Electrical issue
11-07-2017, 02:30 PM
#1
Registered User
Thread Starter
Join Date: Nov 2017
Location: Alaska
Posts: 10
Likes: 0
Received 0 Likes
on
0 Posts
Electrical issue
1990 Toyota Pickup 3.0
I'm Having an ongoing issue with my voltage dropping terribly while driving to the point of dying. I replaced the alternator with a new one and that didn't fix it. I just replaced the wire that runs from the fusible link to the battery and that didn't work. When I use my turn signals and power windows or even my headlights the battery gauge will drop. I've checked just about every ground I can see under the hood. Any other ideas would be greatly appreciated. Thanks!
I'm Having an ongoing issue with my voltage dropping terribly while driving to the point of dying. I replaced the alternator with a new one and that didn't fix it. I just replaced the wire that runs from the fusible link to the battery and that didn't work. When I use my turn signals and power windows or even my headlights the battery gauge will drop. I've checked just about every ground I can see under the hood. Any other ideas would be greatly appreciated. Thanks!
11-07-2017, 02:39 PM
#2
Registered User
How old is your battery? Do you know if the battery is good?
Are the battery terminals super clean and shiny (best electrical connections are made when clean, shiny metal touches clean, shiny metal)?
Are the battery terminals super clean and shiny (best electrical connections are made when clean, shiny metal touches clean, shiny metal)?
11-07-2017, 02:45 PM
#3
Registered User
Thread Starter
Join Date: Nov 2017
Location: Alaska
Posts: 10
Likes: 0
Received 0 Likes
on
0 Posts
Battery Terminals
I'm going to replace the terminals tonight and see if that helps. My buddy gave me a red top optima and it have 12.5 volts so I would assume that it is a good battery.
11-07-2017, 02:50 PM
#4
Registered User
Join Date: Sep 2007
Location: San Francisco East Bay
Posts: 8,254
Likes: 0
Received 822 Likes
on
649 Posts
An adequate battery, as long as it is charged, will hold up the voltage even with a dead alternator. So a voltage drop with headlights means the battery isn't charged, or isn't taking a charge.
This is easy to check. With engine off, measure the battery voltage at the terminals with your multimeter. Should be around 12.6v. Turn on the headlights. If the voltage drops below, oh, 12.3v then the battery isn't charged. Charge it, repeat. If it still drops, replace the battery (or take it to any parts store; they'll test it on their carbon-pile tester.)
If the battery holds up but you have a voltage drop at the voltmeter (or anywhere else) with headlights, use your multimeter to find the bad connection. Just keep measuring voltage to negative terminal as you move closer to the current draw. When you pass the bad connection, the voltage will start dropping.
This is easy to check. With engine off, measure the battery voltage at the terminals with your multimeter. Should be around 12.6v. Turn on the headlights. If the voltage drops below, oh, 12.3v then the battery isn't charged. Charge it, repeat. If it still drops, replace the battery (or take it to any parts store; they'll test it on their carbon-pile tester.)
If the battery holds up but you have a voltage drop at the voltmeter (or anywhere else) with headlights, use your multimeter to find the bad connection. Just keep measuring voltage to negative terminal as you move closer to the current draw. When you pass the bad connection, the voltage will start dropping.
11-07-2017, 02:52 PM
#5
Registered User
Join Date: Sep 2007
Location: San Francisco East Bay
Posts: 8,254
Likes: 0
Received 822 Likes
on
649 Posts
Trending Topics
11-07-2017, 05:59 PM
#8
+1 to getting a multi-meter, testing battery and making sure ALL connections are good. Repeat: ALL connections to alternator and battery, not just the cliched "check grounds".
Now, that's Yota brothers helping one another...^^^
Now, that's Yota brothers helping one another...^^^
11-17-2017, 03:55 PM
#12
Registered User
Thread Starter
Join Date: Nov 2017
Location: Alaska
Posts: 10
Likes: 0
Received 0 Likes
on
0 Posts
So the battery before starting was 12.8v
Started the truck- it went to 12.3v
turned on my hazards it bounced from 12.3v to 12.20v all in between.
Turned the lights on with the hazards still going and it dropped to 12.15v
sorry for taking so long to respond
Started the truck- it went to 12.3v
turned on my hazards it bounced from 12.3v to 12.20v all in between.
Turned the lights on with the hazards still going and it dropped to 12.15v
sorry for taking so long to respond
11-17-2017, 05:41 PM
#13
Registered User
what that tells me is your battery was fully charged, but your alternator isn't doing anything to keep it charged. check the connections from the alternator to the battery for power loss/bad connections. test the voltage at the alternator and see if it matches the reading at the battery when running. if not, fix the bad connection if so, check the circuits that energize the alternator, (sorry I don't have a wiring diagram maybe someone else can chime in here).
11-18-2017, 07:25 AM
#14
what that tells me is your battery was fully charged, but your alternator isn't doing anything to keep it charged. check the connections from the alternator to the battery for power loss/bad connections. test the voltage at the alternator and see if it matches the reading at the battery when running. if not, fix the bad connection if so, check the circuits that energize the alternator, (sorry I don't have a wiring diagram maybe someone else can chime in here).
This is for 22REliable, but wires leading to alt should be the same. "IG" is the "wire that energizes the alt"
https://www.yotatech.com/forums/f199...l#post52094780
11-18-2017, 05:14 PM
#16
Registered User
Join Date: Sep 2007
Location: San Francisco East Bay
Posts: 8,254
Likes: 0
Received 822 Likes
on
649 Posts
Absolutely.
Do you have a question?
AKWheeler had it right; your alternator is not charging. That's not AM1 or AM2 (which would take out a lot of other stuff, too.) Have you done the tests suggested?
Do you have a question?
AKWheeler had it right; your alternator is not charging. That's not AM1 or AM2 (which would take out a lot of other stuff, too.) Have you done the tests suggested?
11-18-2017, 05:22 PM
#17
Registered User
Thread Starter
Join Date: Nov 2017
Location: Alaska
Posts: 10
Likes: 0
Received 0 Likes
on
0 Posts
😐
So I went ahead and put a new alternator into it again and now it’s working like it should. I don’t know if maybe I forgot to connect something when I replaced it last time but she’s back to working condition. Thanks everyone for the help.
11-18-2017, 07:30 PM
#19
Glad you got it working
But you need to remember the suggestions above, in case it happens again.
But you need to remember the suggestions above, in case it happens again.
Last edited by RAD4Runner; 11-18-2017 at 08:32 PM.
Thread
Thread Starter
Forum
Replies
Last Post
BigRed-Runner
86-95 Trucks & 4Runners
0
04-14-2017 09:55 PM
Dylane2493
99+ Tundra, 00+ Sequoia, 98+ Land Cruiser/LX470
0
04-06-2017 06:20 PM
mrmike210
86-95 Trucks & 4Runners
12
03-31-2017 05:48 PM
