Cascade Crew

QwkTrip · Posted: Wed Oct 01, 2014 10:30 pm Post subject:

Kind of got in my old mode tonight where I look at stuff and think but don't do anything. Eventually snapped out of it and got to work. I have 6 wires from engine harness that will go through C100 so I made a 6-pin connector that will plug into the engine harness. That really helped clean up the large mass of wiring in that corner.

I also decided to run the fuel pump Hot Wire kit through the interior because I didn't like what I was seeing under the car. I found a large grommet on the firewall next to the clutch master and put the wire through there. Haven't decided where I'm punching through at the back. I'm also threading the transmission VSS wires and reverse interlock through that same grommet. I could have connected that stuff to unused wires at C100 but honestly, I just don't want to go through the work to find those wires on the interior and re-route. Sounds like a huge pain in the rear to me. Turns out that I won't have a single wire going through the connector at passenger kick panel.

I also remembered today that I have a wide band O2 gauge stored somewhere. I might as well install that on the passenger side header instead of plugging the hole.

aaron_sK · Posted: Thu Oct 02, 2014 6:23 am Post subject:

That firewall grommet was for the speedo cable in your car's previous life as a Camaro. Laughing

Are you using the Racetronix kit? That was the one I had and I was very disappointed in it's design and how they ran wires every which way needlessly. I ended up cutting it up and using the connectors and wiring in my own configuration.

If you pull up the rear carpet you will see where GM dropped through with the fuel pump wiring. There is a square hole for the connector and it is not really conducive to a grommet, so consider going through the metal next to it, or removing it and replacing it with a patch with a pass-through for the wires.

Twilightoptics · Posted: Thu Oct 02, 2014 6:27 am Post subject:

Use the gm connector!

aaron_sK · Posted: Thu Oct 02, 2014 6:31 am Post subject:

That is an option. By the time you get back that far in the car the voltage drop by making the wiring "chokepoint" slightly longer is not such a big deal.

It will be annnoying to solder though. The GM connector is a 16ga wire, his hotwire kit is 10ga. Laughing

Twilightoptics · Posted: Thu Oct 02, 2014 10:31 am Post subject:

Blah blah blah :0)

QwkTrip · Posted: Thu Oct 02, 2014 10:55 am Post subject:

I was wondering what that grommet was for! Ya, I've got the Racetronix kit. And I agree, it is kind of goofy because it is plug and play for a 4th gen harness. But I do have a 4th gen tank so not so crazy in my case.

I have other uses for the stock connector. The original fuel pump feed is now the trigger for Racetronix pump relay. The original fuel pump ground is now the fuel gauge ground since the 4th gen tank is plastic and needs a ground added. Pretty slick idea if you ask me! Very Happy

I worked this out a couple years ago so just replace LS1 PCM with Holley HP.

QwkTrip · Posted: Thu Oct 02, 2014 3:48 pm Post subject:

These are the new connections I am making to C100. Connections for backup lights and gauges for oil, coolant, and tachometer. And using the old fuel pump power as the new fuel pump relay driver. I trimmed all wires to same length and made a pigtail with a 6-pin Metripack connector to make it all plug and play.

QwkTrip · Posted: Thu Oct 02, 2014 4:16 pm Post subject:

Dang it.... I forgot about the alternator lamp driver. I guess I'll tap that into the 10 ga. pink wire from F4. There should be plenty of capacity left in that circuit.

Edit: I just realized F4 is not fused. I think I'll add an inline fuse to it in the engine bay so that the vehicle doesn't shut down if trans wires or alternator shorts out.

aaron_sK · Posted: Thu Oct 02, 2014 6:18 pm Post subject:

Time to put your own fusebox in. Run how ever many circuits you want.

This box had a dedicated fuse just for the alternator light. Laughing

QwkTrip · Posted: Thu Oct 02, 2014 7:34 pm Post subject:

I do have an underhood fuse box and I just started working on it tonight. Smile

I changed my mind about that pink F4. It's probably going to run the switched B+ in my fuse box. The box has fan relays, pump relay, and AC relay, and an open relay slot. I don't need the pump relay so I could use that for something else (20A circuit).

QwkTrip · Posted: Fri Oct 03, 2014 11:26 pm Post subject:

I'm looking at how to do AC controls and I would like confirmation from somebody that knows what they are doing. I have a Holley HP system so no LS1 controller. The AC has to be stand-alone. All my blower motor wiring is in tact, but the only thing I have of my AC wiring is what came out of the firewall, so I can build whatever controls I want.

