All suggestions and ideas are welcome. I'd rather overtest it, then not test something. I want to ensure the battery was the sole cause of my problem. Things I know - Batteries are 12V by themselves. While the engine is running, the voltmeter on a battery should be around 14.5V. Does anyone know how low it should go if I have the A/C on full blast (REC setting), or how much draw if I'm raising/lowering the convertible top? If I carefully remove the positive battery cable while the car is running, the car should remain running. GsThunder (Al) has suggested that this method may fry a diode. Is this true? Al has also suggested that, with the car running, put a screwdriver to the post in the back which should be magnetized if the alternator is running properly. Should I get an ampmeter? Thanks in Advance!
Marco, If you disconnect the battery while the car is running, the alternator will go to full max charge, blowing out the alternator and causing a possible fire :eek2: . NEVER EVER do that!! The only proper way is to hook up an ammeter to determine what charge is comming out of the alternator....if its below 13 volts, I believe that it means the battery is fully charged...if its over 13 volts, its charging the battery. HTHYO! :TU:
alt test Hi Marco There is a real easy test but you have to be very careful... Disconnect the small plug at the back of the alternator. This is the plug to the brush assembly. Find the "F" or field terminal on the alternator. Put your test leads from your voltmeter on the battery to measure the battery voltage. You should read about 12v. Leave them connected. Connect another lead from the positive side of the battery. Use another test lead if you have one. You can use any wire, but you need a small pin connector at the end for the next step. (Keep the free end from touching anything) Start the car. Touch the free end of the test lead connected to the plus side of the battery to the F terminal on the alternator. This will apply a full 12 v to the field coil. On the voltmeter, you should see the voltage on the battery immediately start going up as the alternator starts to charge the battery. This is the careful part as it it not easy to do, especially if you have AC.... As soon as you see the voltage going up, remove the lead from the F terminal. You can do it again to verify, but don't keep the lead on too long as the voltage will keep going up. Try not to touch anything else. This will tell you if the alternator is working. Also, with the engine off, you can touch the same test lead to the R terminal on the plug to the regulator and hear the ignition coil in the regulator click. This will tell you if thats working. Don't try this if the regulator is solid state.... Reconnect the plug to the alternator and you are done. - Bill :Comp:
gen There are two types of regulators: mechanical (large black box) and solid state (transistor, usually silver with fins). btw - what is your red charging light(idiot light) doing? If its on with the ignition on before you start the car, goes out when the engine starts and never flickers, you should be good! - Bill
Re: gen :TU: Thanks Bill. Yes the light is on with the ignition and goes out once the motor is running. I'm just trying to isolate the sole reason for my starting problems to the battery, and not a charging system that killed it PS - I have the mechanical regulator - large black box mounted on the firewall (OEM).
Alternator idiot light Seems my red ALT light comes on after the car is warmed up or when I shut it off and re-start.I think the internal regulator is bad or is it something else?.Should I replace the whole unit??
No! Marco, DON"T touch a screwdriver to the post in back of the alternator! Reread what I said please, touch a screwdriver to the center bearing cover.I wouldn't want you to short something out... :gt:
Regulators There is a post somewhere here on the board ( I think in Sparky's Corner forum) about how our original voltage regulators were mechanical with a point system inside. I switched to a solid state type voltage regulator which solved alot of my charging problems. The only problem was they looked identical exept for the cover (our original has Delco-Remy on it). I simply drilled out the rivets holding the solid state reg. cover on and put my old Delco-Remy cover on (it fit perfect). State of the art electronics and looks identical to original (bolts to the firewall just like yours). I just went to the parts store and asked for a voltage regulator for a 70 Buick Skylark and they gave me the solid state one(I assume thats all they make now)...:TU:
red light STAGE2GO (whats your name???) You can try what I told Marco - that will tell you if it is the alt. You might also have something simple like a bad connection. I recommend you post a new thread and say "help" in the title....you should get lot's of input! Marco & Al - yeah, I guess the new solid state ones can look like the original equipment. The only way to know for sure it to take the cover off: if it looks like a hunk of metal with circles cast in its solid state, if you see wires and points its mechanical! Or if the cover is riveted on its probably solid state. :TU: - Bill
Bill - I tried your alternator test last night and everything was exactly as you stated it should be. Thanks for the information :TU: I didn't test the regulator because my son (26 months) kept picking up my tools and I didn't have the time to determine if it was a solid-state or mechanical type unit, or to perform the other test. I have no reason to believe the car is overcharging as it is putting out 14.5 - 14.6 volts with the car idling about 800rpm. The real test comes tomorrow with the A/C on for a 90 minute highway trip (each way) :Brow:
Question - Is a solid state regulator better charging technology, and should I just replace my mechanical regulator with one?
Marco, a mechanical voltage reg. is greatly affected by heat. If you look at the factory manual, it tells you how to adjust and at what temp to do it. The problem I had was as soon as you install the cover after adjusting, of course the internals start to heat, thus changing the output setting. I chased the setting around for a while,but output voltage always seemed to vary from day to day. As soon as I changed to the solid state reg. output was rock steady and I've never had another charging concern....o No: I guess (like most things) ,it's a personal choice.
if it ain't broke don't fix it..... Marco - I would leave well enough alone. It seems to be working properly and there is nothing wrong with an OEM mechanical regulator if its working. When it dies I'd go with a solid state as they are better than the new mechanical units. - Bill
Marco- If you do decide to change the regulator it's no big deal. I bought a Wells VR715 at Autozone for $11.49. I swapped it in in about five minutes. I did so as a precaution as the original 30+ y/o unit was in the car. I figure having a bad charging system and risking damage to the HEI (I think this is possible) isn't worth the less than $12. I kept the old one and will switch over the cover per GS Thunder to make it look correct when I get a chance. Take care,
