Quick GM alternator question
Moderator
Joined: Jan 2001
Posts: 56,999
Likes: 2,747
From: Virginia
The dash is wired different for the type of charging system you have. The signal to trigger your old system came from the "gen" light in the old dash. The old dash is gone, so you lost the light and the trigger wire that went with it.
Thread Starter
|
Logistics Pro
Joined: Aug 2003
Posts: 4,701
Likes: 6
I know it has been a month, but I finally got to go out for a few minutes and here's what I got. I ran the green w/red to run the white on the alternator. I pulled the connection apart, and tried the green w/red for power. With the key off there is no voltage. Key on, it measures the same as battery. That tells me that the white is, in fact, keyed on. Then, I measured amperage from the pos post to the pos cable. I had .3 with the key off. What does that mean? I have a slow leak somewhere, right? Next question is: how do I find it?
Senior User
Joined: Jan 2002
Posts: 377
Likes: 0
Originally Posted by teds74ford
Then, I measured amperage from the pos post to the pos cable. I had .3 with the key off. What does that mean? I have a slow leak somewhere, right? Next question is: how do I find it?
For example lets start at the starter relay, i would remove a wire from it. Then take one lead of the multimeter and connect it to the wire then the other lead and connect it to where the wire was connected on the start relay. This forces the power to go through the multimeter and it can measure how much there is flowing. Certain wires will have certain amounts, like the power going to the fuseblock that supplys power for the radio. YOu can also do this test on the fuse block by removing a fuse and forcing it through the multimeter. Beware that most multimeters can usaully only have a max of 20 amps load on them.
Thread Starter
|
Logistics Pro
Joined: Aug 2003
Posts: 4,701
Likes: 6
Originally Posted by 74F250
Your sure you measured amps and not volts? If so yes that is a draw somewhere. I always do the tried and true method of using the multimeter between connections on amperage. Some people do the ground side, i do the hot side.
Franklin, I can't use the test light method because I don't have a test light. I prefer the multimeter, but want to make sure I am not making a simple mistake when using it. Thanks again for the help, guys. Maybe one day I will find it.
Senior User
Joined: Jan 2002
Posts: 377
Likes: 0
Originally Posted by teds74ford
I guess what I am asking is, it should read exactly zero, right?
Originally Posted by teds74ford
Now, to narrow it down, you are saying try each circuit in the cab at the fuse block? Can't a rubbed wire that is hot cause a slow drain like this?
Also make sure your battery isn't the actual draw. I've had normal acid/lead plate batteries short across the top and cause a draw/drain on the battery. To check that take your multimeter and measure the voltage of the battery. Stick one of the leads on the + term and the other on the case of the battery in diff areas and see if you can get a reading of battery voltage. If so then the battery needs a good rinsing then repeat the voltage checking
Moderator
Joined: Jan 2001
Posts: 56,999
Likes: 2,747
From: Virginia
Originally Posted by teds74ford
I had it set to amps. I guess what I am asking is, it should read exactly zero, right? Now, to narrow it down, you are saying try each circuit in the cab at the fuse block? Can't a rubbed wire that is hot cause a slow drain like this?
Franklin, I can't use the test light method because I don't have a test light. I prefer the multimeter, but want to make sure I am not making a simple mistake when using it.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Thread Starter
|
Logistics Pro
Joined: Aug 2003
Posts: 4,701
Likes: 6
So, at 0.3, I am way over the 0.012 to 0.035. Any ideas what would take that much?
74, as far as the battery being bad, it is a couple months old. That being said, how do you mean to take a reading on a plastic case? I understand the pos terminal, just not the rest.
74, as far as the battery being bad, it is a couple months old. That being said, how do you mean to take a reading on a plastic case? I understand the pos terminal, just not the rest.
Senior User
Joined: Jan 2002
Posts: 377
Likes: 0
Just that, take a reading on the case. If the battery has leaked enough, even though you can't see it, the battery will transfer voltage across the battery case or whatever you want to call it. Like I was saying just stick one lead on the terminal, then take the other lead and jsut touch all over the top to see if you ever get any voltage reading.
Just curious but how fast is this draining the battery?
Just curious but how fast is this draining the battery?
Thread
Thread Starter
Forum
Replies
Last Post
carl2591
1999 - 2003 7.3L Power Stroke Diesel
7
Feb 27, 2017 08:59 AM
wyopokesfan
6.0L Power Stroke Diesel
5
Jun 16, 2009 04:03 PM
