Djaniero Posted May 17, 2014 Share Posted May 17, 2014 Bit of a weird one guys for the electricians in the house. Basically I jump started my car a few months back, and connected the jump leads the wrong way around ...School boy error I know. Anyway, it blew the 80amp fuse and I had no power whatsoever in the car. I bought a new fuse, fitted it and all was fine.The car has been parked up for a few months since then, so I haven't really driven it until today. My oem double din radio wasn't working so I took it round to my mates- who is an electrician - to have a look. He traced the issue to be a bad earth. Then on closer inspection, he noticed that there was no earth on the radio, or the interior lights. We then checked the fuse box in the bonnet, and my 80amp fuse had started to melt at some point :s We also checked the battery with a voltmeter, and it was reading 15v @ idle, and went slight higher when the revs were increased, which my mate said was too high? So just to summarise: 1. I have no earth on the radio, or interior lights - Light isnt working and radio only works when we use an alternate earth.2. My 80amp alternator fuse has started to melt - still working.3. I'm getting a 15v plus reading on idle. Could this be an alternator issue i.e. is it over charging? Could I have damaged it in some way when I connected the jump leads up wrong. Apologies for the long ass post. But I just wonna get my car back on the road asap. Thanks Quote Link to post Share on other sites
turbo Grant Posted May 18, 2014 Share Posted May 18, 2014 The interior light eaths itself on one of the fixing bolts. Then the 2 wires in are both live for door and on position. And the radio should have a light grey/ white wire with a black stripe on for earth. I suspect you have fried the internal volt regulator on the altornator when you jump started the car. Quote Link to post Share on other sites
Djaniero Posted May 18, 2014 Author Share Posted May 18, 2014 Sorry i mean i have earths attached, but the interior light doesnt work, and the radio only worked when we moved the earth cable and attached it to a different location.So i ll need to replace the alternator then? Quote Link to post Share on other sites
turbo Grant Posted May 18, 2014 Share Posted May 18, 2014 For the charging fault replace the alternator. Does your cigar lighter and your heater control lights and stuff like that work? They usually run off the same earth inside the car. Quote Link to post Share on other sites
Djaniero Posted May 18, 2014 Author Share Posted May 18, 2014 Ok, I'll get on the case and find one. Do I need to get one specifically for my car? Its a 1994 GT? The heater controls still work, but I've not tried the cig lighter yet. The only other thing that is a little strange is, when I turn my lights on, the boost gauge and clock go mega dim.Lights off they go mega bright. Again, my mate said it maybe down to a bad earth? Quote Link to post Share on other sites
turbo Grant Posted May 19, 2014 Share Posted May 19, 2014 You could get an alt from any 4e / 5e really. As long as the plug on the back is the same shape. With the clock and boost gauge going dim that's normal. It's so they don't dazzle you at night Quote Link to post Share on other sites
Djaniero Posted May 19, 2014 Author Share Posted May 19, 2014 I'm waiting for pics from another member who has one for sale at the moment. Have you got a pic of what the plug will look like on one for my GT? Also how do you remove the laternator - Never done one before, but more than willing to have a go. ps - would it be worth just replacing the voltage reg in the alternator, or just get a different alternator? Thanks Quote Link to post Share on other sites
JayJ Posted May 21, 2014 Share Posted May 21, 2014 I just replaced my alternator. It's a tight fit, but quite easy to do from the below. Just remove top and bottom bolts, unplug connector and battery wire(10mm nut) and twist the alternator off between steering rack and drive shaft. After changing the alternator I got another problem though, refurbed alternator whines/whistle quite bad. It's not the belt or bearing but the electrical pitch whine going up and down with revs. I'm not sure if the alternator is bad or if my battery is also defective and alternator has to work harder causing whine. :-/ Quote Link to post Share on other sites
Djaniero Posted May 21, 2014 Author Share Posted May 21, 2014 Thanks a lot for this man. I'm gonna be changing mine this weekend hopefully, and didn't know the first place start - Only recently started doing DIY on my cars lol. Hmm, have you checked the voltage you're getting since fitting the new alternator? Quote Link to post Share on other sites
JayJ Posted May 21, 2014 Share Posted May 21, 2014 around 14v on battery terminals when charging, I think it should be ~14.4v but the difference is minimal and my battery is in boot, so there might be some difference. Also noticed this morning that battery volts seems to drop during night, but I have to check it today. Quote Link to post Share on other sites
Djaniero Posted May 21, 2014 Author Share Posted May 21, 2014 (edited) 14-14.4v is about right if I remember correctly. Keep me posted and let me know, if you find out what is causing the fault. Edited May 21, 2014 by Djaniero Quote Link to post Share on other sites
JayJ Posted May 22, 2014 Share Posted May 22, 2014 Small update, alternator is giving nice 14.5v out. Checked the battery yesterday and this morning and it was 12.3v meaning only ~60% load Quote Link to post Share on other sites
Djaniero Posted May 22, 2014 Author Share Posted May 22, 2014 So it was the battery that was at fault? Glad you managed to get it sorted man Quote Link to post Share on other sites
JayJ Posted May 23, 2014 Share Posted May 23, 2014 Battery might have seen the better days, but doesn't explain the sound. I think I have to change the alternator again as I put a pipe on it yesterday and listened to it. Sounds like a bearing or coil problem :-/ Quote Link to post Share on other sites
Djaniero Posted May 23, 2014 Author Share Posted May 23, 2014 Gutted . How many miles has the new alternator done do you know? Quote Link to post Share on other sites
JayJ Posted May 23, 2014 Share Posted May 23, 2014 It's refurbed one, I changed it last sunday and problem was there from the start. 500km now Quote Link to post Share on other sites
Djaniero Posted May 23, 2014 Author Share Posted May 23, 2014 Can you not take it back if its faulty? Quote Link to post Share on other sites
JayJ Posted May 23, 2014 Share Posted May 23, 2014 Yes I can it's under the warranty. Only problem is that I need the car, so I have to ask them if they can give me a replacement before I give the broken one back. Quote Link to post Share on other sites
JayJ Posted May 23, 2014 Share Posted May 23, 2014 Alternator changed again, this time successfully. Now I have to recharge my battery full and check if it holds the volts as it should Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.