is.
 
Back
Top