Help Me Fix My Electrics

[PranK]

Hey Guys,

Hopefully you guys can help me fix the electrics in my mk4 golf.

Basically, the worst problem is that when lots of stuff is on (high beams, wipers, stereo) and you turn on the indicator, the radio will sometimes turn off. Its super intermittent. If I watch my volts while driving, they can get as low as 11v which seems ridiculously low. The battery has never struggled to start the car, even when its been left for a week or so, so I dont think its that and when the indicators are on, they make the headlights dim.

I reckon its the alternator because of the drop in voltage when things are running.

What do you guys think? What and how can I test my theories?

Thanks!

Christian

[itshimdazza]

Hey Guys,

Hopefully you guys can help me fix the electrics in my mk4 golf.

Basically, the worst problem is that when lots of stuff is on (high beams, wipers, stereo) and you turn on the indicator, the radio will sometimes turn off. Its super intermittent. If I watch my volts while driving, they can get as low as 11v which seems ridiculously low. The battery has never struggled to start the car, even when its been left for a week or so, so I dont think its that and when the indicators are on, they make the headlights dim.

I reckon its the alternator because of the drop in voltage when things are running.

What do you guys think? What and how can I test my theories?

Thanks!

Easiest way to check in put a multimenter across your battery terminal and measure the voltage... should be above 13-14vols if not your alternator is going

Dazza

Christian

[PranK]

Hey mate,

I did do that and it was 14v but not under load. I should try again with everything on, eh?

[blind_elk]

Have you checked the fan belt tension?

[PranK]

Have you checked the fan belt tension?

I have not. Good call.

Should replace if its too loose, right?

[blind_elk]

Should replace if its too loose, right?

Up to you, really. It will be a judgement call depending on its condition.

[toddlls]

There was something like this on a cable show Wheeler Dealers prank, german cars had issue with relays behind dash I think- try voltage tester on stereo cables & wiggle wires-hope it helps mate

[blk94r33]

Alternator sounds like the culprit, or main wiring (ie earth, b+ to the alternator)

Check your earths too as they can cause funny electrical problems like this too. Best bet is with a multimeter measure voltage from your negative battery terminal to the various body earths on the car with all the accessories turned on. Anything over 0.2 volts can cause grief especially under load.

[tridentt150v]

I opt for dirty terminals on the battery or a bad earth, your voltage is dropping when you load it up. Could also be a bad cell in your battery failing under load, can happen!!

[PranK]

Sweet - thanks guys, will check all of these. I definitely didnt check the body earths when i was looking the other day.

Thanks!