[Supras] Odd electrical system issues.

[Dan Gyoba]

On 8 Aug 2007 at 12:01, tom wrote:

> Dan, 
> You have to replace the NA tach with the Turbo tach.  Dr Jones,  had a
> write up on altering the NA tach
> [http://www.4cefed.com/conversion.html] but just switching the tach
> was most simple for me.  
> 
> Tom 87NA-T

Sorry.  Forgot to mention that.  I have swapped out the tach, I'm aware of the difference.

Thanks for the replies so far, but I guess I'll go a bit more in detail of what's up.

I've been reading up on what needs to be done for this swap for over 10 years now.  I figure I'm 
about as prepared as I could have been going in, but there are some things to note:

-- The donor car is an '87 Turbo, 5 speed.  It had TEMS and ABS.

-- My car is an early production model '89 NA 5 speed.  No TEMS, but it does have ABS.

As can be expected, there are some things here and there that don't connect between the two 
harnesses.

I see in the TSRM that there's a line from the headlight relay to the TCCS "LP" pin.  It stands 
to reason that this is where the problem is.  What the chassis harness thinks is connected to the 
"LP" pin isn't.  If I were to locate and sever this connection (WTF does the ECU need to be able 
to turn on the headlights for anyway?  Or maybe it wants to know when the headlights are on?) 
hopefully this won't throw a code.

Maybe the LP and IG- pins are in different locations on the ECU.  This would explain both 
problems.  (Convenient if it worked that way.  Convenient in an annoying way.  Blargh.)

Dan Gyoba
'89 NA 450,322 kms, Turbo swap in progress
http://www.abstractconsulting.com/~dan