Engine stall under heavy electrical load : where to look ?

[S P SHERMAN]

I'd start by checking the alt output.  Easy with a voltmeter at the battery. Check voltage on the battery terminals with the engine at idle and no load, then add load, then up the rpm.  Should be able to maintain a fairly constant voltage, say around 14v. If it drops alot as you add loads and does not recover as you up the rpms, the alt is not producing power or not enough power. For an even better picture, get a high capacity amp meter in line to the battery while doing this test. That will let you know how much current your alternator is putting into the battery (if any) with the loads on line. 
 
For an even easier test go to one of the auto big box stores. They will test the electrical system with a load for free. Although it won't tell you a whole lot more than this simple test (other than maybe whether its your battery or alternator at fault). 
 

> From: laraa at sympatico.ca
> To: urq at audifans.com; quattro at audifans.com
> Subject: Engine stall under heavy electrical load : where to look ?
> Date: Tue, 27 Mar 2012 16:47:38 -0400
> CC: geraint.lloyd.geo at gmail.com; eric at lefrancois.ca; denisjoncas at hotmail.com; info at dynodoc.ca
> 
> Hi everyone,
> 
> 
> 
> My good friend Eric has a few issues with its 20V 034-EFIed urQ. 
> 
> 
> 
> The most annoying is the fact that the car dies when the cooling fan starts,
> especially if the headlights are switched on. Brady tried to raise the idle
> speed or enrich mixture a bit, but nothing works. Now, Eric (who is a
> prominent auto journalist) wrote that he's thinking of selling the beast.
> For those who can read French (there is a nice picture of the car) :
> <http://auto.cyberpresse.ca/opinions/eric-lefrancois/201203/26/01-4509369-ma
> -quattro-toute-histoire-a-une-fin.php>
> http://auto.cyberpresse.ca/opinions/eric-lefrancois/201203/26/01-4509369-ma-
> quattro-toute-histoire-a-une-fin.php
> 
> 
> 
> I was there with them last Friday, and I noticed a few things : fan starts
> on the highest speed only, and very often for a short period of time. Could
> it be only that ?
> 
> 
> 
> This engine has a lightened flywheel : could it be "too" light ?
> 
> 
> 
> Many readers suggested bad engine grounds : but if it was the case, then
> how the hell the starter would get it's juice ? 
> 
> 
> 
> Let me know, and please reply to all so we can collectively cure this
> almost-sorted car.
> 
> 
> 
> We don't need another car to leave the nest.
> 
> 
> 
> Louis-Alain 
> 
> 
> 
> 
> 
> 
> 
> 
> 
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