I just ordered a BB Grounding Kit for the G and decided to create a controlled experiment, of sorts. Before I install the kit, I have set my radar detector (Escort 9500ix) to display vehicle voltage as a primary display (i.e., 100% of the time unless there is an alert). Here's the weird part:

1) Upon start, the vehicle seems to select a voltage, either 13 or 14 VDC
2) After it selects this voltage, it does vary as you would expect, +/- .5VDC depending upon accessories on or speed
3) If it starts at ~13VDC, it never exceeds ~13.5VDC
4) If it starts at ~14VDC, it never exceeds ~14.5VDC

Neither of the above conditions (3 or 4) are impacted by turning on the stereo or air conditoining. In fact, I would expect the vehicle to sit around 14VDC until I turn something on and this is not the case... it really doesn't seem to matter what I turn on in the vehicle, the voltage will not vary from the initial start up voltage. There seems to be no rhyme or reason for the vehicle to select starting at 13 or 14VDC, as each start has the same accessories on / same condition as the prior stop, but yet the voltage may be different! Additionally, it does NOT recover over lengthy drives, it will remain +/- .5VDC of the initial starting voltage, sometimes 13VDC and sometimes 14VDC.

Anyone else have similar experiences?

Lee

 

That's odd to me too. The voltage regulator in modern cars keeps it from spiking or dipping with most normal electrical loads. If you had a couple thousand watts of stereo amplifiers you would most likely see it dip at musical peaks, but other than that it shouldn't. However the part about it starting at either 13 or 14 volts randomly is strange to me. You haven't been able to determine what the X factor is between the two starting voltages? How accurate and precise do you think the voltage readout iof your radar detector is?

BTW, your Grounding Wires are being shipped out tonight. I'd love to see what the difference is electrically.

 

No idea what the trigger is yet... but I do believe the voltage meter is pretty accurate. Will keep you posted.

L

PS: Anyone else with this issue?

 

Test the Escort ranging capability by hooking it up to a variable DC power supply. Current limit the power supply to about an amp.

Start at 12 volts with the Escort in voltage mode.

Run the voltage up to just over 15 V. The fuse should protect the Escort but don't go much over 15V just in case.

Note how the Escort tracks the voltage. It might give you very coarse readings like you're seeing, 13.0, 13.5, 14.0, 14.5, etc.

I'd be surprised if the grounding kit affects the readings.

The Escort volt meter is most likely an "indication only" device, not a precision meter. I would expect a voltage of around 14.8 VDC with the vehicle running unless, like BB says, you've got something installed in the car that really loads the system.

Interesting experiment, though. If you really want a detailed picture of how the electrical system is performing, use an oscilloscope. Doesn't have to be a fancy one.

If I get truly motivated, I'll take my scope out to the car for curiosity's sake. Vehicle electrical systems, if working properly, are very stable but a bit noisy sometimes. I'd expect the grounding kit to help with the noise.

Too late for me to contribute much, my kit is already installed.

Kahn - principal software engineer, vehicle automated diagnostics systems.

 

Yeah - the measurement doesn't seem very coarse, .2VDC in any direction seems to be the minimum change. I watched the car go from 14.8VDC down to 13.4VDC with NOTHING ON in the car (no air, no radio, no lights, etc.) in approximately 60 seconds... it then stayed there for the remainder of the drive... I am concerned that I may have a regulator issue.

Lee

 

Actually, that sounds normal. I think your charging system is ok.

Maybe I mis-read the original post. I thought the display read either 13 point something or 14 point something but you're saying it starts high and drifts low.

The battery is slightly discharged after you start the car and the charging voltage would drop after the battery is brought back to full charge.

Try this if you like. Turn the lights on for several minutes and let the battery drain a little (not a lot!). The Escort should read around 14.8 V after you start the car. Then the voltage should slowly drop to around 13.4 V again but this time it should take a little longer since you've discharged the battery more than normal starting would. I'll bet the Escort reads slightly above 12 V when the car is off, right?

The better car stereo shops have oscilloscopes they use to "dial in" equalizers, signal processors, etc. It still might be interesting to see if the grounding kit "cleans up" the voltage by reducing inherent system noise.

 

or worst case in the long run alternator belts that are going will cause the voltage to slightly alter. i think it sounds normal though