Cold Weather Voltage

[JimW]

Most recently I have noticed my voltage running a bit higher then normal.

Normal operating voltage while driving is 15.1 Volts, now since it got colder..15.3-15.4 V

Does that sound normal? What are others getting?

[Isnibs]

Yup I noticed mine the other day, it's the same as yours.
Sadly however my MPG is dropping, I only drive about eight miles to work. Soon be time to plug in at night. Ho Hum.

[Rocketv8]

same thing, jim....normally about 15.1, and this morning here in NJ it was 33 degrees F and my voltage read 15.4.....always happens when it gets cold......and, as Isnibs said, my mileage has also droppeed with the cooler weather....was getting like 16.5-17.0 MPG city...now dropped to like 15.5mpg city

[JimW]

I surely do not want to see anymore then 15.4V, thats teeming on dangerously high voltage levels. I'll be plugging in tonight

I hope my grounding kit that gets installed next week eases the load of my alternator, might be time to look into a new battery as well. *sigh*

Winter is so killer on my car. I only drive 5 kms to work (one way) but at least I pleasure drive as much as I can. I'll keep you all informed.

[dred98]

JimW said:

I hope my grounding kit that gets installed next week eases the load of my alternator

What's a grounding kit and what does it do?

[JimW]

Supposed to improve electric flow, improve throttle response, brighten up lights. Check the Grounding Kit thread at Oldsforums in the Intrigue section.

[stevensolds]

jim can u install that yourself and how much is the kit in US dollars?

[JimW]

Yes and yes, Its getting installed next weekend, takes about 2 hrs tops, I will be doing a full review of this project and I will find out how much he wants to sell the kits for once he works on his first Aurora (aka mine) right now he is selling the 3.5L custom grounding kits for $20CDN + shipping.

Back on track for a moment, I will be plugging in tonight and noticed my operating voltage did not exceed 15.2V tonight (ambient air temp, zero wind chill) of 3C or..hrmmm effin Imperial oh about 37F?

[Letitroll98]

JimW said:

I surely do not want to see anymore then 15.4V, thats teeming on dangerously high voltage levels.

Dangerously high for what? And whom? The electrical system should run well over 24 volts peak at almost any amperage the alternator will produce, and certainly will run 16-18 volts constant for any reasonably short period. Who is telling you that what will be damaged?

Dred, the "grounding kit" is for removing ground loops inheirent in car engines. You can probably do just as well running a conductive string from your engine block to the ground. However I doubt if there is any real improvement here. Any residual ground potential in your engine is swamped by the impact voltage of the ignition system. But it may give you a warm and fuzzy feeling, and that could be worth $20cnd.

[stevensolds]

LMFAO

[dred98]

I set my D.I.C. to read volts all the way home from work today - about 45 minutes - and it was 15.4 or 15.5 volts all the time.
So, is that OK or not ?

Thanks for the info on the grounding - I'm still not sure whether it's necessary or not - but it sounds like another DIY project for my website - right Jim ?

[JimW]

I take it Mr Letitroll is still recovering from his cold

I had heard nothing but positives from those who have a grounding kit or those who considering it. I'm sure it will yield SOME improvements. Depends on how you look at it, its definitely not a 10HP mod, but just another way to get more out of your car...essentially improve what is already there.

As for the voltages, I have never seen it that high before, 15.1V has been pretty standard, so seeing something higher sets off red flags.

Hence this thread.

[SupaStealth]

yeah, i agree with letitroll on this one, our car uses a pretty hefty 4 gauge ground, but there is a bit of wire run since the battery is under the rear seat, but i don't think it would be enough to require a second (let alone a third)chassis ground up near the engine bay, but hey, if ya have some extra 8 (or larger) gauge wire layin' around, it might not hurt if ya feel that it would really help ya

oh, also, i just remembered most cars already have a ground up there on the engine, usually is attached to the firewall or an inner fender, at least the last 4 of my cars did.

[Letitroll98]

Was that harsh? Jeeze, I'm going to have to start using more "bleh" "harumph" and smileys from now on. My statement stands except for one modification I learned while reading the links you forwarded me to. I couldn't say it better than kimbo did on that thread so I'll quote:

"1) From the factory schematic (and getting under my car), there are two large cables from the negative battery post: one huge wire (about 00 gage) going directly to the engine near the starter motor, and the other (about 4 gage) going to the frame just under the battery. Therefore, I don’t see what the wires shown in post #3 going from alternator to the battery and from the batter to the rt shock do, as they just parallel the two factory cables mentioned above.

2) I don’t see the reason to connect ground wires from the engine to the MAF sensor body as shown in post #3. The MAF sensor circuit does not use the MAF body as a ground return path, rather it has its own ground wire in the harness connector (as shown in schematic on pg 6-561 of shop manual). I verified this circuit is isolated from the MAF body by removing the MAF connector and tested the resistance between each of the three MAF sensor pins and the MAF body with an ohmmeter and all were “open.” Therefore, why add ground wires to something that does not carry any electrical current in the first place?

3) The same analysis applies to the throttle body. There are two sensors attached to the throttle body, the Idle Air Control Valve Sensor and the Throttle Positioner Sensor. As shown in the factory schematics (on pgs 6-561 and 6-559 respectively), neither of these circuits use the throttle body as a ground return path. As with the MAF sensor, I verified each sensor was isolated from the throttle body by removing the connectors, and indeed the resistance between each sensor pin and the throttle body was “open..”

