Voltage Issue

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Oct 21, 2018 | 04:06 PM

Blazer112

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Voltage Issue

Great

Last edited by Blazer112; Feb 4, 2019 at 05:52 PM.

Oct 21, 2018 | 08:22 PM

cleburne red

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From: Texas

cleburne red will become famous soon enough

Quote:

Originally Posted by Blazer112

Hello,
Any ideas why the connector to my map sensor reads 70 volts? The base line connection reads the nominal 5 Volts. I have randomly check other electrical points and they read 12 volts. I have a 2004 Blazer ZR 2 and have owned it since day 1. My Blazer started missing badly while cruising at 40mph and the check engine light and subsequent scan identified the faulty sensor. I changed it but the problem persists. Thank you for your time.

I don't even see how that's possible. The battery is only 12v. There is no voltage higher than that in the vehicle, except for the ignition, and that's probably over 20k volts.

Is it reading 70vac or DC?

Oct 21, 2018 | 09:49 PM

Blazer112

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Joined: Oct 2018

Posts: 48

70 dc.

Thanks

Last edited by Blazer112; Feb 4, 2019 at 05:52 PM.

Oct 24, 2018 | 09:06 PM

cleburne red

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Joined: Sep 2011

Posts: 2,278

From: Texas

So, that's the only place you're reading that high of a voltage? Sounds like you need to spend a day tracing out wiring and figuring out where it's coming from!

You would think if it was the alternator, everything would be high, not just that one circuit

Edit: even if it were possible to be induction, wouldn't that be AC? Can't really induce DC, can you?

Last edited by cleburne red; Oct 24, 2018 at 09:08 PM.

Oct 24, 2018 | 09:35 PM

ChuckNTruck

Junior Member

Joined: May 2017

Posts: 352

From: North Dakota

Just to make sure, test you alternator and see if it is putting out any A/C voltage.
Many auto parts stores can bench test it for you for free.
https://www.knowyourparts.com/techni...-misdiagnosis/

Oct 24, 2018 | 10:50 PM

G0LFADD1CT

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Joined: Oct 2008

Posts: 325

From: Pasco,WA

G0LFADD1CT is an unknown quantity at this point

I would think that in order for the alternator to put out AC voltage the rectifier would be bad, but you would see high voltage in basicly the whole rig. Very puzzling.