Alternator/Battery Charging issues
- Thread starter Waterproof
- Start date
1. Remove, scrape & clean the battery posts & clamps, 'til they shine. While disconnected from each other.. you should see 12+ volts*.. from EACH batt.
2. Flex the cables, if they crackle, or the sheiding cracks.. scale falls out, replace'm. Check the wires & connections, to, and at the Starter.
3. Look around, all under the hood for ground wires. Back'm off'n re-tighten. Look for the obvious too.
4. At the Alternator* main lead, engine running, you should see..14+ volts.
* Batteries can be Bad.. off the shelf. Be sure you have quality Batts, of the right Group and CCA's. Reman alternators have been known to be Bad.. out'a the box.
Joe
DaveBen
SDD Senior Member
Zmann has a good idea with the Diodes. When they go bad they will put a drain on the power lead to the alternator. Pull off the power wire from the alternator and then touch it to the post and see if you see a spark of any type, big or small. If you do, then your alternator has a bad diode or two.
Dave
Dave
Waterproof
SDD Junior Member
Update to the issue. Okay had the batteries on the charger to charge back up this week. They tested good, which I am not suprised considering they are only about 10 days old.
Cleaned the holy hell out of my battery clamps, terminals, alternator connector ring. Brushed them all up nice and shiny, double checked all of my connections around the battery terminals and cables.
Disconnected the alternator wire from the battery terminal and metered the voltage with the truck running. Showed ~9 volts at the battery terminal ring and matching voltage at the back of the alternator. Tells me the fuses are good and the alternator is not putting out enough voltage again.
Took it back to Advance Auto parts and it tested bad on their testing station also. So they swapped out that 2 week old alternator for another one, tested good before I left the store.
Put the now third replacement alternator in my truck. I left the wire from the alternator to the battery disconnected at the battery so I could meter the voltage on this alternator. Started up the truck and at first it didn't show any voltage, then it went to around 9 volts again.
When I am doing my metering, I am not going to the negative terminal of the battery, but am actually going to steel in my engine compartment to make sure there isn't a grounding issue from my battery terminals.
What can I meter or check to see if I am having some module problem or a voltage reference problem? What else can I possibly try to get this issue fixed?
Cleaned the holy hell out of my battery clamps, terminals, alternator connector ring. Brushed them all up nice and shiny, double checked all of my connections around the battery terminals and cables.
Disconnected the alternator wire from the battery terminal and metered the voltage with the truck running. Showed ~9 volts at the battery terminal ring and matching voltage at the back of the alternator. Tells me the fuses are good and the alternator is not putting out enough voltage again.
Took it back to Advance Auto parts and it tested bad on their testing station also. So they swapped out that 2 week old alternator for another one, tested good before I left the store.
Put the now third replacement alternator in my truck. I left the wire from the alternator to the battery disconnected at the battery so I could meter the voltage on this alternator. Started up the truck and at first it didn't show any voltage, then it went to around 9 volts again.
When I am doing my metering, I am not going to the negative terminal of the battery, but am actually going to steel in my engine compartment to make sure there isn't a grounding issue from my battery terminals.
What can I meter or check to see if I am having some module problem or a voltage reference problem? What else can I possibly try to get this issue fixed?
DaveBen
SDD Senior Member
Start off by checking the voltage at the alternator WITHOUT the engine running. It should be very close to Battery voltage (12v). Now start the engine and monitor the voltage. It should go up to about 14v and remain there until the battery if fully charged. Then is should decrease down to 12.8 v. Good Luck!
Dave
Dave
Waterproof
SDD Junior Member
It doesn't do that. I explained below my voltage readings I had from this.
Waterproof
SDD Junior Member
Additional update and request for more information.
Talked to a Ford Service tech and he wasn't super helpful other then he wanted me to bring the truck in so he could run diagnostics on it and charge me over a $100 just for that.
However he did say to see if the battery light came on when I turned the key to run before I started it, and if that light never came on then the alternator could not ever charge the batteries.
Tested that part and my light does not come on, which I have since found out means that the regulator plug at the back of my alternator is not getting the required 12VDC switched voltage to excite the alternator and cause it to send out the charging voltage.
Now the fun part, I know the regulator plug (which I have already replaced once) leaves the alternator and about 4" later goes into a wiring harness, what is the best way to trace that wire back to the battery light in my instrument cluster and see where the breakdown in continuity is occuring?
I looked through the Haynes Motor manual as well as my owners manual and there doesn't appear to be any fuses involved with this, nor can how I can trace this wire out from the instrument cluster to the regulator plug.
Talked to a Ford Service tech and he wasn't super helpful other then he wanted me to bring the truck in so he could run diagnostics on it and charge me over a $100 just for that.
However he did say to see if the battery light came on when I turned the key to run before I started it, and if that light never came on then the alternator could not ever charge the batteries.
Tested that part and my light does not come on, which I have since found out means that the regulator plug at the back of my alternator is not getting the required 12VDC switched voltage to excite the alternator and cause it to send out the charging voltage.
Now the fun part, I know the regulator plug (which I have already replaced once) leaves the alternator and about 4" later goes into a wiring harness, what is the best way to trace that wire back to the battery light in my instrument cluster and see where the breakdown in continuity is occuring?
I looked through the Haynes Motor manual as well as my owners manual and there doesn't appear to be any fuses involved with this, nor can how I can trace this wire out from the instrument cluster to the regulator plug.
Zmann ARGH
Full Access Member
That actually sounds very helpfull ? mine does come on
DaveBen
SDD Senior Member
It is a fused link for the regulator. I don't know where it goes, but would suspect the ignition.
Dave
Dave
