08 2.3 voltage spikes

[craveman85]

Have an 08 2.3 stick. My battery light started occasionally coming on with no ill symptoms. I tested my battery myself at 12.6 volts even after it sat for a day. Cranking drops it to 10.5 when it was 15° out which is still in spec for a good battery. Most of the time charging it's around 14.6 when I start it then drops to 14.0-14.3 volts. Then on my way to work the other day the lights got really bright, the heater blower started really pushing air, the battery light came on and my passenger airbag off light started turning on and off. Had my battery load tested at a parts store and it's fine. Only a year old anyways. My alternator also tested fine. I was going to buy a new alternator originally because I couldn't find a voltage regulator for it and thought it was inside the alternator. The parts guy told me that the ranger voltage regulator is in the ecm. That would explain the light going off too. There's no check engine light on. I hand a scangauge 2 for monitoring things but I can also check for codes. It says no codes found/not ready. Like you disconnected the battery and need to drive it. However this was before my battery was tested and hasn't been disconnected for about 12000 miles before that. After i had it tested I did go through and clean all battery connections I could find and also added 2 more ground wires just in case. I did have one day where I didn't have enough juice to crank the engine over and that was the day of my voltage spikes. Every time I check my battery it's at 12.6ish with a multi meter.
The parts guy told me dodge people have the same issue and bypass the built in ecm regulator and use an old style voltage regulator. Have any of you guys done this? A general how to would be great. I'm not sure if I want to get a new ecm and have it re flashed at a dealership. But if I could make the regulator work I could continue my 80 mile daily commutes until my inspection runs out next year and I decide what to do. It's a good truck but it's got 180k on it. Needs a steering rack, rear springs and shocks, lower control arm bushings, fuel pump because the check valve in it is bad...

 

[RonD]

Ford's Smart Charging is designed to be used with silver calcium batteries, not regular lead acid type batteries.
Many have used lead acid and reported no problems, but it isn't universal, so...........

Most common issue with these systems is the wiring, more specifically the wiring from alternator in the engine bay, check it carefully.
Disconnect the 3 wire connector on the alternator, and follow the loom looking for damage, usually from heat.


Alternators are still basically the same
In the case of the alternator are 3 "Fields", coils of wires
The rotor also has coils of wires, the rotor is given 7 to 9 volts DC by the voltage regulator which creates a magnetic field around the rotor, like an electro-magnet.
When the rotor spins this rotating magnetic field creates AC voltage in the 3 Field Coils
The mechanical energy from the spinning increases the 7 to 9 volts DC to 13-15volts AC in the 3 Field coils
Each Field has a set of Diodes that change AC Volts to DC Volts.

Voltage regulator adjusts the rotor's 7 to 9 volts to increase or decrease the Output voltage of the alternator
Prior to Smart Charging this was done just by the voltage regulator based on battery voltage.
Smart Charging also monitors battery voltage but shortens the higher Recharge voltage(14.6+) which can give the battery a longer life

Voltage regular shouldn't be able to give rotor more than 9 volts, but that can happen causing a voltage spike, above 15 volts
Diodes can start to fail and leak AC into the DC system which will also cause a voltage spike.

An alternator can test OK but still be failing

To test Smart charging feedback from computer you need to test it with an oscilloscope, which most DIYers don't have, but you can test the system, vs replacing parts on spec

 

[craveman85]

Maybe my lead battery is confusing it then. It's currently -7 and charging at 15 volts. Never knew about the silver battery. Have a part number for those? Auto zone knew nothing of what I was talking about. But most of those guys there are McDonald's employees that couldn't operate a spatula.

 

[craveman85]

I checked with a ford dealership. The only part numbers they had were for lead acid batteries. The guy was confused when I bought it up. All the Google ford ranger smart charge or non lead acid battery results I got were from Australian websites... are you giving me Australian info?

 

[RonD]

Ford has them for $100, 7 year warranty

The difference is minimal, smart charging increases the voltage to recharge when battery is cold, this can "boil away" lead acid type batteries faster, so shorten their normally 5 year life.

I would check your wires first

I think Ford dealers can change smart charge software for lead acid type use

 

[craveman85]

Is it possible that my alternator could produce enough voltage but maybe not enough amps? When I first start it I'm getting 14.8-15 volts still but my battery light may be on. I switched out the battery for the ford one and noticed no difference. I did resistance tests on the main wires so they're still good.

 

[craveman85]

Problem continues. Highest voltage spike I've seen lately is 16.3 volts. My headlights flicker sometimes. Not completely off but between dim and bright. Heater blower motor changes speed as well as the battery light and passenger airbag light flickering on and off. The voltage rarely spikes right now. Usually 14-14.6. I feel like if I was starting to lose power at the alternator and battery it would make the truck run differently and my voltage reading doesn't change every time the lights flicker. Maybe the interior fuse panel? Where is battery voltage read for the indicator light? From the computer or off the panel?

 

[craveman85]

Finally got bad enough to get it on film this morning. I'm going to get an alternator when the parts stores open. If that doesn't work I'll just keep going from there.

 

[craveman85]

https://youtu.be/cEt07bnBM6k

 

[adsm08]

I have dealt with these systems extensively. They are a pain in the butt.

The alternator does still have a regulator on it, but it isn't as independent as the old ones were, it needs cues from the computer to do its job. I have never once seen the PCM go bad and cause a charging system issue thought. The only failures I have ever seen were the alternator, or the gencom line, which is the wire between the PCM and alternator.