Mazda Rotary Club

Cars by Model Type => 3rd generation RX-7's => Topic started by: jonny116 on December 16, 2008, 12:53:24 AM

Title: Damn, had to call the AA!!!
Post by: jonny116 on December 16, 2008, 12:53:24 AM
Battery died on me sunday morning, called the AA out and he said something on the alternator is not charging when iv got any electrics on.  Charges fine when nothing electrical is on...???  

Left it running for 20mins to get some charge in it but the battery light stayed on (fades off as you put foot down). I need to give it a full charge yet mind!


But then on my way home tonight at the last set of lights the engine suddenly drops to 4-500 rpm, sounded n felt really shakey... is this related??    

It turned off and then back on fine but still dropped back down to those really low revs, normally sits on 900 - 1k.
Title: Damn, had to call the AA!!!
Post by: steven_c on December 16, 2008, 06:15:58 AM
yeh something is draining the battery quite badley by the sounds of it, just check the battery itself and do a check on the alternator. either going to be one or the other car\'nt see it been anything else..
Title: Damn, had to call the AA!!!
Post by: shaunwil on December 16, 2008, 08:21:29 AM
Sounds like you could have lost part of the alternator, may only be charging a little bit into the system.

Shaun
Title: Damn, had to call the AA!!!
Post by: ash on December 16, 2008, 10:55:00 AM
Get hold of a voltmeter, run the car leave it to idle, then with the voltmeter set to .20 read across both terminals. The reading should be 14v or near. This will indicate if the alternator is charging.
Title: Damn, had to call the AA!!!
Post by: jonny116 on December 16, 2008, 01:08:26 PM
strange, is 14v when idle but if anything electrical is on i.e. lights, heater or sterio it drops to 12v.  
 
Am thinking new alternator?  Or new battery?
Title: Damn, had to call the AA!!!
Post by: Will66 on December 16, 2008, 01:12:29 PM
Sounds like the alternator might be dead.  It\'s not producing enough volts to supply the lights or anything else and keep the battery charged.  If you\'ve discharged the battery you might as well replace both.
Title: Damn, had to call the AA!!!
Post by: ash on December 16, 2008, 05:17:21 PM
14 v can be with stereo on, lights on dipped, small electrical etc. Try it and u will know for sure if the alt. has gone. also just check the connections are tight.
Title: Damn, had to call the AA!!!
Post by: m1tch on December 16, 2008, 09:16:35 PM
Are there any short circuits behind the stereo? I know I had this issue I while back on my other car, there was a short circuit behind the stereo meaning that it was draining the battery.
Title: Damn, had to call the AA!!!
Post by: neil_jdmr on December 19, 2008, 12:18:39 PM
Yup ill second this, Its either a short on one particular circuit pulling the voltage down or your alternator is goosed.
Title: Damn, had to call the AA!!!
Post by: neil97rs on December 20, 2008, 10:30:12 PM
alternator most definataly needs to be putting in around 14v with everything on
Had the same thing a couple of weeks ago llight kept going out with higher revs but it died completly after a couple of weeks
Title: Damn, had to call the AA!!!
Post by: Bobbit on December 20, 2008, 10:43:05 PM
Jonny\'s had it fixed, was the alternator.
Title: Damn, had to call the AA!!!
Post by: jonny116 on December 22, 2008, 09:20:27 AM
Yep had it fixed, is still giving me really low revs but think it may be the spark plugs?  
 
Splutters on and hovers around the 600 mark, feels like it almost misfires upto 1400 revs n then is fine.  
 
haha, Rob how did you know i had it fixed?
Title: Damn, had to call the AA!!!
Post by: Bobbit on December 22, 2008, 10:55:03 PM
I popped in to see Jurgen on sat bud, was gonna get him to lift me car up on the ramp to check the exhaust but ran out of time from chatting too much, lol.
When did you last change the sparks bud?
Title: Damn, had to call the AA!!!
Post by: jonny116 on December 23, 2008, 09:24:16 AM
ahh right, i was in there just after 2.00, must have just missed me!  
 
Don\'t know when the spark plugs have been changed and it only happened after i\'d floored it.
 
Am thinking one of them has totally gone with the way the engine is sounding.  Chugging like a diesel and running rich so sounds definetly the plugs... I think?!?!