Installing auto meter gauges

[Jmiller022]

I did a 5.3/4l60e swap, and am now trying to get my auto meter gauges wired up. I have the phantom series gauges. All electronic.

Speedometer
Tachometer
Oil pressure
Water temp
And fuel (wired and actually works) lol

I don't really have any experience with doing this and just kinda figured out the fuel gauge, call it dumb luck.

Are there any write ups on this?

Any help will be GREATLY appreciated!

Thank you
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[yossarian19]

For oil pressure & water temp, you want adapter fittings to go from the engine's metric to the senders NPT, like so http://www.speedwaymotors.com/Auto-M...ter,20928.html
Tachometer & speedo... I don't know. It's going to have something to do with your VSS, though, either raw signal or output from computer

[68GMCCustom]

What year is the 5.3?

My motor is a genIV...in which case many are pulling the gauge info off the can buss.

Since my motor is a genIV and I run a scan gauge I wound up wiring in my gauges as if it were say a sbc, wiring water temp and oil pressure senders using the above mentioned adapters. For the speedo I went with a GPS sender (used AutoMeters), mainly because I will run different tire sizes from time to time and wanted the speedo to stay accurate. For the tach I used the genIV Painless tach adapter...just taps into the crank sensor.


http://www.jegs.com/i/Painless-Perfo...ductId=1556815

[BR3W CITY]

Tach will install just like its instructions tell you to, but may require the use of a resistor on the signal line to get a readable signal. I have this in my build, or you can read http://67-72chevytrucks.com/vboard/s...d.php?t=445975 about how TR65 figured it out.

I have a few extra of these little resistor things (they come in a 5/10 pack), which I can send you if you need it.

Speedo will be pretty straightforward off the VSS, but be aware in some cases you need to wire straight off the VSS and NOT off the PCM output of the signal. IIRC the autometer speedo's look for a square wave pulse to give it input, and the ECM puts out a converted sine wave signal. This may not apply to all the speedo's, but it has come up before.

[68GMCCustom]

Originally Posted by BR3W CITY

Tach will install just like its instructions tell you to, but may require the use of a resistor on the signal line to get a readable signal.

I have a few extra of these little resistor things (they come in a 5/10 pack), which I can send you if you need it.

Hated to buy this Painless setup but didn't have a tach lead in my harness and was told there isn't one to have because the gauges run off the can buss. I have heard there is and I've heard there isn't a readable tach signal to tap on genIV motors coming from the ecm.....so is there is or is there ain't?

[BR3W CITY]

Originally Posted by 68GMCCustom

Hated to buy this Painless setup but didn't have a tach lead in my harness and was told there isn't one to have because the gauges run off the can buss. I have heard there is and I've heard there isn't a readable tach signal to tap on genIV motors coming from the ecm.....so is there is or is there ain't?

I was addressing the op on that post, but in regards to your question;

From what I undertand, you CAN get a tach signal off the GenIV motors. I saw some threads on doing it with the e38 pcm. You can use Pin48 which is the tach output...but the connection is "blank" on the plug, there is a pin but no wiring on the connection. You can open up the hole on the connector and add a wire. It looks like you need to change some settings in the pcm to make it output there. Take a look at this thread, it has a setup the guys used in HPT.

GEN IV E38 Tach Settings for aftermarket tach (autometer)

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Correct HPTuners tach settings for E38 ecm with 58x crank sensor.
Tach Output = Crank
Resolution - High =14
Resolution - Low =15
This will make the ECM output the correct frequency for a 2 pulse per revolution tach. The Duty cycle of the frequency will be 48.3%. 14/29

Tach output is on Pin 48 of the black connector.
You need to add a resistor (about 1k ohm) between the tach output and 12V to Pull-Up the Output signal to a usable voltage for aftermarket tachs.
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Here is how I came up with these numbers, for the people who care…
I have done testing to verify everything. This is what I have found to be true. I may have made errors but I do not think that I did.
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The tachometer I am using an Autometer Phantom II Part #7588.
You can configure the tach for
8 cyl mode (4 pulses per revolution)
6 cyl mode (3 pulses per revolution)
4 cyl mode (2 pulses per revolution)
4 cyl mode (1 pulses per revolution)

A 4 stroke 8 cylinder engine only fires 4 cylinders per engine revolution, 4 are on compression/firing stroke and 4 are on exhaust stroke. This is why tachs typically look for a 4 pulses per revolution.
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HP Tuners Settings

The tach output is OFF in the factory calibration.
The two options for tach output are frequency and crank. I do not know what frequency is, I tried it, it did not work for me, I got “crank” to work and I understand “crank” so I do not care about frequency.
The other variables are
Resolution - High = (number of periods the output stays high) I will call this HIRES
Resolution - Low = (number of periods the output stay low) I will call this LORES
These values need to be whole numbers.... The ECM can not handle decimal places.

