[Trent7276]

When I put on the brakes with my headlights turned on, everything flickers for a moment and goes a bit dimmer (headlights, instrument lights, etc) Same when releasing them but it gets brighter, not much though. Also sometimes my stereo will turn off and back on when I hit the brake lights with 2 accessories on, such as headlights, radio, wipers. Also the radio cycles again when just switching between BRIGHTS and LOWS. How can I stop this for good, it's now getting annoying after 2 years. Ha!

Trent
1968 Firebird 400 Coupe

Trent
1968 Firebird 400 Coupe
Muncie M-22 "Rockcrusher"

[Trent7276]

When I put on the brakes with my headlights turned on, everything flickers for a moment and goes a bit dimmer (headlights, instrument lights, etc) Same when releasing them but it gets brighter, not much though. Also sometimes my stereo will turn off and back on when I hit the brake lights with 2 accessories on, such as headlights, radio, wipers. Also the radio cycles again when just switching between BRIGHTS and LOWS. How can I stop this for good, it's now getting annoying after 2 years. Ha!

Trent
1968 Firebird 400 Coupe

Trent
1968 Firebird 400 Coupe
Muncie M-22 "Rockcrusher"

[Fox]

Probably has to do with your alternator not providing enough current or your voltage regulator is the external type and needs to be replaced.

[Txbobcat]

I agree with Fox but ad if not an internal regulator alternator throw it in the trash and make the switch to a later model alt. Also check battery cables for cleanliness making sure they are tight and check grounding straps as well. Your radio is going off because they are engineered to go off when voltage is too low.

[68CONV400]

I agree with all the other posts.Either a bad diode in the alternator (w/internal regulator) or a bad regulator (external).

Charlie

[68CONV400]

Or a dirty or loose ground.

Charlie

[Trent7276]

I've got the stock replacement alternator, 1 yr old so I think it must be the regulator (didn't replace that yet). I'll pick one up from Autozone. Anyone know what is the largest alternator i need for all accessories (tach, a/c, electric water pump, electric fans, 5 channel 400 watt amp with subs and nice stereo system? I was thinking 140 amp alternator to cover it, what do you think? Will it fit under the hood just like the original, bolted to the same bracket? Thanks!

Trent

Trent
1968 Firebird 400 Coupe
Muncie M-22 "Rockcrusher"

[george kujanski]

With all that stuff, put in the highest rated one youy can find. Over 62A, I believe higher rated alts are the larger frame size (Delco 12SI, internally regulated) from later model years. I would not get one of the uprated small frame alts as these probably have poor output performance at low engine speeds in favor of high output at higher speeds. You don't get something for nothing.

Regards, George

[WallyB]

You should probably start at the begining and realize that your stereo could suck 3/4 of the available current from a 60 or 70 Amp Alternator. Maybe run a second battery in the trunk just hooked to the stero and use it with an accessory isolater (blocking diode) - mainly for RV's. This will not allow your stereo to use tha cars main battery so it will not run down & you can start it and have everything else work the way it should. The stereo's battery will only get topped up after the main one is topped, not to strain the alternator. Just a suggestion.

Wally