Felicia 1.3 MPi is cutting out and misfiring due to battery voltage drop - checked charging with multi-meter 13.98v however when applying load i.e. heaters, wipers, lights etc volts drop to 13.35 and less should alternator not cover this to maintain voltage?! is the alternator knackered as ive tried 3 different regulators?!?!?

Hi scirossco

If as you say the alternator is putting out 13.3 volts then that alone will not cause a problem, but it sounds like there is a bad connection to the ignition electrics.

Check all your connections to the coil etc,and also your earths, there could be a Alternator earth problem so its a hard job, but its just a matter of checking it all through.

Radiotwo

Edited 13 July, 200916 yr by DGW
Quote deleted. Members don't need to read the previous post again!

I thought that. 13.35 is maybe a bit low but it will still be charging.

checked the resistance between alternator main lead and battery positive which is 0 so no problem there however its not charging the car as it cuts out once battery is flat and wont start again till charged out with vehicle

The normal digital voltmeter ,reading very low cable resistance is not very accurate,With the leads shorted you get a reading up to about 0.7 ohm , which is lead resistance!.The correct way to read very low resistance (up to 1 ohm)accurately is with a 4 wire low reading ohmeter, meter current flows through 2 of the wires,and the voltage to be read (and converted to an ohm reading)through the other 2 wires.Such instruments are likely to be found in laboratories ,and universities, not garages.

A better way is to put your meter on the lowest DC millivolt range (usually 200 millivolt, which is 0.2volt), on either end of the cable .With no current flowing , no voltage will be shown.By putting various items (lights ,motors,etc) a reading will be obtained. I would not expect to get a reading of anything higher than 0.5 volt .This does not include the starter turning,or the alternator charging a flat battery, where larger currents are flowing.This method can also be used to check any ground (chassis) connections by reading from the battery negative terminal ,to the actual ground connection being checked.