1995 Chevy Caprice Dashboard voltage needle goes from mid-r

TED.KING

MEMBER
1995 CHEVROLET CAPRICE
V8
2WD
AUTOMATIC
18,800 MILES

I have a 1995 Caprice Classic 5.7 L V8 with 188,000 miles. The dashboard voltage needle will swing from the mid-range to zero, and the headlights will dim. This will happen sometimes when I depress the brake pedal. Others times it occurs while driving on the highway and will actually lose power, stall and then restart itself, if the car is moving. If this happens when standing still, the car will shut down. I can restart it, but sometimes if I touch the brake, it will shut down again. I have found that when the voltage needle goes low, if I put a load on it by turning the blower fan on high, or use the electric seat adjuster, the needle will return to the mid-range. I had the alternator replaced about 4 years for this same problem. It is such a ghost of a problem, that comes and goes, plus I don't drive the car more than 6 times a month. So I thought replacing the alternator fixed it. About a year ago, I had another mechanic check to see if it had a good chassis ground. That was ok, but he said my water pump was leaking, and likely causing the alternator belt to slip. He replaced the water pump and belt. No change. In the last year it has become more frequent. Also, I have had times when it is damp out, when It won't start. Almost as if it were flooded. If I waited a day or so, It would start ok. I had the distributor cap replaced about 5-6 years ago, for a similar no start problem, after going through a car wash. I just replaced the 6 year old battery when it needed a jump start. So I think I may have two separate problems. Distributor cap and alternator. Years ago, when distributors were on top of the engine, I would just remove the cap and spray some WD-40 inside, plus inside where coil wire connected to the cap, and it would be good to go. Now the distributor is below the water pump, so I can't reach it to remove the cap. Oh, the blower fan just started to make a muted sound, as if it is plugged up with leaves or something. There were some leaves on top of the engine that I removed, but maybe some got sucked inside the blower? I do get air flow through. Are an alternator and distributor cap hard to replace? I just spent almost $1,000.00 on brake pads, rotors, and calipers, so I need to try to fix this these problems myself. Thanks for your help. Desperately Yours, Ted-

1 Reply

CARADIODOC

MECHANIC
33,727 POSTS

Hi Ted. Beginning in 1987, GM went from the world's second best generator to the world's worst pile. It is not uncommon to go through four to six of them in the life of the car. Besides charging issues, they can cause voltage spikes that confuse the dozens of computers on the car and cause running problems. This can happen even when they still recharge the battery properly.

One thing that is becoming more widely known among professionals is that to prevent repeat generator failures, it is necessary to replace the battery at the same time even though it still cranks the engine just fine.

When you buy a rebuilt generator, some mass merchandisers sell units that were simply repaired, cleaned, and tested. Intermittent problems might not be caught. The generators are extremely difficult to disassemble without destroying internal parts, so most rebuilders replace everything right away. The funny thing is, you can't go by price. You have to ask how it was rebuilt. One of my friends bought a third replacement for his Malibu and he found one with a one-year warranty for just under $200.00, and one with a lifetime warranty for about $70.00 less!

Caradiodoc