Well this is my first post, so hello to everyone. I’ve been reading the forums for ages though, and have found everyone to be really helpful, so perhaps someone can help me.
Basically my battery is draining overnight. I’m going to put everything below, so be prepared for a good read!
I have a 94 GPX tip, done about 96K, and just over a month ago I had a new Exide 550 battery installed, as well as a new Kenwood USB headunit and an immobiliser/alarm at Complete Car Sound in Brisbane. I was really happy with their work (The alarm is a Mongoose M80s). I also put in new headlight bulbs, narva’s on both hi’s an lo’s.
Everything was fine until last Sunday morning I find a soft constant beep coming from under the bonnet where the siren is. The battery is completely flat. I thought the alarm might have been trieggered and drained the battery. So I jumpstarted, but found that there just wasn’t enough to even have my rev counter function properly, so left it to charge overnight. (battery still connected)
I tried the next day and she started fine, went for a drive and after 5min decided to come back as the voltage kept dropping and the indicators were making the rev counter die. I’m thinking failed/failing alternator. So I disconnected the battery (which set off the alarm thanks to the battery back-up) and charged it up which charged quicker as well. Once charged I connected it back up and used a multi-meter to find the voltage dropping constantly even though nothing was on. It drops about 0.01 volts every 5 or so seconds, or about ½ a volt every hour. I figure if there is something wrong with the alternator, the car shouldn’t start? But she does start and with about 1000rpm the voltage is at about 13v and more with more revs.
So I started checking all the fuses. I also found that both my low beam lamp sockets have melted on one prong. (And I double checked the old ones were 60w, the new ones are 55w). So I removed these and checked for shorts and although the plastics melted it doesn’t seem like the prongs are touching. I also removed every fuse in both boxes. (except the alternator ones which are bolted in) - and the battery is still draining. In fact it seems faster. Disconnected the battery is fine, it only discharges when connected. So I might need to try remove the alternator fuse, but otherwise I’ve run out of ideas.
