Alternator pulling battery draw

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Carbajal73

Junior Member
Joined
Apr 5, 2025
Posts
5
Reaction score
1
Location
Sierra Vista Az
First Name
John
Truck Year
1986
Truck Model
K10
Engine Size
454
I have a draw 2.5amp when I disconnect regulator from alternator it goes away. So I got a new alternator and same thing. Any help
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
10,083
Reaction score
7,399
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
I have a draw 2.5amp when I disconnect regulator from alternator it goes away. So I got a new alternator and same thing. Any help
play with the key switch and see what it does , like every position
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
6,288
Reaction score
10,676
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
I have a draw 2.5amp when I disconnect regulator from alternator it goes away. So I got a new alternator and same thing. Any help
Make sure terminal 1 and terminal 2 aren't flipped. When you say disconnected the regulator I'm assuming you mean the 2 wire plug on the alternator. Terminal 1 should only have power key on engine off,terminal 2 is 12v constant.
 
Last edited:

Carbajal73

Junior Member
Joined
Apr 5, 2025
Posts
5
Reaction score
1
Location
Sierra Vista Az
First Name
John
Truck Year
1986
Truck Model
K10
Engine Size
454
Okay yeah that's what I thought I didn't been looking for a wiring diagram for the bulkhead coming out of the firewall because my stepson bought this truck originally came with a 5.7 and somebody put a 454 in it but nothing's hooked up and I believe that alternator wire is jumped over to the feedwire and that's why it's causing the draw
 

Carbajal73

Junior Member
Joined
Apr 5, 2025
Posts
5
Reaction score
1
Location
Sierra Vista Az
First Name
John
Truck Year
1986
Truck Model
K10
Engine Size
454
Make sure terminal 1 and terminal 2 aren't flipped. When you say disconnected the regulator I'm assuming you mean the 2 wire plug on the alternator. Terminal 1 should only have power key on engine off,terminal 2 is 12v constant.
Yeah that's what I thought but I need really need is the wiring diagram color for the bulkhead
 

Carbajal73

Junior Member
Joined
Apr 5, 2025
Posts
5
Reaction score
1
Location
Sierra Vista Az
First Name
John
Truck Year
1986
Truck Model
K10
Engine Size
454
Yeah that's what I thought but I need really need is the wiring diagram color for the bulkhead
play with the key switch and see what it does , like every position
Yeah thank you for the information I can replace it alternator too but it's still there but I think the wiring is wrong
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
6,288
Reaction score
10,676
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
Is terminal 1 only hot key on engine off? And terminal 2 constant 12v hot? If so the wiring is correct.
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
10,083
Reaction score
7,399
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
You must be registered for see images attach
You must be registered for see images attach
 

Forum statistics

Threads
45,428
Posts
983,158
Members
38,458
Latest member
Bigman240
Top