Fuse blowing

[Pgxxl]

Hi , twice recently I have tried to start my car and the main fuse in line from the negative terminal has blown.could this be due to a low battery ?

[MarekH]

What fuse would this be?
There is no fuse in line with the negative terminal of the battery on a standard car. The negative terminal just connects to the chassis on a standard car. From there, it also connects to the engine block.

kind regards
Marek

[ALAN COCHRANE]

Hi

As Marek has said the standard car wiring setup does not have an inline fuse anywhere on the primary ignition circuit wiring.
If I were you I'd junk it as they're more trouble than they're worth as you're now finding out.
They don't adequately protect the primary ignition circuit and certainly do nothing for the secondary wiring.
I fitted them to both my Triumph and E-Type positive leads a while back, but have since binned them after the E's blew when I was trying to move the car on the starter motor. Luckily it was only in my driveway after the fuel pump had failed and not on a busy road!
The current draw when cranking is considerable-150A upwards depending on which starter motor your car has fitted. If it's the original then it's around to 50 years old and may draw varying levels of current during cranking depending on the state of the motor windings and the contact continuity of the solenoid operated switch.

[lowact]

Its even worse if battery is not fully charged. Power = volts x current. If Starter draws 150 amps when voltage is 12V, for the same power (starting requirement) it will need 200 amps if voltage is only 9V. Fuse is blown by high current. So yes, the issues caused by such a fuse would definitely be exacerbated by a low battery.

[cactusman]

Any fuse in the main starter circuit is next to pointless. Remove it....