How to change diodes in an alternator ?
07-10-2005, 08:53 AM
#1
Race Director
Thread Starter
How to change diodes in an alternator ?
My thanks to those who replied to my earlier post on how to diagnose my charging system problems.
It turns out that the alternator was intermittently putting out only 1 amp peak. The tester gave a bad diode pattern readout.
It was a strange situation. When the car was cold things seemed to work fine. 14.2V on the system readout, but when it got warm, Volts would start dropping. Funnything as each time I got near home, it would kick back in and start reading above 13.5V
I took it to Autzone for a free charging sustem test and got lucky, the readout was above 14.1V all the way there. Just as I pulled into the lot the system voltage dropped to 12.1V and the tester was able to diagnose the problem..... Hmmm on left turns it kicks in on right turns it kicks out.... could that just be a coincidence? any thoughts?
Does any one have any instructions on how to change out the diodes in an alternator for my '88? Is it possible that something is loose inside the alternator casuing this go/no go situation. All external connections appear tight and clean.
It turns out that the alternator was intermittently putting out only 1 amp peak. The tester gave a bad diode pattern readout.
It was a strange situation. When the car was cold things seemed to work fine. 14.2V on the system readout, but when it got warm, Volts would start dropping. Funnything as each time I got near home, it would kick back in and start reading above 13.5V
I took it to Autzone for a free charging sustem test and got lucky, the readout was above 14.1V all the way there. Just as I pulled into the lot the system voltage dropped to 12.1V and the tester was able to diagnose the problem..... Hmmm on left turns it kicks in on right turns it kicks out.... could that just be a coincidence? any thoughts?
Does any one have any instructions on how to change out the diodes in an alternator for my '88? Is it possible that something is loose inside the alternator casuing this go/no go situation. All external connections appear tight and clean.
07-10-2005, 08:59 AM
#2
It has been about 5years since I was in my 87's alternator. If memory serves, parts were not available to rebuild it. Rebuild kits are common for the older stuff. I had no luck on my cs-130 style. Check on availability.
07-10-2005, 09:11 AM
#3
I just saw your other post. Glad to see that parts are easier to get. My memory of the diodes is a simple plug in. When you reassemble the alternator, you must use the paper clip trick. The brushes are put in their holders and compressed. Then you slide in the paper clips from the rear. This holds the brushes retracted till you get the 2 halfs bolted together. Then you pop out the clips and you are all set.
07-10-2005, 11:49 AM
#4
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You might also have worn out brushes which is why it works on right turns and not on left turns. Find a local auto electrical shop and have them either sell you repair parts or rebuild your alternator. They are usually cheaper than a parts store rebuilt.
07-10-2005, 12:45 PM
#5
Le Mans Master
