Crossbreed here, 1977 Riviera with the Olds 403. I’m having alternator issues. I have added another battery and a high output alternator to the car, (had it built by a local shop), after killing a few OEM Replacement alternators from O’Reillys, and since it was installed, I’ve had problems. With the OEM replacement, everything works !except! it squeals to high heavens when under a heavy load. (Aftermarket stereo, amplifier, etc) AND my generator light stays ON. With the H.O. alternator, the gas gauge doesn’t work, it doesn’t seem that the batteries are being charged, but it keeps the car running, and the generator light is OFF. (As it should be) At first, I thought it was a hot-start issue, because it would start once, run for a bit, and then after I turn it off, I turn the key and get a half turn and then clicks. The starter is relatively new, though. When I jump start the car, it doesn’t require “charging time,” the starter whirls, and it fires right up. Is it possible that I’ve killed the 2 batteries with all of my tinkering? But when I think about that, I remember not having these issues with the other alternator, just the squealing, and the generator light.
sounds like your stereo + amp are drawing too much juice. U need to check the amps being drawn with lights, stereo, amp, etc., to see if the amp draw exceeds the alternator max amperage. I do believe I have heard alternator whine when the draw is too much.
I struggled with my 77 403, and many other late 70s Olds small blocks, with slipping alternators. But apparently the General did too, and finally did something about it. The sketch shows the 70s arrangement at the bottom, and the 81 and later arrangement at the top. For 81 A LARGER DIA pulley at the water pump drives the alt. With no third pulley, this belt has MORE DEGREES of wrap around the pulleys, better traction. The LARGER DIA means less pull on the belt to make it slip, and with the alt speed stepped up, the alt does not need as much torque to generate the same amount of power. If your alt has a smallish pulley (no they are NOT all the same), a larger one (say, 1/4 inch larger dia) may be used without loss of alt rpm. I finally converted all 5 Olds engines to this setup, what a relief. How, the last decade of Olds small blocks have the parts. The accessories stay put, but the crank and water pump pulleys change. Oh, and the power steering pump goes from 2 grooves to one. I just grab that from the later car, but there is ONE PROBLEM. This pump has a metric pressure hose fitting, but your 70s steering box has an English fitting. FORTUNATELY the metric fitting UNSCREWS from the late pump, and your English fitting from your old pump goes right in, use your original hose. Alt wiring, more later. Bruce Roe
Bruce, thank you. I actually took the (160A) alternator back to the shop that built it, and he replaced the larger pulley with a smaller pulley. His reasoning being that my idle wasn’t fast enough for the alternator to perform with a larger one. I’m going to study those diagrams and dig in. Thank you, again. GStewart, thank you. It’s a 160A. But you’re right, I’ve never actually checked to see. I was told “160A” oughta be plenty. My fault.
Went a bought a new control alternator, just in case. (OEM replacement 63A). It’s doing the same thing the other 63A did. (I’m not suprised) squeals like he//. (I unhooked any accessories). The gas gauge works again. I don’t get it. Why would the aftermarket alternator: A) keep the car running, but not charge the batteries. B) not allow my gas gauge to work.? C) turn my alternator dash light OFF. The OEM alternators: A) charge the batteries. B) gas gauge works. C) squeals like he//. D) keep the alternator dash light ON.
Turn key to run position, do not start the car. Do you have an alternator light on on the dash in this position?
Ar first look it seems you have a blown charge indicator fuse. OEM alt (A) alternator is working (C) Probably belt squeal - multiple - Alternator overloaded (power demand too high), bad belt , wrong belt width, loose belt. (D) Indicator light on- Alt working with an open charge lite circuit - probably fuse. (B) not sure unless fuel gauge works off of same circuit as charge indicator lite. Aftermarket 160 amp. (A) Alt not working. When batteries get low enough car will stop running. (C)Blown charge fuse alt not working. (B) Alt not working and is on same circuit as charge lite. Aftermarket alt may have a 1 wire regulator in it. Tell me which alt is on there now, and I will try to give you the fastest and easiest way to test.