accel dfi thruster

[69MyWay]

A couple of questions for the Thruster experts.

1. I am wiring the cooling fan accessory pack harness. Got it hooked up and just noticed the relays are NORMALLY CLOSED - ie, the fans want to run all the time unless they get a ground input.

So - does the PCM send a ground singal all the time, then break that ground to trigger the fans???? If not, I need to re-wire the relays. This is confusing because I've never seen a normally closed relay for electric fans - they are always normally open and then get the ground to close the relay either through a temp switch, or from the computer.

2. The a/c harness interrupt. Noting question #1 - the Vintage Air a/c sytem has a trinary switch that makes a ground signal to trigger a cooling fan relay once the clutch is activated. The Gen VII is suppose to be able to "interupt this" so that we can program at how much throttle the a/c will disengage. Now...because of #1 above - I'm confused as heck as to what to do with that ground signal and how that ties back in. I can't even simply feed this into the fan relays now because if I ground them...they shut the fan off. This is really two questions at once, as the Gen VII interupts the power feed to the clutch - not the ground coming from the trinary switch - but it is also suppose to allow for control of the fans through the main fan hook up based on a input signal from the a/c through the accessory harness.

3. THE BIG ONE - For some reason, after you turn the key on the first time - the computer doesn't want to drop power to the ignition AFTER you turn it back off. My local installer/tuner tells me he has now seen this several times and talks about making a jumper harness with a light in it...etc. to override the problem but he isn't sure how to fix it. In other words, you can't shut the car off with the key once it starts. Something is getting energized and staying engergized. I have the distributor and PCM feed coming off the car's coil feed that is hot when the key is on, and stays hot while starting so the fuel pump and computer/ignition will stay hot while cranking. However, when you turn the key off, the stock 76 trans am wiring shuts power off to this lead...but the system is now keeping the power energized. There are three switched power leads. One to the distributor, one to the 300 box, and one to the PCM. They should all require to keep power on during the crank cycle - and I'm not aware of any other way to fee that off the ignition switch than what I'm doing now. The other main power lead is direct to the battery as indicated along with a direct lead to battery ground.

What gives? I'm sure this is simple to correct.

[69MyWay]

One other thing...AGain, I may be blind and just not seeing the download - but the transmission lock up harness came with no instructions as well.

I haven't a clue where to hook these wires and what to verify inside the pan before I fill it up with fluid.

[camcojb]

Originally Posted by 69MyWay

A couple of questions for the Thruster experts.

1. I am wiring the cooling fan accessory pack harness. Got it hooked up and just noticed the relays are NORMALLY CLOSED - ie, the fans want to run all the time unless they get a ground input.

So - does the PCM send a ground singal all the time, then break that ground to trigger the fans???? If not, I need to re-wire the relays. This is confusing because I've never seen a normally closed relay for electric fans - they are always normally open and then get the ground to close the relay either through a temp switch, or from the computer.

2. The a/c harness interrupt. Noting question #1 - the Vintage Air a/c sytem has a trinary switch that makes a ground signal to trigger a cooling fan relay once the clutch is activated. The Gen VII is suppose to be able to "interupt this" so that we can program at how much throttle the a/c will disengage. Now...because of #1 above - I'm confused as heck as to what to do with that ground signal and how that ties back in. I can't even simply feed this into the fan relays now because if I ground them...they shut the fan off. This is really two questions at once, as the Gen VII interupts the power feed to the clutch - not the ground coming from the trinary switch - but it is also suppose to allow for control of the fans through the main fan hook up based on a input signal from the a/c through the accessory harness.

3. THE BIG ONE - For some reason, after you turn the key on the first time - the computer doesn't want to drop power to the ignition AFTER you turn it back off. My local installer/tuner tells me he has now seen this several times and talks about making a jumper harness with a light in it...etc. to override the problem but he isn't sure how to fix it. In other words, you can't shut the car off with the key once it starts. Something is getting energized and staying engergized. I have the distributor and PCM feed coming off the car's coil feed that is hot when the key is on, and stays hot while starting so the fuel pump and computer/ignition will stay hot while cranking. However, when you turn the key off, the stock 76 trans am wiring shuts power off to this lead...but the system is now keeping the power energized. There are three switched power leads. One to the distributor, one to the 300 box, and one to the PCM. They should all require to keep power on during the crank cycle - and I'm not aware of any other way to fee that off the ignition switch than what I'm doing now. The other main power lead is direct to the battery as indicated along with a direct lead to battery ground.

