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Discussion Starter #1
My alternator shows only 11 -12 amps on my gauge until I rev up the engine. But if I rev it up to say 5000 to 6000 rpm it immediately jumps to 13 to 14 amps according to my gauge. The blinkers are slow to blink at 11 to 12 amps, but when I rev the engine up to 14 amps they blink fine.
Since it has a built-in regulator, I was told that the regulator was weak, Is this possible?

Thanks for the help, Terry
 

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It sounds like you have a faulty exciter in the alternator. Once it kicks in, does it stay in even when the RPM drops?
 

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Amps or Volts?
 
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You removed the external regulator and orig type alternator ?
 

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Discussion Starter #6
Yes, I took the original external regulator and orig type alternator and replaced it with a newer type.
 

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It's a device that kicks the alternator into charging. You should be able to get yours replaced quite easily. Take the alternator off and take it to auto electric repair shop, should be simple and minor.
 

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Is this the original DN style alternator? Used form 1963-'74 it had an external mechanical points controlled external regulator.

The SI style was the first transistorized internal regulator and since transistors hate heat and varying voltages they where not too reliable in the older cases.

Newest fad is to use a one wire CS style alternator that uses the battery to only store a charge not run the car. As such you have to beef up the wiring to support the added amperage and rock steady voltage that a CS provides (developed in the late eighties to power a computerized car that needs a stable voltage supply to work). The newest alternator isn't going to work as well as a CS as it doesn't use standard brackets to bolt up.

If as I suspect you have an old DN then most likely you have blown the rectifying circuits and need to replace this part:

https://store.alternatorparts.com/3...7PF9zWGajCuX-UFOz7yHGwHD6YjylLaUaAkuQEALw_wcB

Big Dave
 

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Discussion Starter #11
To everyone one last note.

I need to give everybody some background on the car! It a 67’ Camaro 350 SB with 700R4 trans. The engine is out of 87 or 88 model (car or truck engine not sure) with vortex heads and electronic ignition. No A/C or radio.

I changed the alternator a few years back, removed the external regulator and original type alternator.

But for a while the alternator has been running at 12 volts until I rev it up, then it will jump to 14 volts. One more thing, I put it on the charger and leave it, until I get ready to drive or go to a cruise-in.

Sorry guys, I should have told all this to start with.
I do appreciate your help and support..
 

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Need to have it checked out at a Alt shop. The module is probably bad. My 2 cents
 

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The "exciter" is the internal regulator. The internal regulated alternators are set to not charge until they reach a set rpm determined by engine rpm's. After they get to tht rpm, and "catch", they stay at the maximum charge voltage until the system is shut down again, as in engine stop. Then, when the engine starts all over again, the same process is repeated.

If the charge voltage falls below the maximum voltage after the regulator catches, check the regulator being defective. Usually, the regulator catch is between 1,100 and 1,300 rpm's, which is actuated by the cold start choked engine, or, the first rev the engine gets above the capture rpm when hot.

I have spun up a lot of these alternators for my local auto parts store ( do a lot of that for them, nobody else knows how to doit there), and I can watch one that is working right actually catch and run when I run them up at first run on the machine. Most are at, or very near the 1,100 rpm level.
 

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I had the same issue when I switched from the original style externally regulated alternator to the next generation 3 wire 12SI internally regulated alternator.

You need to jump the wire harness where it used to plug into the external regulator. They sell plugs to cap it off but all you need is 2 short pieces of wire and 4 male spades. Jump the 2 middle wires together and jump the 2 outer terminals together. Now your Alternator will sense that it is spinning without needing to reach the high RPM.

Post#9 has a picture of it:
www.camaros.net/forums/19-electrical-wiring/396249-alternator-voltage-regulator.html

This site has tons of good info:
MadElectrical.com - Electrical Tech
 

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FAR more simple than that. ONLY needs a 14 gauge jumper wire on the back of the alternator from BATT to side terminal number 2, and with no charge light, DONE. If a charge light is desired, run the charge light wire from the old regulator connector charge light wire, to alternator terminal 1, DONE, light functions as it did with the old style alt/reg.

Please do not tall me that 9 miles of wire, all the way back to the power station is needed, it isn't. I have over 2K 12SI alternators running just like I outlined above, on GM, and all sorts of other maker's vehicles. 12SI 94 ampere alternator is my charger of choice.
 

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