'89 Firebird. I notice there are 3 ways these 'Birds were wired. Each uses the head unit in the dash to power the compressor clutch. The difference is how the power gets to the compressor clutch. All go through the low pressure switch (pressure cycling switch) and from that point,

VIN F: Goes to high pressure switch --> to compressor clutch --> ground.
VIN S: Goes to high pressure switch --> A/C relay (controlled by engine ECM) --> compressor clutch --> ground
VIN 2: Goes to A/C relay (controlled by engine ECM) --> compressor clutch --> ground
Each version uses engine ECM to bump idle up when compressor clutch is powered.

My car is a VIN S. I don't see any reason to keep the A/C relay, do you? I can just copy VIN F and route the A/C compressor request in series through the low pressure switch, then through the high pressure switch, then to compressor clutch. At that point it will simply be a system that works on the low and high pressure switches.

Meanwhile, #1 radiator fan needs to be on at all times when A/C is on, so tap that relay control off the LT GRN wire from head unit when the A/C is on. And #2 radiator fan should be on when the high pressure switch is closed, so tap that relay control from the low side of the high pressure switch. Does all this sound right? These will be parallel fan controls to the coolant temp based strategy I will use in the Holley HP system.

P.S. How in the world does VIN 2 get by without a high pressure switch???

chevymad · Posted: Sat Oct 04, 2014 12:09 pm Post subject:

High pressure switch is simply a safety in case the fan doesn't work or something gets plugged. Otherwise it never really does anything.

Only problem I see with having a completely stand alone system is what to do at WOT. The ECM disconnects the ac when at WOT to prevent over revving of the ac compressor. Also has the benefit of not using any power for ac when you're wot.

Also make sure your electric fan comes on when ac is selected.

QwkTrip · Posted: Sat Oct 04, 2014 12:56 pm Post subject:

Oops! I didn't think about WOT. Thanks for the input. I had some schematics made up with ideas but need to go back to drawing board again about this WOT issue.

QwkTrip · Posted: Sat Oct 04, 2014 2:46 pm Post subject:

I'm kind of stuck at the moment and tired of looking at my computer screen. Posted a help request at the Holley HP EFI forum.

Simple, but no WOT shutdown and only activates one fan.

All the bells and whistles, but I have no idea how to program it and it kind of sucks that it uses up so many of the custom inputs and outputs.

aaron_sK · Posted: Sat Oct 04, 2014 3:48 pm Post subject:

GM only ever switched one fan via A/C in a dual-fan setup AFAIK.

You could easily trigger both fans full on by grounding both your fan relays through the compressor switch.

That would require only one output from the ECM (WOT) to open the relay. Easy money. Cool

QwkTrip · Posted: Sat Oct 04, 2014 5:12 pm Post subject:

You can't ground both fans together on the same circuit because it will allow the field coils to cross-talk. If one fan is grounded then both will go on every time.

Also, I think there is a problem with Option 1. AC clutch will not shut off because it is being fed by Fan 2 field coil so long as the high pressure switch is closed, which is pretty much whenever the AC compressor is running. Circular logic and can't turn off the compressor until pressure goes too high.

aaron_sK · Posted: Sat Oct 04, 2014 5:59 pm Post subject:

Hmm yeah. Must have had my head up my ass earlier. Laughing

Looking at it again it seems like GM ran a third pressure switch on the TBI cars without ECM control to trigger the fan, at least in '92. It also looks like they split the feed off the back of the A/C switch (light and dark green wires):

http://www.austinthirdgen.org/mkportal/modules/contents/images/diagram_1992_coolant_fan_V8_vinE.jpg

http://www.austinthirdgen.org/mkportal/modules/contents/images/diagram_1992_air_conditioning_compressor_controls_C60_manual_V8_vinE.jpg

I still feel there is some simple and obvious solution that I am overlooking, but I can't put my finger on it.

QwkTrip · Posted: Sat Oct 04, 2014 6:17 pm Post subject:

QwkTrip · Posted: Sat Oct 04, 2014 6:47 pm Post subject:

QwkTrip · Posted: Sat Oct 04, 2014 7:56 pm Post subject:

Okay, I have a better working understanding of the AC system now. Option 1 simply isn't going to work. I've deleted it.

I need both low and high pressure switch for safety so need them both in series with the compressor clutch. Any relay or control of the compressor clutch should be downstream of those pressure switches.