'87 C4 alternator problems
Thread Starter
Heel & Toe
Joined: Jan 2013
Posts: 17
Likes: 0
'87 C4 alternator problems
Who has replaced their alternator on an early C4 and has never had any problems with it ever sense? My alternator died for the first time about 3,000 miles ago. Very luckily, the local O'Riley's just happened to have a 1987 Corvette alternator lying around. (I was out of town, hundreds of miles away from home, it died late on a Saturday night and I needed to get the car fixed and back in town for work on Monday!) So the new alternator (which was a rebuilt alternator supplied by whoever the manufacturer was, I forget) worked like a charm... for about 1,100 miles. Then the voltage started reading battery voltage all the time. So I got a new rebuilt alternator under warranty, and it's worked fine. I replaced it in winter. Now that it's summer, I observe that if the car is in drive, and at a stop with the A/C running, voltage fairly consistently goes down to 11.5-12.5 until I either start moving or turn off the A/C or put it in park.
I'm thinking I'm going to pop for a higher output capacity, non-rebuilt alternator cuz I'm sick of the hassle of replacing the alternator. Any recommendations what brand or model?
I'm thinking I'm going to pop for a higher output capacity, non-rebuilt alternator cuz I'm sick of the hassle of replacing the alternator. Any recommendations what brand or model?
Safety Car
Joined: Jan 2004
Posts: 3,783
Likes: 15
From: Northern California
I bought a 95 ZR-1 140 amp alternator which uses the larger CS-144 case from Rock Auto and it's been fine for the past 10 years!...
I did have to fabricate a new lower mounting brace and shave about an 1/8" from the alternator upper bracket but, they were very easy mods to do.
.
I did have to fabricate a new lower mounting brace and shave about an 1/8" from the alternator upper bracket but, they were very easy mods to do.
.
Last edited by GKK; May 15, 2014 at 06:06 PM.
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
1 - There aren't any new alternators for old C4s.
2 - Any other brand won't fit.
You're stuck with Delco, though you can find higher output units.
Make sure you get the correct number of grooves in the pulley -- I got one that had one too few. Also watch out for "clocking", which is where the connector is located. One more: the style of connector changed (I'm not sure when), so you need one that is compatible with your wiring.
Check out these guys:
http://alternatorparts.com
Team Owner
Joined: Sep 2003
Posts: 25,373
Likes: 2,734
I would consider having your electrical system load tested before I went to the expense of another alternator purchase. If the correct alternator was installed this past time I'd be inclined to let the parts house replace it "one more time" if indeed it's an alternator issue. I'm not talking about a "bench test" of the alternator but an on the car evaluation.
Some vendors have a premium line of alternators, maybe the parts house would substitute a premium one since you potentially have another.
Are you doing the installs or are you paying a shop?
Some vendors have a premium line of alternators, maybe the parts house would substitute a premium one since you potentially have another.
Are you doing the installs or are you paying a shop?
Race Director
Joined: Sep 2003
Posts: 16,836
Likes: 337
From: Database Error Indiana
After I modded my L98, I took it to 6000 rpm the first time my rebuilt from Advanced Auto it died. They replaced it free. Within 30 minutes that blew apart internally. I went to Autozone. They sell a NEW, not rebuilt one. That was several years ago. Seen well over 6ooo RPM 100s of times. Its a good alternator.
Team Owner
Joined: Sep 2003
Posts: 25,373
Likes: 2,734
If in fact you want to opt for something with a greater output consider the change to the CS144. There should be threads (many) covering the required connector and the changes required. Regardless I'd say have the present system "load tested" but if you insisted on a replacement the CS144 would certainly be to your advantage.
Racer
Joined: May 2012
Posts: 269
Likes: 0
[QUOTE=Cliff Harris;1586902688]A few problems with your scenario and your solution:
1 - There aren't any new alternators for old C4s.
2 - Any other brand won't fit.
You're stuck with Delco, though you can find higher output units.
Make sure you get the correct number of grooves in the pulley -- I got one that had one too few. Also watch out for "clocking", which is where the connector is located. One more: the style of connector changed (I'm not sure when), so you need one that is compatible with your wiring.
Check out these guys:
I would check out autozone, I got a "new"one, built in Mexico. Had nothing but trouble with rebuilds.
1 - There aren't any new alternators for old C4s.
2 - Any other brand won't fit.
You're stuck with Delco, though you can find higher output units.
Make sure you get the correct number of grooves in the pulley -- I got one that had one too few. Also watch out for "clocking", which is where the connector is located. One more: the style of connector changed (I'm not sure when), so you need one that is compatible with your wiring.
Check out these guys:
I would check out autozone, I got a "new"one, built in Mexico. Had nothing but trouble with rebuilds.
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Team Owner
Joined: Dec 1999
Posts: 34,873
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From: Lacey WA RVN 68-69
NCM Sinkhole Donor
You might want to look for a shop that specializes in rebuilding alternators and starters. Some of these businesses are run by people that have had many years of experience in that trade and will be able to build a unit that won't break down. In most cases, they can also upgrade an alternator to generate more power if it's needed.
But I also agree that you should have the charging system tested by a reputable auto repair shop. This testing will include a battery load test to make sure the battery is in good condition. The OEM alternator for the '87 is designed to handle the load requirements of the car so unless you have additional electrical requirements (audio system, plug-in devices, etc.) you really shouldn't need any higher output capacity.
In any event, I would not even think of buying the cheap reman or rebuilt alternators from the chain parts stores. In our shop we typically provide AC Delco, Motorcraft, Nippon Denso and Bosch alternators. While they are remanufactured units, the "professional-grade" units will have almost all new components installed and the testing will be more complete.
But I also agree that you should have the charging system tested by a reputable auto repair shop. This testing will include a battery load test to make sure the battery is in good condition. The OEM alternator for the '87 is designed to handle the load requirements of the car so unless you have additional electrical requirements (audio system, plug-in devices, etc.) you really shouldn't need any higher output capacity.
In any event, I would not even think of buying the cheap reman or rebuilt alternators from the chain parts stores. In our shop we typically provide AC Delco, Motorcraft, Nippon Denso and Bosch alternators. While they are remanufactured units, the "professional-grade" units will have almost all new components installed and the testing will be more complete.