Yes you can. But it’s better to run a sense wire. I spliced into the sense wire into driver side coil 12v+
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It's what commands the regulator inside the alternator. The alternator's regulator is designed to have a target voltage - usually 14 on an LS style alternator - but NOT always. If it sees voltage at the sense wire below the target voltage, then it regulates the voltage production of the alternator to the target. Pretty simple concept that has been employed in internally regulated alternators since they were introduced (mostly). How it does it exactly, I can't explain the physics of it.
Something really neat though, you can use the Holley to put an output to the sense wire that PWM (pulse width modulated) to increase voltage as needed. Most every stock alternator will make 16 volts without issue for short periods. This is way to make you injectors and fuel pump larger than they actually are. Also, its way to make your voltage consistent during a run down the drag strip because voltage drop is humongous tuning dilemma. Now 1/2 to 1 volt or so isn't a deal breaker, but much more than a volt and now your tune can become unstable. For daily use, burnouts and an occasional trip down the track, it's nothing to get worried about. But if you're making tons of go and have to battle voltage drop, then it sucks.
Ford and GM have been doing this with a stock PCM for quite some time now. It's an easy way to increase mileage, performance, battery life and alternator life. But for most it's just not needed.
Something really neat though, you can use the Holley to put an output to the sense wire that PWM (pulse width modulated) to increase voltage as needed. Most every stock alternator will make 16 volts without issue for short periods. This is way to make you injectors and fuel pump larger than they actually are. Also, its way to make your voltage consistent during a run down the drag strip because voltage drop is humongous tuning dilemma. Now 1/2 to 1 volt or so isn't a deal breaker, but much more than a volt and now your tune can become unstable. For daily use, burnouts and an occasional trip down the track, it's nothing to get worried about. But if you're making tons of go and have to battle voltage drop, then it sucks.
Ford and GM have been doing this with a stock PCM for quite some time now. It's an easy way to increase mileage, performance, battery life and alternator life. But for most it's just not needed.
Thanks for the detailed explanation, it’s really appreciated! Looks like I’ll go with the 4 pin connector and run it to the Holley.
How’s NY? I grew up in Staten Island, and we had a place up north in Orange County. Man it’s been years since I’ve been back that way, seems like a lifetime ago.
We are Cuomo free presently, not sure if that a hood thing or not - time will tell.
I have extended family that lives ‘down state’ in Orange Co lol. What is considered good money there is double of what it’s considered here.
Here we consider downstate anything south of Hancock or Kingston. If you don’t get lake effect snow, then you’re downstate.
Anyway, things are good here as far as I’m concerned. But if you ask my wife she’ll tell you how much it sucks here.
How far are you from firing this thing up?
I have extended family that lives ‘down state’ in Orange Co lol. What is considered good money there is double of what it’s considered here.
Here we consider downstate anything south of Hancock or Kingston. If you don’t get lake effect snow, then you’re downstate.
Anyway, things are good here as far as I’m concerned. But if you ask my wife she’ll tell you how much it sucks here.
How far are you from firing this thing up?
Yea, you’re way up north. Tell your wife it could always be worse, we live across the bridge from Portland and I honestly believe it’s going to be the first city in the US that gets fenced off….
The amount of transients is staggering, and the garbage is everywhere, it’s horrible what’s happening to that city. Whatever you see on the news…it’s worse.
Mechanically the car is done, need to finish wiring the Holley, and fans and such. Things got me scared though, I’m horrible with electronics to begin with. Downloaded the software last night and started looking it over. Of course they don’t have a base calibration for DBW, 4l80e, 24x, and turbo so I’ll have to figure that out. I also got their dual solenoid boost controller with the dome pressure sensor. Looking through the instructions, seems you need a PhD to know half of what they’re talking about.
I put a 4.8, turbo, 4l60e in it last year with the stock ECU, stepped up to the Holley because it took months to get a dyno appointment, and it was $750. a shot.
The amount of transients is staggering, and the garbage is everywhere, it’s horrible what’s happening to that city. Whatever you see on the news…it’s worse.
Mechanically the car is done, need to finish wiring the Holley, and fans and such. Things got me scared though, I’m horrible with electronics to begin with. Downloaded the software last night and started looking it over. Of course they don’t have a base calibration for DBW, 4l80e, 24x, and turbo so I’ll have to figure that out. I also got their dual solenoid boost controller with the dome pressure sensor. Looking through the instructions, seems you need a PhD to know half of what they’re talking about.
