Overcharging 68Dart...need some short fused help (pun intended:)
Thanks for checking in Dana, I appreciate it!
Well, I missed my 24 hr deadline
But, I no longer believe I have a problem with my charging circuit/components, and I'm changing my focus to the load. Also, after reading the instruction sheet included with the VR, I found that it said that the VR may smoke for the first 30 minutes while it burns off the coating that held the coils in place during transit. Read the instructions, right?!
Here's where I am now:
Yesterday I ran a dedicated 12GA wire from the alternator to the fan relay circuit breaker to remove it from the battery charging line as Mattax suggested.
I replaced the 14GA wire that I had run in parallel with the charge line from the alt to the ammeter with 12GA wire just to be on the safer side.
After pulling back all the tape and loom on the wire harness I found that there was no fusible link on the line from the starter relay to the ammeter, and I also found that the PO had hacked in wiring to bypass the melted terminal on the bulkhead connector. I replaced the original wire from ammeter to the starter relay with a 12GA wire through a 30A fuse (it's what I had on hand).
I ran a new 16GA wire from the VR to the alternator field and reconnected the wires to either side of the ammeter in the instrument cluster so I could monitor charge/discharge.
I pulled the VR and checked that nothing did or could contact the resistors on the bottom of the VR.
I also put the battery on the charger for an hour or so to make sure it was topped off.
On startup, everything looked great, battery voltage at idle and throttle looked normal (12.9 to 14VDC). With no accessories on and no cooling fan (it kicks on at ~180F) I noticed that the ammeter showed about a needle’s width toward charge. When applying throttle, it moved up a bit, but settled back to original needles width.
Took her for a drive and found that after a few minutes of driving, the voltage gauge would read high ~14-17VDC, and the ammeter was at the line between center and full charge and would raise lower with RPM. Idling at a stop sign, it would return to center and voltage would drop to about 13-14 VDC. (this is with the cooling fan still not on....it's about 50 degrees here in WA).
Fast forward about 2-3 minutes, and about a 1/4 mile from home, the 30 amp fuse I installed blew. A short walk later (with a new fuse) I limped home and called it a night. I’m pretty sure that I fried the cheap aftermarket radio with the high voltage, and I hope that’s all!
I believe I have something pulling excessive current through the ammeter circuit. I'm going to pick up an 30A ammeter gauge tomorrow, build a test box for it, and start isolating the circuit (divide and conquer) to see what's pulling all the amps.
Since current draw (and battery voltage) increases with engine RPM, do you think it could be something in the coil/distributor circuit?
I've spent today licking my wounds, beer helps ;) And I have a new 3 week deadline (good to have goals:) Son would love to drive the Dart to school before he graduates HS.
Thanks again for reaching back out to me, I REALLY appreciate your help!!
-Corey
Thanks for checking in Dana, I appreciate it!
Well, I missed my 24 hr deadline
But, I no longer believe I have a problem with my charging circuit/components, and I'm changing my focus to the load. Also, after reading the instruction sheet included with the VR, I found that it said that the VR may smoke for the first 30 minutes while it burns off the coating that held the coils in place during transit. Read the instructions, right?!
Here's where I am now:
Yesterday I ran a dedicated 12GA wire from the alternator to the fan relay circuit breaker to remove it from the battery charging line as Mattax suggested.
I replaced the 14GA wire that I had run in parallel with the charge line from the alt to the ammeter with 12GA wire just to be on the safer side.
After pulling back all the tape and loom on the wire harness I found that there was no fusible link on the line from the starter relay to the ammeter, and I also found that the PO had hacked in wiring to bypass the melted terminal on the bulkhead connector. I replaced the original wire from ammeter to the starter relay with a 12GA wire through a 30A fuse (it's what I had on hand).
I ran a new 16GA wire from the VR to the alternator field and reconnected the wires to either side of the ammeter in the instrument cluster so I could monitor charge/discharge.
I pulled the VR and checked that nothing did or could contact the resistors on the bottom of the VR.
I also put the battery on the charger for an hour or so to make sure it was topped off.
On startup, everything looked great, battery voltage at idle and throttle looked normal (12.9 to 14VDC). With no accessories on and no cooling fan (it kicks on at ~180F) I noticed that the ammeter showed about a needle’s width toward charge. When applying throttle, it moved up a bit, but settled back to original needles width.
Took her for a drive and found that after a few minutes of driving, the voltage gauge would read high ~14-17VDC, and the ammeter was at the line between center and full charge and would raise lower with RPM. Idling at a stop sign, it would return to center and voltage would drop to about 13-14 VDC. (this is with the cooling fan still not on....it's about 50 degrees here in WA).
Fast forward about 2-3 minutes, and about a 1/4 mile from home, the 30 amp fuse I installed blew. A short walk later (with a new fuse) I limped home and called it a night. I’m pretty sure that I fried the cheap aftermarket radio with the high voltage, and I hope that’s all!
I believe I have something pulling excessive current through the ammeter circuit. I'm going to pick up an 30A ammeter gauge tomorrow, build a test box for it, and start isolating the circuit (divide and conquer) to see what's pulling all the amps.
Since current draw (and battery voltage) increases with engine RPM, do you think it could be something in the coil/distributor circuit?
I've spent today licking my wounds, beer helps ;) And I have a new 3 week deadline (good to have goals:) Son would love to drive the Dart to school before he graduates HS.
Thanks again for reaching back out to me, I REALLY appreciate your help!!
-Corey
