Does a 1999 Blazer LT 4WD have a separate Voltage regulator or is it located inside the Alternator?


I think I need to replace the Alternator, but Autozone told me to replace the voltage regulator too. I subscribe to ALLDATAdiy, as was recommended to me by someone here in a previous thread. I cannot seem to find any information in there about replacing the Voltage Regulator.


I am seeing at times an oscillation in the volt meter in the dash between 13-14 volts during normal driving condition. I am not referring to the drop seen with using a directional, etc. I am talking about just cruising down the road and it waivers back and forth. Normally it stays pegged at 14ish volts all the time. Two days ago during a trip I noticed the volt meter steady at 12 volts exactly. don't know how long it was there before I noticed, but it went back to 14 volts after a short amount of time. I have never seen it do that before.


I assume there is a problem with the alternator, please correct me if I am wrong. I don't want to replace the alternator and not the voltage regulator or vice versa if the problem is with one or the other. the voltage regulator is cheap enough I don't mind replacing both if I need to.


thank you in advance for all your help.

 

It used to be that the alt. and the regulator were two separate items. Now the current GM alternator has the voltage regulator built inside the alternator. So when you replace the alternator, you are also replacing the voltage regulator!
Now theoretically, you could purchase just the regulator and if you had the skills and a manual, you could remove and open the alternator and take out the defective voltage regulator and replace it with the new one. But most technicians would advise you to go ahead and replace the entire old alt. with a new or remanufactured one.

 

Thanks for the reply Jimspahr,


Do you happen to know when the change occurred?


I am trying to find out for the 1999 blazer if it is located in the alternator or separate.

 

I called Advance Auto Parts for a 1999 Blazer alternator. The voltage regulator is internal. They have two 100 Amp versions and a 105 Amp. There is a core charge which you will get back when you return the old one. Sometimes it is helpful when you have your VIN no. to get the exact model alt. for your application. You could also upgrade to a larger 145 Amp alternator referred to as an AD 244, but that requires a different size serp. belt. It is a one inch longer belt. If you are interested, do a 'search' for that.

 

Thank you Jimspahr,


Appreciate your help!