current draw testing

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juki48
Posts: 473
Joined: Wed Apr 04, 2007 11:04 am
Location: Upstate NY

current draw testing

Post by juki48 » Tue Apr 22, 2014 8:47 pm

today I borrowed a fluke clamp on DC current meter to see what the load was on my alternator. I have an efi turbo so there is lots going on. at idle..


parking lights 5.8 amps
with low beams 13.2 amps
with high beams 14.7 amps

wipers on high 6 amps
wipers on low 4.1 amps

fuel pump 7 amps!
intercooler pump 1.8 amps
intercooler fan 2.8 amps
turbo scavenge pump 2.5 amps

so with everything on high the total plus the ecu is right around 35 amps! at idle the alternator was only putting out 27-30 amps. fortunately I don't think I'll need everything on high at idle so I have just enough power to keep the battery charged at idle. once I revved up the engine the alternator bumped up to 50 amps, what it is rated for. the draw on the battery was still around 35 amps leaving only 15 amps to charge the battery. I try to only drive during the day in nice weather so most of my driving only requires around 14-15 amps. still, when the time comes I'll be getting a higher output alternator.
Riley

74 Ghia 2276 Turbo MSII Extra
67 Beetle in restoration
Manx Style buggy 1600 stock

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