Pro Stock John

iTrader: (34)

I am going to go full standalone with the FAST, but I am unsure if my coolant temp and oil pressure gauges will work in the dash afterwards, I have been told that they both do not go through the engine control harness, anyone know which ones do and which ones don't?

whitt1

Oil pressure doesn't go through the harness,but I beleive water temp does.

Pro Stock John

iTrader: (34)

Thanks for the reply, that totally helps.

Anyone know about water temp?

Scalpel

iTrader: (4)

The oil pressure is controlled by a serial input to the dash, that's about as much input as I can provide.

Pro Stock John

iTrader: (34)

You are just confirming what Whitt said Levi? I appreciate all the help I can get, I need to buy gauges so as not to get stuck next week after the conversion.

I know we can control the fans thru FAST, but I'm not sure about water temp.

slow

iTrader: (7)

water temp on 98 only is a dedicated wire to the third wire in the ECT sensor, unique to 1998 cars only.

I believe this has no interface with the computer, and should work fine. I don't have schematics to look at though

Ryan.

Pro Stock John

iTrader: (34)

That would mean that it's not thru the engine control harness right? That would be sweet, I'd just be losing speedo and tach, and I have a 5" tach for now.

kp

iTrader: (34)

Looking at the wiring diagram you would loose the speedo, tach and fuel guage not using the PCM. Temp sender uses the dark green wire and the oil pressure sender uses a tan wire.

Brains

iTrader: (7)

Hey John, why not piggyback the FAST and keep the factory gauges working? Sure, its easier to pull all the factory junk out, but its pimp to leave it in

Scalpel

iTrader: (4)

John, you should call Speartech for some info. They know these harnesses inside and out.

Pro Stock John

iTrader: (34)

Brian, I am already running the partial FAST (fuel controlled, but timing controlled by LS1 Edit) as a piggyback, but I am running out of room under the cowl plus if I have to troubleshoot stuff anytime in in the future there are so many wires to check that it would take forever. I already have a non-working speedo since I did not do the stuff I needed to do for the T400 swap, and for some reason my fuel gauge does not work (CAS tank) so it's not like I'm going to be missing much now as it is. And I have a centrally mounted 5" Autometer tach in the car now.

kp

iTrader: (34)

If I had a DFI or fast the stock PCM would be long gone if all I needed it for was gauges

I would just use mecanical oil and water gauges anyhow. A car like yours should have a pro light for the oil pressure also IMO.