Through some investigation I have found out that when "crank" is selected the ecm is going to output a pulse (or frequency, a pulse is a frequency) based on the 58x crank sensor. The minimum vales in HIRES/LORES are 1/1. This means for every 2 crank pulses you will get 1 tach output pulse from the ECM. The highest resoulution tach output signal is 29 pulses per revolution. 58/2

To verify this I entered 1/1 in the HIRES/LORES fields and hooked up my trusty Fluke to the tach signal at idle
670 rpm = 11.17 revolutions per second
11 revs per second * 29 pulses per rev = 324 pulses per second = 324 HZ
I verified 324 HZ with my fluke at 670 rpm.

I have heard that the numbers in the HIRES and LORES needed to be equal and I have also heard that they needed to be dividable by 60. I do not think either of those statements are true.
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An Autometer tach works off of frequency. Frequency can be measured as the time between the leading edges of 2 pulses. The tach does not really care what the duty cycle is as long as it is within an acceptable range.

I set my tach in 4 cylinder mode.
I set 15/15 in HIRES/LORES
At 3000 rpm I read 97 hz with a 50% duty cycle.

I set my tach in 4 cylinder mode.
I set 10/20 in HIRES/LORES
At 3000 rpm I read 97 hz with a 33% duty cycle.

The tach still read correctly even though the duty cycle was very different. The frequency remained the same.

Ok so now I have verified duty cycle can be changed and that crank is based on the 58 tooth crank sensor.
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The highest number of pulses my tach allows for 8 cylinder mode is 4 pulses per revolution. The higher the pulses per rev the faster the tach will respond. Higher = better.

58/4 pulses per rev =14.5 total crank pulses for each ECM tach output pulse.
14.5 = 7.25 and 7.25 in HIRES/LORES
These are not acceptable numbers. Must be a whole number CRAP……

If you use 7/7 your tach will be reading 3.4% too high.
It will read 2900 when your actual engine speed is 2800.

If you use 7/8 your tach will be reading 3.4% too low.
It will read 2900 when your actual engine speed is 3000.


I switched my tach to 4 cylinder mode. The tach is now looking for 2 pulses per engine revolution. 58/2 pulses per rev = 29 total crank pulses for each ECM tach output pulse.
29 = 14 and 15 in HIRES/LORES

If you use 15/15 your tach will be reading 3.4% too low.
It will read 2900 when your actual engine speed is 3000.

If you use 14/15 your tach will be reading 100% accurate.

I should add. Being 3% off on an analog tach is not a big deal. I tried to run my engine at 3000 rpm and compare my tach to the actual scanner readout. I saw a negligible difference even when the tach was off. Hopefully I helped someone understand what the signal is and how to TUNE it…. ( this can be useful is trying to create a signal to work with a non GM gauge cluster...) Settings of 15/15 will probably not be noticable especially on an analog tach.

Now the older GEN III engines used a 24x system....
If you set the HIRES and LORES to 3/3 you would get exactly 4 pulses per engine revolution, the world is happy.
3+3 = 6 total crank pulses to provide 1 ECM output pulse.
24/6 = 4 pulses per revolution

Thats is what I have learned. I wanted to truly understand this info as it was not clearly stated (for me) anywhere on the internet on what the number actually mean.

7/7 can be used for a 4 pulse tach but your tach will read 3.4% high. It could possibly respond faster then having your tach set in 4 cylinder mode.

http://ls1tech.com/forums/generation...ch-signal.html

[502ms]

Originally Posted by 68GMCCustom

Hated to buy this Painless setup but didn't have a tach lead in my harness and was told there isn't one to have because the gauges run off the can buss. I have heard there is and I've heard there isn't a readable tach signal to tap on genIV motors coming from the ecm.....so is there is or is there ain't?

