Alternator please help!!!
No. Current surges are what you worry about when the power company turns the power back on and the voltage spikes.
If there were current surges in automobiles, they would blow the secondary fuses, such as the 5 amp, 7.5 amp and 15 amp fuses, not the fusible link.
Study up in series circuits my friend.
If there were current surges in automobiles, they would blow the secondary fuses, such as the 5 amp, 7.5 amp and 15 amp fuses, not the fusible link.
Study up in series circuits my friend.
Oh my,
There is a misstatement in one of my previous posts regarding the behavior of fusible links.
A fusible link of proper gauge with an excessive current load will burn through FASTER than a fuse can.
I had stated it would ramain intact for very short current spikes. That is incorrect
Your incorrect statement about current spikes taking out the rest of the fuses is incorrect because the fusible link will burn and cut off the current before it ever reaches the fuse box.
This is the reason for using them in this application
The rest of the electronic circuits never see the current spike once the link burns, so nothing past the fusible link is damaged.
Replacing a fusible link with a fuse essentially removes the higher level of protection provided by a fusible link and in theory increases the chance of the current spike getting to and damaging the fuse box and beyond.
There is a misstatement in one of my previous posts regarding the behavior of fusible links.
A fusible link of proper gauge with an excessive current load will burn through FASTER than a fuse can.
I had stated it would ramain intact for very short current spikes. That is incorrect
Your incorrect statement about current spikes taking out the rest of the fuses is incorrect because the fusible link will burn and cut off the current before it ever reaches the fuse box.
This is the reason for using them in this application
The rest of the electronic circuits never see the current spike once the link burns, so nothing past the fusible link is damaged.
Replacing a fusible link with a fuse essentially removes the higher level of protection provided by a fusible link and in theory increases the chance of the current spike getting to and damaging the fuse box and beyond.
Last edited by derf; Jun 1, 2025 at 08:54 PM.
Remember that you have a battery capable of delivering 550 cold cranking amps to everything connected to it. So the fusible link is of no value in preventing surge currents when your cooling fan goes on.
What would happen if you install a dead battery in your car after putting in a new alternator. You jump start your car and the alternator sees the dead battery as a dead short , and that dead battery is going to suck more current than the alternator can generate safely. The fusible link will blow and save the new alternator.
What happens if your alternator shorts out? The fusible link blows and saves an alternator fire or a battery cable fire.
As far as limiting current draw from circuits being switched on, it will be of no use since the battery is capable of supplying much more current than the alternator. Yes, the alternator runs at a higher voltage than the battery but a sudden demand for current will drop that voltage down to battery level. The battery will then be the main source of current. So the fusible link is mainly to prevent an alternator or starter cable from becoming a safety hazard.
What would happen if you install a dead battery in your car after putting in a new alternator. You jump start your car and the alternator sees the dead battery as a dead short , and that dead battery is going to suck more current than the alternator can generate safely. The fusible link will blow and save the new alternator.
What happens if your alternator shorts out? The fusible link blows and saves an alternator fire or a battery cable fire.
As far as limiting current draw from circuits being switched on, it will be of no use since the battery is capable of supplying much more current than the alternator. Yes, the alternator runs at a higher voltage than the battery but a sudden demand for current will drop that voltage down to battery level. The battery will then be the main source of current. So the fusible link is mainly to prevent an alternator or starter cable from becoming a safety hazard.
Last edited by cjenrick; Mar 7, 2025 at 11:31 PM.
Gotta wonder, if when you replaced the starter, that you got all the wires back on the correct terminals? Or if you pulled on the wire harness to hard and pulled some connector that later came apart. That could refer to the alternator as well, referring to the wire harness being pulled.
Check for 12 volts at the back of the alternator and the back of the starter both. If it's missing, then delve a little deeper into if it should be there. The starter should have it on the big terminal, and so should the alternater have it on the big terminal. Should be same voltage as the battery voltage on the positive terminal.
Check for 12 volts at the back of the alternator and the back of the starter both. If it's missing, then delve a little deeper into if it should be there. The starter should have it on the big terminal, and so should the alternater have it on the big terminal. Should be same voltage as the battery voltage on the positive terminal.
Last edited by PrestonIII; Jun 1, 2025 at 04:41 PM.
Thread
Thread Starter
Forum
Replies
Last Post



