Alternator issue? Maybe?

rick82 · Post by **rick82** » Fri Mar 18, 2016 8:00 am

when I first start the engine the the battery will read around the 14v mark, which is normal. After the engine settles the voltage will start to drop right down to 9v. No battery light but the dash lights dim, Rev counter drops off and radio switches off. Revving the engine will raise the voltage slightly but not to 14v.

I would say it's the alternator but the fact it does put the propper charge when I start makes me think it could be something else causing it? I know there are plenty of information on testing alternator but I was thinking I could just disconnect everything from the alternator, run the engine with just the battery and see what output it has without anything else possibly affecting the voltage out.

I don't really want to spend 200 on a new one when I'm not entirely sure it's that. Possible wiring issue?

Post by **RattyMcClelland** » Fri Mar 18, 2016 8:38 am

Voltage regulator in the alt.

preludemanh22 · Post by **preludemanh22** » Fri Mar 18, 2016 12:59 pm

I've got a next to new blueprint one here I've mailed u

Post by **vanzep** » Tue Apr 05, 2016 2:32 pm

would this be the same issue i have?
revs drop and there is a slow bounce between 400rpm-700rpm - only when i switch on the aircon once its up to temp
if i give it a little blip on throttle it settles back to a steady idle

it can also idle on the low side when going for a hot restart-again thats sorted by a blip on the throttle
ive change the main relay today and thats not fixed it so now looking at alternator and possible sticking accelerator cable.

just wondered what you guys thought

apologies for hijacking this thread

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Tue Apr 05, 2016 10:05 pm

What is the idle speed on the car set to?

Post by **Merlin** » Wed Apr 06, 2016 9:14 am

wurlycorner wrote:idle speed on the car s

What the car is idling at or its base idle (ie with the IACV disconnected)?

Post by **vanzep** » Wed Apr 06, 2016 10:16 am

will find out the base idle today
just wondering if something is sticking a bit - when i bought the car the accelerator cable was wrongly routed - so i put it in its correct position and adjusted it to take up the slack

fast idle is around 1400/1600 on start up
normal idle is 700-750
so all seems good but it has the dip in rpm when aircon switched on - or sometimes when on a hot start
its not a massive issue tbh but you how fussy i am

Post by **Merlin** » Wed Apr 06, 2016 10:19 am

The dip in idle count be a bad ELD (electronic load detector)?

Post by **vanzep** » Wed Apr 06, 2016 10:22 am

hmm where is the ELD

im guessing the alternator

will find the base idle / clean the IM and report back

Post by **vanzep** » Wed Apr 06, 2016 10:30 am

found this post about ELD from 2013

http://www.ludegeneration.co.uk/post148 ... ld#p148860

ELD is built into under bonnet fuse box ( i have a spare so no worry if it is that)
but will check alternator and iacv first