desired_speeds

I was driving home from the supermarket today and I got the battery voltage screen and the convenience functions disabled message. I continued on my way home and while waiting at a stop light comand threw a message saying comand will shut off in 3 minutes please start engine. I turned off the main road and I got the battery message, stop car! brake message. i turned off the car and it wouldn't start again because the battery is dead. The tow truck driver came, put on a jumper pack and I was able to drive it onto the tow truck. I get it towed home, and it decides to start. any ideas? I've already ordered a remanufactured alternator, just in case.

Hasan Shaikh

It is most probably the altenator.

The regulator might have gone with it.

desired_speeds

Since the car started and put out a consistent 14.2V after i got it towed home, I decided to go for a drive around the neighborhood with the voltage display. it stayed between 14-14.2V when I started driving around, but as the car heated up the voltage started dropping to 12.6V so I decided to drive home before I had to get it towed again. On the way home it dropped to 11.9V and stayed the same until I got home. I noticed that when the SBC pump cycled, it would drop to 11.5V. I get home and let it idle on my driveway and it was stay at around 11.9V and sometimes spike back up to 14.2V or 13.8V for a short time then drop back to 11.9V. I also noticed that when it would spike to 14.2 for a few seconds and I give it a rev, it would drop the voltage to 11.9V.


any ideas? I have an alternator on order and I was going to try the voltage regulator to see if it solves the problem. If not, then I'll try the whole alternator.

desired_speeds

I really hope that will solve the problem. Best to replace both then. This car has only given me electrical problems so far.

Hasan Shaikh

If you can get the fault codes scanned, it will tell you whether its the altenator or the regulator. Its better than guesstimation.

turbovan

I reckon its probably the regulator, mine had similar symptoms and replacing the reg fixed it

lowprofile

I would replace both depending on mileage. It seems like a regulator issue if you wanted to repair it on a budget.

BBBSS

I'm gonna throw my guess at the regulator as well. Contacts are probably worn down. How many miles on it?

desired_speeds

yea, I'll try to get it scanned.

I've already ordered the alternator, but I'm really not interested in ripping out the fan sand everything to pull it out. I'll swap the regulator over first and give it a shot.

124k mi. already. fingers crossed its the regulator!

vettdvr

it could be battery with interanl short

novae500

Get a multimeter and test both batteries to see the voltage.

desired_speeds

changed the voltage regulator and drove it around. seemed to sit fairly steady at 13.8V and 13.7 with load. It would occasionally dip to the lower 13 range when I brake because of the SBC pump. is 13.8V normal for driving around?

jt2ma71

If you have an AVR tester you can full field test the altenator and rule out the voltage regulator. All it does is control current through the rotor. If it goes you may have low charging voltage output.

The reasoning for the AVR tester on a full field is to load the battery to prevent 16v + spikes from going through the system. Jump the regulator depending on style, if voltage spikes up then you know its the voltage regulator if it stays the same its internal in the altenator.

jt2ma71

Generally between 13.2-14.5V with no load at 2000rpm in neutral.