Alfa Pages

[Chris]

Hi guys.

I drive the alfa for 45 minutes, turn it off, then attempt to start it again, the motor turns over extremely slowly (sounding as if the battery is flat) - resulting in that I cannot start the car. When the car is cold it does start ok.

(Hehe, no more quick trips down to the shop for the wife - car won't start )

I have checked the battery voltage and the alternator charging voltage - they are ok.

I have to add that the car has been standing for 1 year in a garage.

Any hints/tips on what to look for?
What could effect the motor turnover on a warm engine?

Thanks all,

Chris (South Africa)

[rjbevan]

I would check the earth straps to the engine. Sounds like a high resistance joint somewhere.

Richard

[Chris]

Thanks, it appears as if that did the trick. (Reseated the bolt going through the starter motor/engine block)

Another question:
Disconnected the battery. I disconnected and measured the resistance from the negative wire connected to the starter motor (going to ignition switch) to the negative battery terminal and get 5 ohms when I turn the key as if to start the car. Is this acceptable?

Chris

[rjbevan]

Hi Chris, my first thought is that 5 ohms is too high, but you will be measuring the circuit with a low current and therefore could measure a higher than normal resitance across the contacts. The starter motor will have a low value of resistance so the starting current is high (greater than 50 Amps) so the power contacts on the starter motor can get damaged due to the current arcs, hence the high resistance when you measure with an ohmeter. To be sure you need to measure the voltage at the starter motor with it in circuit. Not too sure how easy this would be as I have never actually done it myself.

Richard