What gives? I'm sure this is simple to correct.

1. Sure sounds like the relays are wired wrong. I've used many different efi systems and all of them that control the fans do it through the ground for the relay. The fans do not run until the computer grounds the relay, with a menu in the software to control the on and off temps for the fans. A quick test would be to set the on and off temps in the software, say 180 degrees on and 170 degrees off and turn the key on. If the fans are running and the water temp in the software isn't at 180 degrees then they are not wired correctly, or are defective in some way.

2. The ground trigger from the trinary switch should be wired into the relay ground. It automatically turns the fans on if the a/c is on regardless of engine temp, to control the a/c pressures. I don't think this is an issue with your wot a/c compressor shut off feature as the computer will still be controlling the fans through temps, so even if the a/c ground signal is removed the computer ground will keep the fans running.

3. If you have the correct key on wiring then it sounds like the ignition is feeding back and keeping the circuit going. May need a diode placed in line to prevent the feedback when the key is shut off. I would think that the instructions for the ignition box would mention this as a possibility if it's a common issue. Have you tested the lines individually to see which one is providing the feedback (un-plug two of them and just hook up one at a time until it occurs).

Jody

[69MyWay]

1. Re-wired the fan relays - all is well there now.

2. A/C harness taken care of when fan relays were in proper working order (switched to normally open and ground activated)

3. Still can't shut it off. Didn't look into this in much detail tonight. Don't know if I have an improper hook up, or if I need a diode or light wire hooked to the system through the main power feed????

4. Transmission - pulled the pan and studied the harness and wires there. Figured out to hook up the ground, then run the other lead back from the 4th gear pressure switch so the computer would sense 4th gear - then ran the hot feed coming from the relay to the TCC solenoid.

Got it running for a brief moment -

Need to figure out the no-shut-off thing...then set up for the cam break in.

https://www.youtube.com/watch?v=ZXvVjBZCpwk

[camcojb]

good job Chris.

Jody

[69MyWay]

Okay - looks like I connected the 12+ switched (OUTPUT) from the dual synch back to 12+ switched. While that seems to make sense on the surface, it is an output 12, not input. This appears to be what is keeping it energized and in a circle loop after turning the key on and not allowing the car to shut off.

I'll snip that and see where we are.

Friday I'll have time to tinker. All systems should be go. The local programmer will come over for the break in start up and initial program.

From there we'll see what this system has to offer.

I am thinking about writing a quick reference "Accel Thruster for Dummies"....(people like me that work 40 hour a week jobs behind a desk and only play with this stuff once in a while...). LOL!

[69MyWay]

It lives.....

Turned out the ecm was bad and was not firing the #1 injector. That was causing all kinds of early start up (and cam break in) issues. Put in another computer after testing all wiring - etc, and confirmed the problem.

Put about 70 miles on it this weekend. So far so good. Just had a cooling fan issue where it quit turning on the secondary fan. Don't know if that is the relay, wires...etc, but with the cool weather not a problem right now.

I am pleased to say the car is smooth and our gamble on doing the 700R4 and 2:41 rear gears worked. It is just at an idle around 60 mph - hard to tell the engine is running, then just a tip of the toe and it roars.

The best part is the shaker hood went back on with no mods due to the lower profile of the 1,000 cfm throttle body.

[slammed con]

i recently purchased one i wish i could return it the harness is a joke and by the time you purchase everything to use this system but thats just my opinion

[Efi69Cam]

Originally Posted by slammed con

i recently purchased one i wish i could return it the harness is a joke and by the time you purchase everything to use this system but thats just my opinion

define a joke harness?

[slammed con]

A joke harness is an accel harness thats three feet too long and having three of the brand new sensor connectors falling off ans having to take ut to a locak accel dealer and they said theyve seen it before but they fixed it for free then my sequential distributor sub harness came and it was fitted with the wrong weather packs once again it eas fixed for free so hopefully that will give you an idea accel cheeraleader