I put a 4.8, turbo, 4l60e in it last year with the stock ECU, stepped up to the Holley because it took months to get a dyno appointment, and it was $750. a shot.
If you use the wizard, then you'll be fine as long as you don't matt it the 1st time it sees the street...I've never messed with a DBW, but it can't be that complex. Holley has made this so that it's easy for anyone as long as you hookup what they say to hookup. Make sure your grounds are real grounds and wire the Holley 12v+ and 12v- directly to the battery (no exception).
So I have a 2005 Tahoe LS Swap with a 160 amp alternator. I did the wiring harness myself and left the ground cable sensor wired in figuring that might be a critical item,
The issue I have is that after 30 minutes of driving I get a voltage drop and the drive by wire drops out engine stumbles then the Volt meter goes to 13.9 Volts but no throtle.
The volt meter just prior might be at 12.3 to 12.6 then its like a split second drop and engine flutters and TBW inop - coast to a stop turn off engine - and on restart battery is right a 11.7 volts - engine starts, sometimes the TBW is back other times I have to wait for volts to go above 12,1 and then restart and everything is good for a while - volts at 13.9 charging but then after a while same scanrio and repeat - get about 30 min of worry free and bam volt drop below 12v.
As a side note this does not happen ALL the time there have been times I drive the car over 200 miles in a trip and never have an issue - but I do not drive the car regularly its a T-Top so its only in nice weather - e.g. no rain. I have noticed that is I run the High beams at night eventually they start to loose power so switch to low beam, but the volts seem to hold. this is a 1986 Lux Sprt Mnte Carlo with a 1987 LS harness - the original harness was melted down from an engine fire, so started with a rolling chassis and a complete engine body and light harness donated from a 1987 Monte Carlo.
The ECM was performance tuned as a stand alone so I have no idea how the charging controls are set up.
the car has a power inverter, electric locks, windows, 2 amps 6 speaker surround sound, 10 inch woofer, a GPS /WiFi enabled multi media panel and LED internal Lighting - the A/c and Blower Motor have not been wired in yet until I get the voltage drop figured out.
Other than that car drives great until volt drop, any insight is helpful - I am putting a direct battery feed volt and amp meter in the car as well the one in dash. The in dash is part of a dakota digital gauge setup using the alternator sense wire.
The issue I have is that after 30 minutes of driving I get a voltage drop and the drive by wire drops out engine stumbles then the Volt meter goes to 13.9 Volts but no throtle.
The volt meter just prior might be at 12.3 to 12.6 then its like a split second drop and engine flutters and TBW inop - coast to a stop turn off engine - and on restart battery is right a 11.7 volts - engine starts, sometimes the TBW is back other times I have to wait for volts to go above 12,1 and then restart and everything is good for a while - volts at 13.9 charging but then after a while same scanrio and repeat - get about 30 min of worry free and bam volt drop below 12v.
As a side note this does not happen ALL the time there have been times I drive the car over 200 miles in a trip and never have an issue - but I do not drive the car regularly its a T-Top so its only in nice weather - e.g. no rain. I have noticed that is I run the High beams at night eventually they start to loose power so switch to low beam, but the volts seem to hold. this is a 1986 Lux Sprt Mnte Carlo with a 1987 LS harness - the original harness was melted down from an engine fire, so started with a rolling chassis and a complete engine body and light harness donated from a 1987 Monte Carlo.
The ECM was performance tuned as a stand alone so I have no idea how the charging controls are set up.
the car has a power inverter, electric locks, windows, 2 amps 6 speaker surround sound, 10 inch woofer, a GPS /WiFi enabled multi media panel and LED internal Lighting - the A/c and Blower Motor have not been wired in yet until I get the voltage drop figured out.
Other than that car drives great until volt drop, any insight is helpful - I am putting a direct battery feed volt and amp meter in the car as well the one in dash. The in dash is part of a dakota digital gauge setup using the alternator sense wire.
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Help me out here, you have a G-body with an '05 LS swapped in that has a DBW throttle body? And you are losing voltage randomly?
Yes...
86 MC LS with 2005 VIN-T Tahoe 5.3 DBW - random volt drops - has a 12V AGP battery - not sure what others have used for charging system management in similar LS swaps. Nothing crazy on the LS swap all factory OEM - except the engine appears to be a performance rebuild - engine was really clean for 85k miles according to the salvage invoice slip - and on when having it tuned the performance center said it is conservatively 450 HP.
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