Notices
993 Forum 1995-1998
Sponsored by:
Sponsored by: DashLynx

Battery drain, alternator problem?

Thread Tools
 
Search this Thread
 
Old 02-25-2024, 09:05 PM
  #1  
JGuti
Intermediate
Thread Starter
 
JGuti's Avatar
 
Join Date: Sep 2023
Posts: 40
Received 13 Likes on 6 Posts
Default Battery drain, alternator problem?

I noticed slow starts which got worse until the battery died. Jumped it right up. Hooked up a battery tender. I have not done a parasitic draw test yet but got a voltage meter. I see that with everything on it is under 13v. Could this be a sign of the alternator going. I will check all the ground wiring since I see comments about it.
​​

Idle, no accessories



Side markers only

Headlights on

Headlights and fog light

Headlights, fog lights, radio on

Headlights, fog lights, radio and AC fan on high

Headlights, fog lights, radio, AC fan high and AC compressor running.

Last edited by JGuti; 02-25-2024 at 09:06 PM.
Old 02-25-2024, 10:06 PM
  #2  
Gbos1
Rennlist Member
 
Gbos1's Avatar
 
Join Date: Jan 2011
Location: United States
Posts: 3,563
Received 736 Likes on 522 Posts
Default

Check your battery cables for any corrosion.
The following users liked this post:
JGuti (02-26-2024)
Old 02-25-2024, 11:42 PM
  #3  
mike cap
Rennlist Member
 
mike cap's Avatar
 
Join Date: Jul 2002
Location: Upstate NY
Posts: 4,079
Received 338 Likes on 237 Posts
Default

Caveman opinion is those voltages look ok with those bus loads and at idle. Based on these idle voltages not an alternators issue.

How old is your battery?

Last edited by mike cap; 02-25-2024 at 11:47 PM.
The following users liked this post:
JGuti (02-26-2024)
Old 02-26-2024, 01:23 AM
  #4  
paranoidandroid
Racer
 
paranoidandroid's Avatar
 
Join Date: Nov 2020
Location: TX
Posts: 383
Received 86 Likes on 74 Posts
Default

Check the readings when the car is fully warm vs at cold start. Its possible that voltage regulator works when cold but not when its hot. That would mean the vr is failing. Clean the contacts as well. The fan sucks in tons of dust and the connections don't stay clean after a while.
The following users liked this post:
JGuti (02-26-2024)
Old 02-26-2024, 10:24 AM
  #5  
pp000830
RL Community Team
Rennlist Member
 
pp000830's Avatar
 
Join Date: Jul 2004
Location: Dallas, TX
Posts: 9,604
Received 1,452 Likes on 1,023 Posts
Default

Hi J,
Before looking too deeply for an expensive solution check your alternator belt, that it is not too loose. In my experience, a failed alternator never archives the required voltage regardless of load.
Andy
The following users liked this post:
JGuti (02-26-2024)
Old 02-26-2024, 08:17 PM
  #6  
JGuti
Intermediate
Thread Starter
 
JGuti's Avatar
 
Join Date: Sep 2023
Posts: 40
Received 13 Likes on 6 Posts
Default

Originally Posted by mike cap
Caveman opinion is those voltages look ok with those bus loads and at idle. Based on these idle voltages not an alternators issue.

How old is your battery?
New battery around September last year. Going to do some troubleshooting. Thanks for all the pointers.
The following users liked this post:
Gbos1 (02-26-2024)
Old 02-26-2024, 09:05 PM
  #7  
IainM
Rennlist Member
 
IainM's Avatar
 
Join Date: Jul 2012
Location: Santa Cruz, CA
Posts: 2,103
Received 301 Likes on 232 Posts
Default

Check the ground connection from starter to chassis
The following users liked this post:
pp000830 (02-27-2024)
Old 02-27-2024, 11:57 AM
  #8  
mike cap
Rennlist Member
 
mike cap's Avatar
 
Join Date: Jul 2002
Location: Upstate NY
Posts: 4,079
Received 338 Likes on 237 Posts
Default

I added a TopDon BT100 battery tester to my tool box a while ago. Handy addition and about $50 on Amazon. Used it on the 997 and found the battery was on its last legs after 8 years. May be worth purchasing.
The following users liked this post:
alsamrob4 (02-27-2024)



Quick Reply: Battery drain, alternator problem?



All times are GMT -3. The time now is 07:51 PM.