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Discussion Starter · #1 ·
What is the correct system voltage for a 2021 latitude 4 cylinder. Mine is reading 12.6 with the engine on or off. Makes no difference if the engine is at idle or at 1500 rpm, lights on or off, AC on or off. I checked with a known-to-be-accurate DVM. All readings agreed.
I’ve been working on vehicles since 1965, never seen one like this. Anything below 13 V above idle says regulator or alternator (or generator, back in the day).
 

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That is a good question. You are right, back in the day an alternator would read 13V or better and a battery at 12V. However I have noticed that I have a system at 12.5V when running and same when off. The difference is that I have batteries with AGM technology and they will accept and hold a charge of 12.5V. Tech has changed now, but I don't know what battery you have. But I wouldn't worry about it
 

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Discussion Starter · #3 ·
That is a good question. You are right, back in the day an alternator would read 13V or better and a battery at 12V. However I have noticed that I have a system at 12.5V when running and same when off. The difference is that I have batteries with AGM technology and they will accept and hold a charge of 12.5V. Tech has changed now, but I don't know what battery you have. But I wouldn't worry about it
Thanks. It is one of the age batteries, so I guess that is how it was designed. The issue is that much of the current crop of amateur radio gear designed for “12v operation” really wants 13.5 to 14 volts for proper operation, since that is where older lead acid battery systems operate with the vehicle engine running. The radio I have is notoriously problematic at the lower voltage. Guess I’ll be doing some shopping.
 

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Not real familiar with the alternator on the new stuff. I have a 250 amp aftermarket that runs at 12.6V. But in your situation I would consider taking my alternator to a shop that specializes in rebuilding alternators and have them do a little work on it. However, many of the Cryco alternators are controlled by the ECM. If that is the case, it would take an external voltage regulator or a re flash, which may not be available
 

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Not real familiar with the alternator on the new stuff. I have a 250 amp aftermarket that runs at 12.6V. But in your situation I would consider taking my alternator to a shop that specializes in rebuilding alternators and have them do a little work on it. However, many of the Cryco alternators are controlled by the ECM. If that is the case, it would take an external voltage regulator or a re flash, which may not be available
I’m pretty sure the ECM controls the alternator on the new models. I’m still looking for a shop or maintenance manual that doesn’t cost a fortune. The only reference I’ve found so far says it will be available late September and costs over $200.
There are also step-up/step-down converters that keep a steady 13.5 to 14 volt output with the input voltage between 11 and 15 volts. They are used in marine applications where the electronics may be powered by batteries when the engine is shut down.
Guess this old guy will have to learn some new stuff. Thanks for the advice and response.
 
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