Date: Sat, 18 Sep 2010 13:07:15 -0700
Reply-To: neil n <musomuso@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: neil n <musomuso@GMAIL.COM>
Subject: Re: Update and question inline VW Van block swap (in progress)
In-Reply-To: <AANLkTimSKKu9VToDdQAqEuJagAu4PNH4fUSK3hj2omjQ@mail.gmail.com>
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On Sat, Sep 18, 2010 at 11:19 AM, Don Hanson <dhanson928@gmail.com> wrote:
> Here's the relevant information: 84 Vanagon with (formerly) a 1.8 liter
> Cabriolet inline four motor ('92m.y. I was told) Digifant operating
> system. I replaced the lower end with an ABA 2.0 Jetta motor 93m.y. but
> kept all the head and everything else from the older 1.8liter. ....
> Now I get "backwards"
> behavior from before from my idiot light on the dash..
> .No light up when the key is on but not started. (The other indicator
> lights behave as before...Alternator and O2 sensor on, then off after start
> and a little increase in RPM. The oil pressure warning light,
> however...stays dark with key on-- motor off.)...then it lights up
> (flickering sometimes) when the motor starts and gets brighter as RPM (and I
> assume oil pressure) increases....I have some 10w oil in there right now as
> a peliminary wash-out oil so it is pretty light. Ok so when the motor is
> really hot and idles down low....the light flickers OFF....Like when the oil
> pressure is low, the warning light goes OFF and when it's high, the warning
> light comes on. Wassup with that?
>
> I have a no dynamic oil pressure gauge system...just that idiot light..I
> have tried plugging the sender wire (from the main harness up to the dash
> light) right onto the spade connector on top of the oil filter flange....I
> have also tried putting that wire onto a spade connector that comes from the
> front of the motor's head...and I have tried connecting both of those spade
> terminals to the instrument light plug at the same time...It is just
> backwards. Light bright when oil pressure is high/light off when OP is
> low..is there a way to reverse the action of the lamp?
>
> I plan on testing my oil pressure with a real gauge soon as I get to it,
> but until then, I would like to have a functioning warning system. Should I
> just take the filter housing mount off my old 1.8 liter block and use that?
> That seems reasonable but I think I will eventually hook up some plumbing to
> the little heat exchanger at the oil filter and get that working ...so if I
> can just swap some wires or change polarity or some "electrical thing" that
> would be good...
>
Your '84 has a 5 spd? Was it a diesel? VAGCAT online shows the '84
diesel having a dynamic oil pressure unit in inst. cluster. But as you
say, it's not present. Sounds like you only want one oil pressure
switch connected to the stock idiot light so.....
Sounds like you have the high and low pressure switch on your ABA/1.8
head combo.
On the 2 switch system, the switch that controls the light only (not
light/buzzer combo) is open until engine is running. i.e. engine off,
ign. on, the lifted ground actuates the electronics on the dynamic
unit making the light flash. That switch logic is reverse to the
single switch system. On that system, switch is closed until engine is
running. (see P97.56 current track 29)
My guess is that if you want to run just one wire (NO dynamic oil
pressure unit) you need a properly rated switch (bar) that is closed
when engine off, ign. on. On my ABA, I *think* this 'light only"
switch would be installed on the head as per the DV engine. With the
right switch installed, put your VOM between it and ground. Engine
off, continuity. Engine running, no continuity. Then check continuity
between wire in engine bay and cluster to ensure correct wire goes to
idiot light, then connect it all up.
I don't know if a switch from a single switch WBX or diesel would
suffice but as long as it's pressure rating is correct and is normally
closed until engine running, it should work.
FWIW, I installed the WBX dynamic oil pressure unit. I scratched my
head re: the logic but it's not too hard to do.
Neil.
--
Neil Nicholson '81 VanaJetta 2.0 "Jaco"
http://tubaneil.googlepages.com/
http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines
