Alternator Replacement

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1969_Valiant

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Hi everyone. My good mechanic friend confirmed that my alternator is smoked. Metal powder shavings on the back. I'm running an audio amp. Should I go with a stronger 60amp alternator, or will it start frying the rest of my electrical system? Its an all original design. Thanks for the help.
 
If you put much over 40 you need to think about the bulkhead connector/ ammeter bypass
 
Thanks for the reply man. It's a 300w amp btw. My friend also said to replace the voltage regulator, but didn't mention bulkhead connector/bypass. I replaced and checked the ballast resistor if that's what you mean. Obviously I'm not a mechanic, so excuse my ignorance.
 
And also, it's a 225 slant. Think 50 is safe without replacing components or blowing them out?
 
Not me. Read the MAD article whether you go that route or not. It explains the problem and why. Crackedback on here sells a bypass cable

Catalog
 
Thanks for the info. Well now you've basically scared me into a 45. What is the standard amperage for a stock 69 slant anyway? Again, I'm good at lifting things, matching threads, torquing bolts evenly, gapping plugs, draining n replacing fluids.....blah blah blah. In no way would I ever consider myself a mechanic or claim to be one. I know general principals about the average car. That's basically where my knowledge ends. And again, I appreciate all of the good knowledge on these sites. Thank you for taking the time to try and help me with my problems.:thumbsup:
 
I always run a separate "fused" power wire to my amps (from battery to amps). Never through any factory wiring. It shoudn't affect the voltage regulator if wired separately???

Treblig
 
Well yeah it does affect, because all the charging current goes from alternator ..........through the bulkhead connector..........through the ammeter..........and back out again. That is "most of" the problem

You are actually better off taking the added accessories power right off the alternator stud
 
Ok thanks again for all of the good info. I will talk to my mechanic friend and try to get things done.
 
Unlikely the amplifier caused your alternator to fail. If your battery was staying charged over a week of driving, your alternator was doing its job. Not sure what the metal powder on the back of the alternator is. Perhaps it is just oxidized aluminum (white) from the case. Doesn't sound like a typical failure mode. Why do you think the alterator is not working? The dash ammeter (charge to discharge marks) is for monitoring that.
 
I have a separate wire with a fusable link going to my amp.


Here's the question. Where does this wire tie into the system?

If the amp is drawing from the starter relay or the battery, then that can be a problem. The ammeter won't read charge/discharge correctly and if the audio amp draws high load, then the what should be just a charging circuit can get overworked.

If the amplifier is pulling direct from the alternator or the fuse box and the engine is running, the ammeter & wires to it are uneffected. If the amp is run with the engine off, then the ammeter circuit can get in trouble and should be bypassed.
See this: Understanding Charging Systems with Ammeter
(and if the whole Volt - Amps thing needs refreshing, this post)
 
a stronger 60amp alternator, or will it start frying the rest of my electrical system
The alternator's max output is only indirectly relevant.
1. The alternator only delivers what is demanded by the equipment. You can put a '60 amp' alternator on and if the only power needs are the ignition coil and alternator field (about 5 amps at 14 Volts), then that's all it will put out.

2. In many cases, and this would seem to be one of them, the important thing is to use an alternator that puts out enough power at idle speed to cover all the needs. Some higher output alternators are also better performers at idle speed. This would be what is you want if the amp is drawing more than nominal power anytime the engine is idling.
 
I put a 60amp in my '73 and the only issue I had was related to that damn bulkhead. Replaced that wire and bypassed the bulkhead connector and haven't had any issue since.
 
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