As I see it, all the car’s accessories (lights, stereo, heater, blowers, wipers) use a ground path to the frame, yet get their power from the alternator. Therefore since the alternator is connected directly to the engine, a ground wire from the frame to the engine may help supplement the two battery ground cables mention in the first paragraph, since neither of those connect directly between the engine and frame.

I will say that since installing the ground wire between the frame and engine that I have not noticed any flickering of my headlights. However, before I am convinced that the ground wire is responsible, I would have to wait a few more weeks as the flickering was always somewhat intermittent. Maybe I will disconnect the ground wire and see if the flickering returns."


My modification is of course the last paragraph. I told dred that a conductive wire from the engine to the ground would do as much, kimbo states that his connection from the engine to the frame works as well and that makes sense.

Now if you want to go around and clean up the existing ground wires that's a great idea and would probably help alot. The need for 10ga tinned audio wires is also hocum. These are stray electrical currents, not primary conductive paths. 16ga hookup wire from Radioshack would do just fine, as would any zinc connectors.

I also liked the note about proper engine grounding helping with the Dex Cool issue. This makes sense. So clean up all existing grounding wire connections, put an extra ground wire between engine and frame, save $20cdn, get same warm and fuzzy feeling. All this being said, there is no inheirent danger in this mod other than misrouting a wire and getting it wrapped around a moving part. So all those inclined, go for it and prove me wrong, I'd love it.

[JimW]

I'll give it shot either way.

If it is indeed hocum, as you stated, then so be it, I wont validate the product or the project. I am getting the work done for free, and I'll learn a thing or two about vehicular electrical systems. Bare in mind, I am not an electrical engineer or an electrician and I wont pretend to be one, all of this (and both sides of the story) is good information.

[Letitroll98]

JimW said:

I'll give it shot either way.

If it is indeed hocum, as you stated, then so be it, I wont validate the product or the project.

Oh yes, at this point go for it. The downside is nothing. However you won't know if a simple additional wire grounding the engine to the frame would have gained the same (expected) improvement. If you do see improvement we can go further with the experiment.

And please be advised that I'm not perfect (I know this is a shock, but live with it). If I have overlooked something, which with high tech aluminuim engines is very possible, then this could be a real boon for almost no investment. I'm looking forward to your report with great interest.

[Aurora40]

Letitroll98 said:

Dangerously high for what? And whom? The electrical system should run well over 24 volts peak at almost any amperage the alternator will produce, and certainly will run 16-18 volts constant for any reasonably short period. Who is telling you that what will be damaged?

I would be impressed if the PCM could still operate properly with over twice the expected voltage being supplied to it. The alternators voltage regulator should keep the voltage from going over 15.5 or so, I believe. I don't think 15.4 is anything to worry about. I would be worried that something wasn't working right if it got to 16, but it seems what you are seeing is normal behavior.

I've often wondered about the usefulness of a grounding kit also. The factory grounds are not insubstantial. And I can't see how better grounding would somehow lower your system voltage. If anything, really crappy grounding with really dirty connection points would be what drops your voltage down.

Let us know how it works Jim. And thanks for sharing your thoughts Letitroll, it's very interesting.

[dred98]

I read the info on Oldsmobile Forums and it doesn't appear to have a downside - except for the money, and that's not very much - but it looks like all this does is improve on the original ground that may have become less efficient after a few years. So I can see it making an improvement on some older cars. Which some of us have
I don't see it reducing voltage output though. The FSM says problems could occur below 9 volts or over 15.5 volts, so I'm right on the border line.
The next question I suppose is how accurate is the DIC reading.

[JimW]

Despite the balmy 0C--1C tempertures tonight I have plugged in the car, hoping the block heater works.

Update on the voltage, I took a 200 mile (345 km) drive today (brutal weather on the way back) but voltage never exceeded 15.1. I'll keep watching.

Thanks for the FSM reference Howard, I'll have to read up on that.

[chaqueno]

I came across a DIED 98 black Aurora yesterday. I had just towed a car to St. Catharines and upon getting back on the highway I saw the stranded Black Beauty on the on ramp. The young girl was beside herself because she had begged her mom to let her use daddy's car and now this. Apparently the gauges had all gone crazy and then the car just went for dead. It started a few minutes later but then it shut off again she said. I got it started and the voltage was at 14.8 but still did not want to take a chance so I put it on the Flat Bed and towed it to a garage in Niagara Falls.
Talkin to her dad later, he said that his mechanic had mentioned the ground cables should be looked after soon. Mine did the opposite in the Summer. My voltage reading was down to 8volts. I had our Batterie Van swing by and test the system. Batterie had required cold cranking amps. We were right it was my alternator.
Talking to our Bat. Van guys they tell me that it is normal for a car like ours to run around the 15 volt mark(mine runs 90% of the time @14.9 volts) If it does 16 to 18 volts, then we are overcooking the Batteries ( had a Caravan the other day that had exploded the batterie while driving and what a mess in the engine bay. Her alternator was cooking out 18 volts)
Our cars have quite the electrical system and hence also in the winter it will take a bit more for the whole system to run and operate. As to ground wires: it would not hurt to replace the ground wires in the engine bay every 6-7-8 years. Corosion usually starts at the exposed ends. I know my old T-Bird had the grounding problem. But nothing an hour or 2 and a couple of feet of new wire won't fix.
Also does someone know if it is true that the Aurora will shut off if it does not have 12.5 volts going through the regulator??