Over charging problems
- Thread starter Ron Grubb
- Start date
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How and where are you measuring it.
When you say higher idle what do you mean?
14.5 is a good battery charging voltage. If it is 15 to 18 that's not so good to bad.
When you say higher idle what do you mean?
14.5 is a good battery charging voltage. If it is 15 to 18 that's not so good to bad.
67Dart273
Well-Known Member
14.5 is only borderline high. The "usual suspects are voltage drop in the harness, and sometimes, drop in the grounding. If the VR receives low voltage to it's IGN (power and sensing) terminal, it will bring the voltage up until that point is at the VR setpoint, 13.8--14.2. THIS MUST BE CHECKED with battery and VR warm and "normalized" IE charged back up after starting. Run engine at fast idle.
To check for harness drop, turn key to "run" with engine stopped. Stick a probe of your meter onto the IGN terminal of the VR (with everything connected normally) and the other probe into the top of the POS battery terminal. If you read more than .3V (3/10 of one volt) check out the circuit. The usual suspects in no order, are bulkhead connector, igntion switch connector, ignition switch itself, and sometimes, the ammeter
To check ground, run engine at high idle to simulate "low to medium" cruise RPM. Check first with all accessories off, and again with them on, headlights, radio, heater, etc
Stab one probe hard into the VR mounting flange and the other into the top of the NEG battery post. You should read almost nothing, and the lower the better, zero is perfect
To check for harness drop, turn key to "run" with engine stopped. Stick a probe of your meter onto the IGN terminal of the VR (with everything connected normally) and the other probe into the top of the POS battery terminal. If you read more than .3V (3/10 of one volt) check out the circuit. The usual suspects in no order, are bulkhead connector, igntion switch connector, ignition switch itself, and sometimes, the ammeter
To check ground, run engine at high idle to simulate "low to medium" cruise RPM. Check first with all accessories off, and again with them on, headlights, radio, heater, etc
Stab one probe hard into the VR mounting flange and the other into the top of the NEG battery post. You should read almost nothing, and the lower the better, zero is perfect
Every bad connection, bad ground, corroded connector, exposed copper wire, etc can cause resistance that can cause overcharging. Heck. I ruined a battery and blew my headlights out from overcharging simply because my regulator was loosely screwed to the firewall. Many guys have issues after painting their firewall because of poor grounds at the regulator or the ground strap between the block and firewall.
Have you tested your battery? A battery that has been over charged and is low on electrolyte can cause system overcharging.
14.5 at 1000 rpm is good
What is it at 2000 rpm?
What is it at 2000 rpm?
67Dart273
Well-Known Member
I WOULD NOT TRUST THAT!!! Check it AT the battery with a multimeter.
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