Electrical Problem

Reply

  #1  
Old 08-21-03, 09:02 AM
Tommg
Visiting Guest
Posts: n/a
Electrical Problem

1985 Mazda RX7 GSL-SE 13B Fuel Injected engine.

A couple of days after having a radio installed, the car wouldn't start. It has a new battery and new starter. It seemed to have zero battery; didn't crank or click. The radio would turn on but there was not enough power to rotate the hidden hidlights. I jumped the car and it started right up, but wouldn't re-start. The dashboard voltage meter indicated 14 volts.

The following day, I was going to charge the battery, but first tested it with a voltage meter, and got the reading of 12.5 volts with the positive cable removed.

Suggestions? Thanks in advance!

Tom
 
Sponsored Links
  #2  
Old 08-21-03, 09:09 AM
Joe_F
Visiting Guest
Posts: n/a
Thumbs down

Sounds like a hokey radio installation. My guess is they hooked something up wrong and it's draining your battery.

Back to them and have them correct the problem for you. Failing that, do a charging system test as I have in my "The Basics" below.
 
  #3  
Old 08-21-03, 09:32 AM
Tommg
Visiting Guest
Posts: n/a
Another Question

Thanks, Joe!

Should I run the voltage test on the battery terminals after I get the car started? And then turn on accessories one at a time to test for fluctuations?

If I find the offending accessory, will there be a drop in voltage?

Thanks!

Tom
 
  #4  
Old 08-21-03, 10:00 AM
Joe_F
Visiting Guest
Posts: n/a
Charge the battery up (assuming the battery is good).

Then, do the test. Tell us what you find. Chances are if it's not putting out 13.5 volts or better, you have an alternator/charging system problem.

If it JUST occured recently after the stereo install, I'd be looking there first.
 
  #5  
Old 08-21-03, 10:41 AM
Tommg
Visiting Guest
Posts: n/a
If the battery tests 12.5 before charging, doesnt that indicate it doesnt need a charge?
 
  #6  
Old 08-21-03, 01:18 PM
Joe_F
Visiting Guest
Posts: n/a
Ya, 12.5 is good for a battery to start with.
 
  #7  
Old 08-21-03, 02:18 PM
Tommg
Visiting Guest
Posts: n/a
Resolution?

I reconnected the battery cable to run the voltage tests and it started right up. I am praying that this means that the lunitics who installed the stereo left the cable "almost" tight.

When running, the altenator put out 14.x volts and none of the accessories seemed to drain the voltage.

Thanks again for your help!!

Tom
 
  #8  
Old 08-21-03, 07:28 PM
billys68ss's Avatar
Member
Join Date: May 2003
Location: USA
Posts: 1,459
Thats what it sounds like. Get back to the radio shop and get them to hook it up properly. They tend to do that. It sounds like where ever they have it connected is definately draining the battery.

On a side note. 12.5+/- volts with a DVOM does not necessarily mean that the battery is good. The battery requires a certain level of AMPs to properly crank the engine over. ie CCA and CA, cold canking amps and cranking amps. Low amps would for the most part indicate a bad cell in the battery. Although I dont think this is your problem.
Hope this helps,
Billy
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes