Alternator or 100 amp fuse?
Discussion
How do I know if it is the alterntor that has given up the ghost or if it's the 100 amp fuse that has blown?
Symptoms I think are similar from having searched previous posts.
I tried to get at the 100 amp fuse last night, but whilst I can see it and just reach it with my finger tips, I can't open the black box to get it out, and I don't have a trolley jack to lift the front end up.
If it helps at all the problem occured on Sunday. I'd been in a traffic jam (due to a crash) and turned on my fan override to stop overheating. When I set off, I think I forgot to turn this off, and switched it off (or maybe on again) whilst driving along. This was followed by an immediate loss of power, so I had to pull over, and the engine then died on me. The car wouldn't start again (I have also had the hot start problem). RAC man came out and diagnosed the alternator as the problem. Now the car is back in my garage, I've had the trickle charger on, and can start the car up, and keep it running, so long as I keep it above 2000rpm. If I let it go beneath 2000rpm, the engine dies (the red battery/alternator light comes on shortly before it dies).
Any guidance would be much appreciated.
Thanks,
Tom
Symptoms I think are similar from having searched previous posts.
I tried to get at the 100 amp fuse last night, but whilst I can see it and just reach it with my finger tips, I can't open the black box to get it out, and I don't have a trolley jack to lift the front end up.
If it helps at all the problem occured on Sunday. I'd been in a traffic jam (due to a crash) and turned on my fan override to stop overheating. When I set off, I think I forgot to turn this off, and switched it off (or maybe on again) whilst driving along. This was followed by an immediate loss of power, so I had to pull over, and the engine then died on me. The car wouldn't start again (I have also had the hot start problem). RAC man came out and diagnosed the alternator as the problem. Now the car is back in my garage, I've had the trickle charger on, and can start the car up, and keep it running, so long as I keep it above 2000rpm. If I let it go beneath 2000rpm, the engine dies (the red battery/alternator light comes on shortly before it dies).
Any guidance would be much appreciated.
Thanks,
Tom
Personally I'd change the fuse regardless. It costs pence and, from what I've read, is the problem 99% of the time.
They go very easily and can stop the battery from charging whilst still having enough of a connection to stop the warning light from coming on. If the car died and you didn't see the warning light come on then its probably the fuse.
They go very easily and can stop the battery from charging whilst still having enough of a connection to stop the warning light from coming on. If the car died and you didn't see the warning light come on then its probably the fuse.
I had the fuse go a week ago. I completely failed to notice the charge warning light was on (it's not very bright) and ended up with a flat battery.
Driving along and the car started to hesitate, the oil pressure went to near zero - scary moment!, and then it died. I replaced the battery as it was 7 years old and spent some time getting to the fuse - they don't make it easy do they? found it had blown, and bodged it
. The car goes in to Fernies next week for it's service so I will ask them to replace it.
I'm not sure this is any help, but good luck. I hope it turns out to be the cheap fuse rather than the alternative!
Driving along and the car started to hesitate, the oil pressure went to near zero - scary moment!, and then it died. I replaced the battery as it was 7 years old and spent some time getting to the fuse - they don't make it easy do they? found it had blown, and bodged it
. The car goes in to Fernies next week for it's service so I will ask them to replace it. I'm not sure this is any help, but good luck. I hope it turns out to be the cheap fuse rather than the alternative!
Has to be done from under the car. I managed to do it with the scissor jack and some axle stands (don't try it without stands or ramps!).
You may have to lift the car a bit with the scissor jack to get a trolley jack under.
If it's not the fuse, check/clean/tighten all the connections (including earths) before replacing the alternator.
You may have to lift the car a bit with the scissor jack to get a trolley jack under.
If it's not the fuse, check/clean/tighten all the connections (including earths) before replacing the alternator.
The fuse is between the starter "main supply" and the alternator. Like all fuses it should be near the start of the cable, so if the cable goes to chassis, or the alternator goes short, it will blow. Had mine go and no light came on, just the volt meter reading low, managed to get to my local dealer as he was closer than getting home and done FOC, well a beer for the mechanic.
Re location.. After much thinking (ouch) I decided that the system would be better done so:
Big red Starter cable to starter (as was)
Duplexed Brown cables changed
Starter pole to battery removed
Starter pole to alternator removed
(this is where the fuse commonly is, but I didnt have one)
New Battery to Fuse box (500mm instead of 3m!)
Starter pole - battery cables shortened & used for alternator to battery connection
Both have 100a fuses in footwell.
Seems to work well, and I reduced weight by 5m of 70a cable :-)
Dave
Big red Starter cable to starter (as was)
Duplexed Brown cables changed
Starter pole to battery removed
Starter pole to alternator removed
(this is where the fuse commonly is, but I didnt have one)
New Battery to Fuse box (500mm instead of 3m!)
Starter pole - battery cables shortened & used for alternator to battery connection
Both have 100a fuses in footwell.
Seems to work well, and I reduced weight by 5m of 70a cable :-)
Dave
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