Voltage Drop

[jpellish]

Hi guys,
I was wondering if you could explain this to me.
In the day time without my headlights on and my amp disconnected, apon applying the brake a loose a half of a (.5) volt. Apon putting the turn signals on I loose another half volt. I was wondering if this is normal. My voltage always stays at 14.3-14.8, so sitting at a red light with the brake and turn signal on my voltage drops to 13.3-13.8 and stays there until i start moving. I just recently swapped the alternator to a 130amp out of a explorer and i have 2 optima yellow tops in the truck. Is this normal? Joe

 

[martin]

I would not be concerned, The alternator does not put out a lot juice at idle.

 

[jpellish]

Voltage Dropp

thanks,, i just took a ride and its dark so i used my headlights. the voltage drop is twice as bad as without headlights. it also does it while at crusing speed. i tested it while moving, revving the engine to 2500rpm and turning the turn signals on. still twice as bad. any ideas, bad ground mabye. i also know the alternator is good because i had it tested twice and it passed with flying colors. thanks -Joe

 

[Earl43P]

Investigate/clean grounds, check + cables for voltage drop.

Should have the same voltage at alternator post, B+ and UHJB +, assuming you can use a voltmeter. I also like to take voltage readings using other points as ground, B-, radiator support, engine, fender, frame. Would show you if a particular ground is bad.

http://www.therangerstation.com/tech_library/chargetroubleshooting.htm
http://www.therangerstation.com/tech_library/chargingsystem.htm


I've got the 2000 EVTM with Charging system schematic. PM me your e-mail address and I will fill your Inbox with what I've already got converted into .pdfs.
It's a lot, so clear your Inbox for tomorrow's deluge. I'd send them tonight, but they're on my work computer.


With those symptoms, I'd clean the small grounds on the fenders under the hood. Offhand, I don't recall which ground is for those lights, but it IS in the engine bay.

 

[jpellish]

thanks i will give it a try and see what turns out.
i will post updates on what i find tomorrow afternoon.
-Joe

 

[multiranger]

thanks i will give it a try and see what turns out.
i will post updates on what i find tomorrow afternoon.
-Joe

I have the same issue only when I turn on the blower motor on 3 or 4. drops a lot....

 

[jpellish]

Ground 103, Drivers Side Fender

This is located just behind the battery box towards the firewall. I tested it with a voltmeter and it read like 7V! I also tested every other ground possible and got 12V. Not too long ago I added another ground to that bolt to use with my AA-ROO-GA horn. lol. I guess that could have something to do with it, but it is very corroded as well. I will clean it and see what happens. Attached is a pic of it maybe one of you guys could verify it for me. Thanks -Joe

 

[jpellish]

unknown ground

this ground is on the passenger side fender, don't know what it goes too but it is really crappy as well. It has to do something reavelent so Im gonna redo this one too. -Joe

 

[jpellish]

re;mulitranger

have you had your battery checked? alternator? Are all of your battery cables/terminals, grounds clean and tight?

 

[multiranger]

have you had your battery checked? alternator? Are all of your battery cables/terminals, grounds clean and tight?

Yep. All tested out good.. (all is new but still tested)