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I have a 2009 base and the under the hood box has fuse #2 as the horn fuse and alternator sense, what is alternator sense? Also fuse #34 is listed as a horn micro-relay. thanks for any help with this
I have a 2009 base and the under the hood box has fuse #2 as the horn fuse and alternator sense, what is alternator sense? Also fuse #34 is listed as a horn micro-relay. thanks for any help with this
Based on the wiring diagrams of the C6, Fuse #2(horn/alternator sense) puts power to the alternator /charging system and also the horn system.
This is a pic of the horn system from (fuse #2)
When the horn is pushed on the steering wheel, it completes the horn control logic, energizing the horn relay coil (C2-E1) and pulling/latching the switch Dotted line putting power to the horn assemblies through E2-C1.
I added part of the alternator/generator circuit as well
I have a 2009 base and the under the hood box has fuse #2 as the horn fuse and alternator sense, what is alternator sense? Also fuse #34 is listed as a horn micro-relay. thanks for any help with this
Originally Posted by LV2TOUR
Based on the wiring diagrams of the C6, Fuse #2(horn/alternator sense) puts power to the alternator /charging system and also the horn system.
This is a pic of the horn system from (fuse #2)
When the horn is pushed on the steering wheel, it completes the horn control logic, energizing the horn relay coil (C2-E1) and pulling/latching the switch Dotted line putting power to the horn assemblies through E2-C1.
I added part of the alternator/generator circuit as well
The alternator sense line is part of the voltage regulation scheme. The sense line is connected (almost) directly to the battery and with the exception of the horn circuitry, has virtually no current flowing in it. The voltage regulator (inside the alternator) then sees battery voltage via a wire which has no voltage drop in it. This allows the voltage regulator to "sense" the true battery voltage without the effect of various current loads in the car affecting this exact voltage.
Why the horn circuitry is tied in with the alternator sense circuitry is anybody's guess other than it saves a fuse. History seems to show that this might have been done way back on GM vehicles with mechanical regulators and possibly even DC generators.
I hope this explanation helps and is not confusing. Had to think about it overnight before putting any words down.
Mack
Last edited by Mack1919; 11-17-2015 at 09:21 AM.
Reason: typo
The alternator sense line is part of the voltage regulation scheme. The sense line is connected (almost) directly to the battery and with the exception of the horn circuitry, has virtually no current flowing in it. The voltage regulator (inside the alternator) then sees battery voltage via a wire which no voltage drop in it. This allows the voltage regulator to "sense" the true battery voltage without the effect of various current loads in the car affecting this exact voltage.
Why the horn circuitry is tied in with the alternator sense circuitry is anybody's guess other than it saves a fuse. History seems to show that this might have been done way back on GM vehicles with mechanical regulators and possibly even DC generators.
I hope this explanation helps and is not confusing. Had to think about it overnight before putting any words down.
Mack
The section of the wiring diagram of this circuit that I did not show is exactly what you speak of.
11-16-2015, 12:15 PM
Fuse question
History seems to show that this might have been done way back on GM vehicles with mechanical regulators and possibly even DC generators. 
The section of the wiring diagram of this circuit that I did not show is exactly what you speak of. 
