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Scanguage volt reading

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Old Jun 9, 2016 | 08:30 PM
  #1  
firedaniel's Avatar
firedaniel
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Scanguage volt reading

I've had a scanguage on my truck for years and today while on vacation I noticed the voltage was fluctuating between 12.5-13.5 while driving. It has always ran at 13.5-13.7 I checked it with a fluke and it is a solid and steady 13.8v at idle. Why would that gauge be fluctuating like that? Truck seems to be running fine.
 
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Old Jun 10, 2016 | 07:52 AM
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Scan Gauge reads low by about .5v, at least mine does. Could be the A/C clutch locking and unlocking, check the Freon level in the system.
 
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Old Jun 10, 2016 | 12:13 PM
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My voltage is usually at least a 1/2 volt less on my Dashboss at the obd port vs using a vom at the alternator terminal.
 
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Old Jun 10, 2016 | 03:45 PM
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Originally Posted by firedaniel
I've had a scanguage on my truck for years and today while on vacation I noticed the voltage was fluctuating between 12.5-13.5 while driving. It has always ran at 13.5-13.7 I checked it with a fluke and it is a solid and steady 13.8v at idle. Why would that gauge be fluctuating like that? Truck seems to be running fine.

Just for good measure, pop that hood open and double check the connection to the back of the alternator.

Once in a blue moon they can for some reason come loose, and if that's the case it will make that big fluctuation.

I know this from personal experience.
 
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Old Jun 11, 2016 | 04:00 AM
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I'd be looking at the alternator, it could be time for a new one, the regulator could be starting to go out. That is if all connections look good.
 
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Old Jun 11, 2016 | 04:29 AM
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From: Spanaway
Or it could be just a fault of the SGII. Give them a call and see what they think.



Sean <BR>

6.0L Tech Folder
 
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Old Jun 11, 2016 | 09:30 AM
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My Scan Gauge 2 voltage reading is about a half volt lower than with my fluke.
 
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