Electrical Problems

[Graham Sewell]

OK, so these questions are mainly as a sanity check....

 

Two problems started over the weekend that may or may not be related. Firstly, the ignition light started to glow above idle speeds, but I did not notice any dimming of the headlights as the car slowed in traffic. Historically, I re-routed the wiring to the alternator a couple of weeks ago and forgot to disconnect the battery (!) and accidentally short circuited one of the terminals on the back of the alternator and got a mid sized spark. So I'm guessing that either the diode pack is shafted (probably not) or the light feed has blown. Are these easy to repair - or should I just get a new alternator?

 

The second problem came when I tried to restart the car later. I can hear the solenoid click and then the headlights don't just dim, they go out completely while the starter doesn't move. I tried a jump start from a second battery just in case the alternator was junk and the battery had gone flat on the way home, but no difference. Again, points to the alternator working properly (except ignition light feed).

 

Any ideas - or do I just replace both?

 

Cheers,

 

Graham

[Blatman]

You've fried the diode pack/regulator/rectifier. Same thing happens on my motorbike. As soon as you load the electrics up above idle, the warning light glows, 'cos the voltage is slowly dropping as load increases..........

[elie boone]

Graham,If the second battery is in an other car then you have to rev that car to +/- 3000rpm for a couple of minutes so that your flat battery has time to recover.

Otherwise put the jump leads direct on the starter motor.