I bought a nice 308 replica last week. The car had been stood for a while and had a dead battery. It jumped fine off a new battery, but the old battery wouldn't hold charge. On the drive back, the volt meter showed between 12 and 13 on the gauge with the new battery connected in parallel. I fitted a new battery now and the car bursts into life but the volt gauge shows just above red. With the engine running and a volt meter across the battery terminals shows 12 v with no pick up when revved. After reading a few posts it looks like the alternator is at fault but could i also have disturbed something around the battery area when changing the battery? On the 308 replica swapping the battery is hard as there is not much space. Thanks Ian
Thanks for the reply. I have investigated further and have found a problem. There was a very poor crimped connection between the big red cable with a fusible link that comes from the engine loom to the main engine wiring block - called c500 i think When I wiggled this, lots of sparks followed and actually set fire to the tinder dry engine sound deadening! I disconnected the battery(!) and installed a new link but upon reconnecting the battery the new link began to melt.... Looking at the wiring diagram, the wiring looked correct. I.e, From the battery , a large red cable runs to the engine block harness, from which another big red cable then runs to the alternator via the fusible link. Correct? So why do i have an short circuit? Would a grounded alternator cause this fault? Thanks Ian
[This message has been edited by Drfiero308 (edited 12-22-2013).]
Originally posted by Drfiero308: Would a grounded alternator cause this fault?
Ian, all alternators are grounded. The ground path is the external aluminum case of the alternator, the ground path is completed to the block through the alternator brackets and bolts.
Doh! But clearly i have a short somewhere as this happens when i connect the alternator red cable to the connector block.... This image from a great v6 removal thread shows the large red cable joining the connector block, which if i do this on mine, as it was, until i disturbed something, now creates a short?
Hmm edit... Been reading more and alternator wiring should always be live/hot so something else seems wrong. In my earlier attempt to replace the bad connection,i wired in some 27 amp rated wiring and this melted. Am i correct in that the alternator is faulty and is directly grounding the battery and the fuse link worked by melting and so did my replacement?
[This message has been edited by Drfiero308 (edited 12-22-2013).]
I got a little lost on your OP but I am assuming the battery is connected correctly. When you replaced the wiring that was sparking, did you also install the correct fusible link?? I am also wondering if the insulation on the wire is damaged and grounding on surrounding metal.
Check out the Ogre's Cave (link at the bottom of every page), there is a LOT of good information there about the charging system on a Fiero.
Thanks for the reply. Just fired up the car and started first time as usual but no voltage on the alternator feed to the battery. Also i have continuity between the alternator output and earth, which i think looking at wiring diagrams is wrong. Looks like the alternator is dead? Ian
You're probably on the right track with rearranged wiring, but it's hard to see how it ran at all if you can't even hook it up. I had a no charge situation which was simply the alternator was unplugged. There is a plug on the bottom of the alternator. Plugged it back in and taped the loose connector in place. Since then it has run fine, except it overcharges at high speeds, like 16 volts at 60 mph. Anyway, worth checking.
I don't know how much $$ you want to throw at the problem but if I were you I would just get a new alternator (or at the least get the current one rebuilt) and re-wire the main alternator wire with a new fusible link. Alternators are fairly cheap in comparison to a burnt up 308 replica When I was having a battery drain on my 87 GT I narrowed down the problem to that main alternator wire. Instead of inspecting and trying to fix the near 30 year old wire, I just bought about 4 feet of heavy gauge wire and a few other misc parts and re-ran the wire. This way I know that it is new and will not give me problems for a very long time.
Yes i have piked up a new alternator and will look at the cable over the festive period. But can someone clarify IF the alt/battery light needs to be working for the system to charge? I have read different views on this.... Ian
When I was having a battery drain on my 87 GT I narrowed down the problem to that main alternator wire. Instead of inspecting and trying to fix the near 30 year old wire, I just bought about 4 feet of heavy gauge wire and a few other misc parts and re-ran the wire. This way I know that it is new and will not give me problems for a very long time.
