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I am getting a weird voltage issue on my 2009 Coupe.
The DIC and gauge show that my voltage is ranging between 9.9V and 12V never gets above 12.1V
I checked the alternator connection, the starter connections and battery and they all look good. removed them put some dielectric grease on them to prevent corrosion and put back together still the same issue.
Here is what is weird,
When i am getting 10V on the DIC when i check it at the battery with a multimeter i get 14V and it is a solid 14V. The car runs fine, my radio runs without an issue, i have never had a hard start, she fires right up everytime, i do not get a check engine light....
The only things i have noticed are
1. DIC and Gauge show low voltage
2. Traction control turns off and i get service traction control on the DIC
3. My HUD seems to be flickering, not sure if it did that before or not, cant say i ever looked that hard.
4. When i push the start butter there is a delay till the car starts (maybe 5 seconds), this has happened in the past didnt think much about it then and i dont think it has anything to do with the current voltage problem, it seems it is just trying to get fuel pressure up?.?.
In that case the readings are definitely too low if this is at idling with no a/c or rear defroster on - on the surface it sounds like your alternator might be on its way out - eventually it will start generating even less current and the voltage will drop further. You have not had a dead battery yet because the alternator is still generating some current and providing charging while running.
However, what surprises me is that you are not getting the service charging system message on the DIC.
You need to check the voltage of the battery in the ignition mode (engine off) and not ACC mode. Normal battery will be north of 11.8v.
Originally Posted by Hellbringer
I am sorry, this is all when the car is running, I will try it is acc mode and see if there is a difference
In that case the readings are definitely too low if this is at idling with no a/c or rear defroster on - on the surface it sounds like your alternator might be on its way out - eventually it will start generating even less current and the voltage will drop further. You have not had a dead battery yet because the alternator is still generating some current and providing charging while running.
However, what surprises me is that you are not getting the service charging system message on the DIC.
You need to check the voltage of the battery in the ignition mode (engine off) and not ACC mode. Normal battery will be north of 11.8v.
So, i did check it in ignition mode, and it is reading 9.9V when the engine off, but when i hit the start button again, no hesitation, fires right up
Originally Posted by DCasole;
Start checking grounds and check your starter selonoid.....
A bad solenoid or dirty ground will have these exact symptoms
I did check the solenoid, and cleaned the contacts, which here not corroded at all, there are no signs of heat at all, and i am still getting the same issue. I did not check the ground, i will check that tonight
I am thinking, this is the sensor is just reading it wrong, which i think the sensor is in the top of the alternator. My alternators housing is pretty corroded (electrical connections look fine) so it probably wouldn't hurt to replace it anyways which is, i think going to be my next step
If you are getting 14 volts at the battery your alternator is fine ...it has to be a ground issue , save your money , there is no sensor in the alternator
Dano is a great thread on chasing ground issues
If your alternator is cruddy that could be the problem , and what else was exposed to air and maybe salt corrosion
You could do a simple test , make sure your alternator mount and case is clean where it bolts to the bracket so you know you have a good ground. Then hook one end of a battery cable or suitable gauge wire to the bracket , hook the other end to the metal bracket under the steering column as I think that is a suitable ground , I will have to check . If it is, make sure the wire is not in the way of anything and start the car , read the DIC. If it reads a few tenths less than the alternator output , your problem is a ground ..
You could do a simple test , make sure your alternator mount and case is clean where it bolts to the bracket so you know you have a good ground. Then hook one end of a battery cable or suitable gauge wire to the bracket , hook the other end to the metal bracket under the steering column as I think that is a suitable ground , I will have to check . If it is, make sure the wire is not in the way of anything and start the car , read the DIC. If it reads a few tenths less than the alternator output , your problem is a ground ..
Dave
So... I have an update...
I am in agreement with you now that i have a ground issue somewhere. Today i was driving, and was driving a bit spirited, hit a bump and my gauge went to 13.9 volts and was good all the way to where i was going. Next drive got in was at 13+ volts within a mile or so started the low voltage, found a good bump in the road and she went right back up.
I looked for the post from Dano about finding a ground issue, but i cannot find it. do you know what the title was to make is easier to search
07-15-2017, 11:41 PM
Voltage Issue
