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Discussion Starter · #1 ·
I was piddling with the Roadster tonight doing a purge cycle as I replaced the
water pump and wanted to get all the air out incase the weather cleared for this weekend’s poker run….. Anyway I thought I would check the voltage on the donor alternator so I checked it with the multimeter and it came out to 14.7v I’m thinking it’s a little high so I pulled other VOM out and it was 15.2v ( I guess Confucius was right “a man with more than one multimeter really does not know what voltage he has”)
So what is the correct voltage, engine on….. with a load or without +- .1 volts


Thanks
Ernie
 

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Discussion Starter · #3 ·
yea right.... the redundant dept of redundancy

oh yes tt
Well do I need to go to autozone or not..... ;)

Ernie
 

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Discussion Starter · #6 ·
Thanks Dale
I think it's about the last of the original donor parts......


Ernie
 

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Ford Fuel Injection & Electronic Engine Control by Charles Probst, the bible for 5.0's, says that with the engine running the voltage should be approximately 14.5 volts.
Cheers,
Mark
 

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Sustained voltage over 14.5 volts cooks the battery.
Frank
 

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14.7 does seem a bit high. I've seen numbers of 13.5 to 14.5 as "good" but this is at the voltage sense point. Depending on how you wired the alternator, this might be an issue or not. the reason I don't like 1 wire alternators is that they cannot increase output to make up for voltage drop in the wiring as load increases. Where are you measuring the alternator voltage? Do you get the same reading at the battery?
 
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