Alternator heating up? Normal?
Thread Starter
Burning Brakes
Joined: May 2006
Posts: 763
Likes: 0
From: FBO Florida
Alternator heating up? Normal?
From a cold start my alternators case heats up pretty good after a few minutes from a cold start. Is this normal? I don't recall ever having checked it or noticed before. The alternator was just rebuilt.
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
it will warm up based on the load you put on it and how much it can carry. A 65amp unit will warm up more than a 140 amp unit in the same car. Now the real question, What is Warm? What are you running? Fans, big stereo, Halogen lights....
Thread Starter
Burning Brakes
Joined: May 2006
Posts: 763
Likes: 0
From: FBO Florida
Liek hot pavement- I'm guessing 125 degrees? Not running anything besides starting the car. The battery was dead previous to the start though. It is a 42 amp case. Who knows how it was rebuilt (ie more amps).
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
If the battery was dead, then the alt is trying really hard to 'Catch up' and charge the battery at full output. You can remedy this by charging the battery with a charger or tender, and then starting the car. The alt will likely not get as hot. Hot to the touch in normal, but if it burns you it's too hot and something may be wrong.
Le Mans Master
Joined: Feb 2004
Posts: 5,383
Likes: 11
From: Toronto Ontario
If the battery was dead, then the alt is trying really hard to 'Catch up' and charge the battery at full output. You can remedy this by charging the battery with a charger or tender, and then starting the car. The alt will likely not get as hot. Hot to the touch in normal, but if it burns you it's too hot and something may be wrong.
you just described what I went through this summer
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
Race Director
Joined: Sep 2001
Posts: 10,560
Likes: 439
From: Wellington, FL
St. Jude Donor '11 thru '25
Actually, you shouldn't use the alt. to charge the battery, although most do it. It is not designed for that purpose...only to top off the battery after minor discharges. At a minimum, it shortens its life.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Also, if you find your battery is always drained, you either have a bad alt, or need a bigger alt. Keeping a battery tender on the car when it's not being driven is the best way to make sure you always have a good charge.
Thread Starter
Burning Brakes
Joined: May 2006
Posts: 763
Likes: 0
From: FBO Florida
I haven't driven the car since I put the alternator back on it. I just started it, which is when I noticed the alternator heat. No it wasn't scalding but not cool either (my guess 125F). Tonight I'll put a 2 amp trickle charge on the battery. This way when I take it out of the batcave this weekend it won't be taxing my new alternator like you suggest. The (restoration) battery is less than 1 year old. I don't have any experience with the new restoration batteries which are sealed gel instead of acid liquid. The old resoration batteries had a very short life. I gave up on getting them for my other cars. They all run NAPA now.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Let us know how the alt does with a charged batter. A tender is the best way to keep that restoration battery good for a few years. If it sits for long periods of time with no use it'll go bad VERY fast.
