Scangauge II readings

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BManning`

BManning`

Joined
Oct 29, 2005
Threads
32
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323
Hooked up my Scangauge II to the 100 just before a recent southern Arizona road trip (about 600mi round trip):steer:

*Hottest temp was 204, typical op temps were 193-198. I think the 204 was read after a quick restart after a long run, because I don't remember it breaking 200 while I payed attention. Temp likely surged a few degrees in the brief time it sat on a fuel stop.

*Volts read anywhere for 13.3 to 14.2, but most commonly around 13.3-13.5. Has me wondering if my battery is getting weak. Shouldn't I be closer to 14V consistently? :hhmm:Starter spins pretty quickly still, but I know batteries can conk on a dime.

*Wasn't meticulous about it, but according the the scangauge and also figuring Miles Driven divided by Gallons Used, I saw anywhere from just over 14mpg to a bit over 17mpg-- wife 120lb, 2 dogs combined 100lb, luggage maybe 60lb, my 215lb butt, driving 75-82mph most of the time (75mph limit out west :cool:) with some elevation changes. 91 octane used throughout, as always. I can live with those MPG at those speeds to enjoy the safety, comfort, and performance of the LC.

My question is: what scangauge readings are you other SG owners seeing (as far as eng temp & volts)?

My statement is: my Lord, the 100 is almost a perfect long-distance road tripper! (especially now that I've hooked up my XM...)
 
My Scangauge reads nearly the same. Voltage always hangs around 13.6 and Temp between 188 and 197, usually around 191 with a load like yours.
 
Voltage is telling you what the ECU is seeing, not what the actual voltage is at the battery. Actual voltage at the battery is typically higher.
 
The voltage will drop off as your battery becomes fully charged and the alternator output reduces.
 
The highest temp I have seen was 191 and that was during a 3hour wait at the border with a 113 degree outside temp. Watching the people sweating in the brand new Cadillac Escalade with its windows down next to me - priceless

I find that my intake temp runs about 10 degrees higher then outside temp

Running the Norcold frig I see 15.1volts a start up to get my battery back up. norm is 13.5volts

I calibrated the MPH on my SG to adjust for larger tires- Found to be more accurate to calibrate in KMH and switch back to MPH.

I watch the load determine what gear to use pulling my trailer up the hills.

Not sure the SG is worth what you pay for it but it does give me something to do when Im driving.
 
wildsmith said:
The voltage will drop off as your battery becomes fully charged and the alternator output reduces.
Click to expand...

That's not correct. The current will drop off and the voltage will increase...they're inversely proportional. The higher the load and thus current, the more difficult it is for the alternator to maintain the voltage regulation setpoint. As the battery absorbs current, and once the internal impedance decreases and the voltage regulation setpoint is achieved, the alternator will continue to maintain the elevated voltage setpoint as the current load will be minimal. If your alternator typically charges at 14.3 volts, and you turn on lights, heaters, etc...your alternator will increase current output to match the load, and voltage will typically drop to say 13.7 or so. Turn off all those loads, current backs off as battery is charged and voltage stays at the voltage regulation setpoint.
 
mobi-arc said:
That's not correct. The current will drop off and the voltage will increase...they're inversely proportional. The higher the load and thus current, the more difficult it is for the alternator to maintain the voltage regulation setpoint. As the battery absorbs current, and once the internal impedance decreases and the voltage regulation setpoint is achieved, the alternator will continue to maintain the elevated voltage setpoint as the current load will be minimal. If your alternator typically charges at 14.3 volts, and you turn on lights, heaters, etc...your alternator will increase current output to match the load, and voltage will typically drop to say 13.7 or so. Turn off all those loads, current backs off as battery is charged and voltage stays at the voltage regulation setpoint.
Click to expand...
I'm pretty sure it is correct, we're talking about the system voltage here not alternator.
 
According to my Scangauge my voltage was approximately 13.5V. Having replaced the alternator brushes in my 80 the voltage now sits at 14V.
 
i did about 1200kms over the long weekend here and my Scanguage voltage reading sat between 13.3V and 13.6V.
When my auxillary battery was on it's way out (i posted about that here) the reading was between 13.6V and 14.2V.
temp was showing 86C which is what it normally shows.
cheers
peter
 
When your alternator is cold it will output higher volts, as it heats up it's output gets lower, mine is typical 14.2 volts at startup in the morning, on trips it ranges from 13.3 to 13.8but mainly hangs around 13.5.
 
I drive my LC more than usually (1000 miles/week, and I have the same Temp issue.
I checked every 5 minutes, and never saw temp over 85/86°C ...
But, if I check the "Today" or "previous day max", I can read 90°C or so

Not a big deal (185/186 and 194°), But I think it's weird...
I tried to test that point... after being arrived at home, I stalled the engine, waited 2 minutes and put IGN on.
The temp was the same as when I arrived...
 
Well, I have discovered a stupid Scangauge problem with the 100. With the location of the OBD port right above your foot, it's easy for the Scanguage cable to get bumped. If the truck is off and you connect the cable, the Scangauge will power on and attempt to connect to the ECU, seeking information. It will do this continuously, no time out. Well, it's enough power to kill your battery in a few hours. It's happened twice now, so I'm going to be zip tying the thing securely tonight.
 
moooooooo said:
i did about 1200kms over the long weekend here and my Scanguage voltage reading sat between 13.3V and 13.6V.
When my auxillary battery was on it's way out (i posted about that here) the reading was between 13.6V and 14.2V.
temp was showing 86C which is what it normally shows.
cheers
peter
Click to expand...
Exactly what happens today to mine, which suddenly, after 15 of radio listenning, goes down without other premice than little "kwirks" heard through the HP and then no sound (but radio still on), no more start. (everythings was right this morning and days before)
I started, helped by another car, and the scangauge says 13.6 to 14.1V
 
Don't ever give up...
After an overnight charging, everythings looks ok.
(tested on 80 miles and 10-15 start)
SCII says 14.1 after start to 13.6 after 10-20 miles
 
it's perfectly normal for the coolant temp to increase (easily by 10F from what I saw) after you turn the engine off if the engine temp is up there. The coolant is just soaking heat from the hotter metal...

Why don't you put a voltmeter on the battery or alternator and read that against the SG so we know the difference? That'd be interesting.
 
Done...
While the SCII said 13,5 to 14,1 volt, the real voltage was 13,78 to 14,19.
But without evident relation... some measurements I took during the test day:
SCII Real
13,5 to 13,7 = 13,86 to 13,90
13,7 = 13,86
13,8 = 13,88 to 13,92
13,9 = 14,10
14 = 14,18
14,1 =14,19

The SCII is definitly not a voltmeter !
 
OursSauvage said:
Done...
While the SCII said 13,5 to 14,1 volt, the real voltage was 13,78 to 14,19.
But without evident relation... some measurements I took during the test day:
SCII Real
13,5 to 13,7 = 13,86 to 13,90
13,7 = 13,86
13,8 = 13,88 to 13,92
13,9 = 14,10
14 = 14,18
14,1 =14,19

The SCII is definitly not a voltmeter !
Click to expand...

that's pretty close. Good enough for govt work! :)

was that at the battery?
 
Yes, pretty close, but in real life, with only 13,5 you could imagine having a regulator issue.
The error rate is not the same, neither proportional.
Anyway, as you said, its enaough for having an idea, especially if you know 13,5V could be 13,8.

Not on the battery, I'm use the lazy way... a multimeter linked to the accessory plug.
More convenient for reading all along the day
 
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