Thanks Dennis.

I'll be curious to see exactly what the voltage is at the battery
w/engine running. Likely all is fine though.

Neil.

On Sun, Nov 22, 2009 at 5:25 AM, Dennis Haynes <d23haynes57@hotmail.com> wrote:
> Typically the ECU can handle 15-16 volts without immediate damage. There are
> regulated circuits inside but the injectors and some other stuff uses
> straight battery voltage. All VWs have the alternators running ~13.8 volts.
> This voltage is chosen as it gives a good compromise for battery charging as
> it is just at the edge of "gassing" the battery. Lower voltage leads to
> sulphation and incomplete charging. Higher voltages can lead to corrosion of
> the positive plates and excessive gassing during longer trips.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
> neil n
> Sent: Friday, November 20, 2009 4:33 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: How many volts can ECU handle?
>
> Hi all.
>
> Although I rebuilt the wiper linkages/shafts not long before swapping
> engines, (Jetta 2.0) and it may be that they are simply working as
> designed, my wipers have always seemed pretty "fast" since the engine
> swap. Like fast enough that putting them on high, is kinda scary! (I
> notice it more now as I tended to drive my Westy in Spring/Summer)
> This lead me to thinking: "maybe my alternator is putting out too many
> volts?"
>
> Seems to me that the principals of Jetta and WBX ECU's should be the
> same in this regard, so.....
>
> Looking at my Vanagon Bentley, I see B+ from alternator going to the
> Digifant control unit relay, then off to the Digifant ECU. Seems to me
> that the amount of volts to the Digifant ECU is controlled only by the
> alternator regulator. (or is there some other limiting component in
> the ECU relay?)
>
> More a point of curiosity than anything, but if an alternator puts out
> too many volts, would this do any damage to an ECU? I figure that
> things like wiper motors etc. can handle a little more, but was
> curious about a more sensitive item like the ECU.
>
> Either way, I should test alternator output.
>
> Neil.
>
> --
> Neil Nicholson '81 VanaJetta 2.0 "Jaco"
>
> http://tubaneil.googlepages.com/
>
> http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engine
> s
>
>

--
Neil Nicholson '81 VanaJetta 2.0 "Jaco"

http://tubaneil.googlepages.com/

http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines