Electrical Problems

[Tyral]

Hey guys recently put a S2 25DET in my S1 R33 and put the car back together after the previous bloke took it apart.

Anyway I took it out for a drive and she runs sweet but if I take the positive lead off of the battery while the car is running it shuts off, also the battery drains bloody quickly.

Any diagnosis? Cheers guys.

[koduRB25det]

why did u remove the + lead while car running. ? it is very bad idea... it can damage your serious elec components. hope nothing happened.

[Tyral]

O snap. A mate wanted to swap the batteries around and said "my car runs fine with the battery unplugged"... well then.

[mad082]

yeah as above, pull the lead off the battery isn't a good idea, however the car should still run without it on. i'd say that that symptom as well as your battery draining fast is probably a sign that your alternator isn't working properly. i'd get it checked (can do this yourself with a multimeter or have an auto electrician do it for you)

[Tyral]

Hey guys bit of an update, battery has 340CCA (+- a few) and measures 12V stationary, when the cars idling it measures 10.XXV - is this expected?

Mad are you able to give me any details on checking my alternator? I have a dmm.

Cheers for the help fellas.

Ehh also I was at BP putting air in the tyres while idling and it just randomly shut off but all electrics were still up. Cranked over first pop after that so I'm lost.

Edited August 14, 2011 by Tyral

[666DAN]

Shagged alternator

[Hanaldo]

Yehhh definitely sounds like a rooted alternator. But to make sure, put the positive lead of the multimeter on the output terminal of the alternator. You may find that you have a high level of resistance between your alternator and your battery which is preventing your battery from getting a good current. That would be a very high volt drop so I doubt it is the case, but it's easy enough to test so you may as well rule it out.

[Tyral]

Sweet I'll give it a look when I get the car back. Also when I was on the way to the tyre place the car started to jerk and then just cut out, wouldn't turn over after that for about 5mins.

But after the break it went sweet again? Bloody odd. I'm no auto elec (obviously haha) but I have a hunch it could be the positive terminal on the starter?

A friend was putting the top bolt from the gearbox on and arced the terminal to the chassis, or something to that effect. When I bought the motor the plastic cap on the lower harness for the start was broken off so perhaps it's arcing randomly.

Thanks for you input boys, you've been a great help.

[Tyral]

Alternator's dead. Got stranded for 2 hours on the motorway, good old whale of a car drew too much power from the AA guys' jumper pack to make the drive home.

I've got another RB25DET lying in the garage which I could pillage the alternator from, only trouble is that that motor has done 289,000K. Either that or a rebuild.