That makes no sense. My tach is running off of my harness coming off my PCM. I will, however have to tap into the VSS to get my new autometer speedo to work.
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[ls1nova71]

Originally Posted by 502ms

That makes no sense. My tach is running off of my harness coming off my PCM. I will, however have to tap into the VSS to get my new autometer speedo to work.
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Gen III's are different than Gen IV's. The newer stuff doesn't run a traditional wire to the gauges, but rather runs all the info to the stock cluster via the CAN BUS. You'll be alright tapping directly into your VSS wires since you have a manual transmission. The original poster was having an issue of the VSS signal being messed up by doing that and it was causing erratic shifting of the PCM controlled 4l60e, which is why he needed to use the speed signal wire coming out of the PCM.
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[68GMCCustom]

Originally Posted by 502ms

That makes no sense. My tach is running off of my harness coming off my PCM. I will, however have to tap into the VSS to get my new autometer speedo to work.
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no...its more about cents when it's the newer stuff.
genIV isn't the same as genIII. got its own little digital network...making pulling an analog signal a bit different.

[Jmiller022]

See I had issues with tieing directly to the VSS it "dirty'd" up the signal to the PCM so i had erratic shifts. So I wired straight from the PCM and calibrated it and its +/-1mph from my gps.

[Jmiller022]

On my 2001 PCM

The pins for the speedo and tach are:

Speedometer - C2 (red connector) pin #50 Dark green/white wire
Tach - C2 pin #10 white wire
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Also have to set the tach (mine is autometer) to the 4cyl mode(2 pulse). Has to do with the pulses and get ways over my head.

[68GMCCustom]

I tried this or something similar with my HPT and couldn't get a signal or any tach response. I didn't have the proper pin setup tho. When I saw this Painless device that connects to crank sensor and was in the middle of an order from Summit I thought what the heck...

[mooseknuckles]

I had to switch my autometer elec.tach from 8cyl (4pulse) to 6cyl (3pulse) to get it to work accurately....the diagram with the resistor is from jon at PSI...

[mooseknuckles]

still can't get the speedo calibrated.....it's out about 30kph.

[Jmiller022]

Finally got my speedo done and calibrated I just had a duh moment and didn't strip the wire back before crimping it...lol it was a 2am thing...lol

Originally Posted by mooseknuckles

still can't get the speedo calibrated.....it's out about 30kph.

Are you doing the full 2miles(3.2km)?

How fast are you going while doing it? I did mine in a an empty Walmart parking lot just doing laps around the perimeter watching the GPS closely at about 20-25mph steady. And I stopped dead on 2 miles. Mine is about 1-2mph off at 60mph, and I think that's pretty good.

If that still doesn't correct yours I'd send it back if possible and have autometer look at it.

[mooseknuckles]

Originally Posted by Jmiller022

Finally got my speedo done and calibrated I just had a duh moment and didn't strip the wire back before crimping it...lol it was a 2am thing...lol



Are you doing the full 2miles(3.2km)?

How fast are you going while doing it? I did mine in a an empty Walmart parking lot just doing laps around the perimeter watching the GPS closely at about 20-25mph steady. And I stopped dead on 2 miles. Mine is about 1-2mph off at 60mph, and I think that's pretty good.

If that still doesn't correct yours I'd send it back if possible and have autometer look at it.

my speedo is in km, and it says to run the pre-marked 2km distance, done that 100 times, try to run steady at 45-50kph...got correct gears and tire size in my tune....

[Billett]

Originally Posted by mooseknuckles

still can't get the speedo calibrated.....it's out about 30kph.

I just bought the same set for my 68 lq4 setup. They look great. I only received the speedo, but the water temp and oil pressure are on their way. I'll get the tach down the road. How bad were they to connect?
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[Jmiller022]

Any update?
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[mooseknuckles]

no haven't been back out yet...

[mooseknuckles]

so....ran it up till the pulse count was at 5000, stopped, hit the button, and now it's dead on...thank you all for the help!

[Jmiller022]

Originally Posted by mooseknuckles

so....ran it up till the pulse count was at 5000, stopped, hit the button, and now it's dead on...thank you all for the help!

Awesome, glad I was able to help!
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