ATTN elec. Gurus, lighting/dimming question - Page 3

SLKWrx · 04-24-2003, 04:01 PM

Quick question. Pin 7 of the 741.. is it tied to the output as well as ground or straight to ground. I'm assuming ground but its always good to be sure. Pin 7.. thats Vcc right? I'm thinking it is.. but I'm not sure.

-- Steve

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vrg3 · 04-24-2003, 06:02 PM

Pin 7 is Vcc, yes. Do not hook it up to ground! It should be connected directly to the Illum(+) input. This way the circuit will be powered when the headlights are on, and will not be powered when the headlights are off.

In the schematic, where wires cross, they are only actually connected if they have a dot at the joint.

jjunior887 · 04-29-2003, 08:29 PM

Just to let everyone know the setup that vrg3 designed works perfect for my three Omori gauges, they dim(with the factory dimmer) and match very well with my dash lighting now. Anyone electrically inclined(not me) should try this out, it does work well.

BTW i don't think there is much to worry abouyt with three gauges, I took a reading toward the beginning of this thread and I was only seeing about .5 amp with all three gauges hooked up. If someone who knows what they are doing and has three omori's could verify this i would really appreciate it. -James

ride5000 · 04-30-2003, 08:27 AM

i nominate this thread for a sticky, or a FAQ submission, since it seems like a fairly common problem and an elegant solution!

ken

Scoob · 05-29-2003, 09:37 PM

Don, when you nail this little black box down, can I get one please?

Cheers,

Scoob.

jjunior887 · 05-29-2003, 09:47 PM

Hey vrg3, where did you get the blue plug in the pic? It looks like it would work for our cars too.

vrg3 · 05-30-2003, 01:12 AM

I just looked in my tub o' Subaru stuff.

I think it came off a random engine wiring harness I had. There are a lot of 2-pin connectors on our cars (and other cars, especially Japanese ones) that are identical to these.

If it wasn't off an engine wiring harness, it must have been a stock speaker connector for some car.

svelt · 06-06-2003, 06:18 PM

I made the Omori meter light dim with the stock lamps by using a transister to invert the variable voltage; so when stock lights are dimmed meter lamp dims ~ applies a varying positive voltage controled by the varying neg voltage.

Scoob · 06-06-2003, 06:56 PM

Can you post a circuit digram for us non elec. engineers? Thanks!

Scoob.

turboICE · 11-23-2003, 12:12 PM

Bump for those looking to dim Omori lights.

SilverJA · 11-27-2003, 02:08 AM

Would anybody be willing to make and sell one of these transistor/converter things, like the one vrg3 made?

I just want to get my gauges and dash to work in sync.

Any help of further insight is appreciated.

Thanks
Joel

breed · 01-14-2004, 07:42 PM

(*really* glad I found this thread as it helped me immensely on my Omori install in my WRX)

Thanks vrg3! and the rest of you (jehcpa, jjunior887, Thaison) for your input. I just made the do-hicky with the 741 and TIP31 transistor--works great! I'm using it to dim my Omori EGT and boost gauges mounted in an Autometer instrument bezel

pics here

One question... I left my EGT sensor unplugged since I don't have the manifold tapped yet. Is it safe to do that? The EGT registers its max when I do this......

vrg3 · 01-16-2004, 04:34 AM

Joel - I know I'm a month or two late... but I just PM'd you.

breed - Awesome. Glad it's working for you.

It should be okay to leave the EGT sensor unplugged, but why not just cut power to the gauge itself to be safe?

skivvie · 01-16-2004, 01:07 PM

Someone really needs to submit a circuit diagram for this to Scoobymods.com! My gauges are coming in next week, so if no one steps up before i get them installed i'll do a write up.

Scoob · 01-16-2004, 08:52 PM

Check page 2, there's a link with a circuit diagram in there.. I missed it too, only found it yesterday! Duh!

Scoob.

Moondongle · 02-16-2004, 05:28 PM

I tried to get my circuit to work with my electrical Omori gauges but couldn't. Can those that are running the electrical Omori's tell me how you hooked up the Omori harness? There are five leads on the Omori harness. White, Red, Brown, Black (2pcs). To get the gauges to read properly, I made the following connections. White to the switched light power in the Subaru harness. Red to an ignition power source in the fuse box. Black leads were grounded, and brown wasn't used. The gauges read and work fine. The gauge lights turn on and off with the car lights, but do not dim.
Any help would be greatly appreciated.

Thanks.

turboICE · 02-16-2004, 08:27 PM

You have connected properly.

They will not dim because Subaru dims dash lights through the ground & Omori does not provid a backlight ground as both black wires are connected internally - kind of the topic of this entire thread...

You would need the circuit being discussed which will convert the ground based dimming into a v+ source dimmer to dim your gauges.

vrg3 · 02-16-2004, 08:29 PM

Uh, Moondongle did build the circuit to reverse the illumination voltage, so he doesn't need a separate backlight ground. He just needs a clearer explanation of which wire is which than is provided in the Omori "documentation."

turboICE · 02-16-2004, 08:39 PM

That was not entirely clear in his post given the connections he made, I apologize.

The red is the power for the gauge and if an electrical gauge also for the sender.

White is the power for the backlight.

The black provides ground to both the gauge power (sender) and also the backlight.

The brown is for an external warning light for the 60mm gauges but is included on all harnesses even ones that don't have the output.

The white would need to receive its signal through the circuit if it is being used - the current connection does not sound like the circuit is being used.

vrg3 · 02-16-2004, 08:47 PM

So connecting red to +12v, white to the output of the circuit, and black to ground should work?

Charged Performance · 02-16-2004, 10:05 PM

OEM lighting + goes to illum +
OEM lighting ground goes to illum -
Omori white wire would go to out
Ground of course goes to ground

Omori red will go to an ignition on hot wire
Omori black goes to ground

If the circuit works as advertised and is connected properly then you should get the expected results.

skivvie · 02-16-2004, 10:57 PM

I've got pics and am working on a write up for this right now, expect it this week.

Moondongle · 02-16-2004, 10:59 PM

turboICE: Sorry I wasn't clear in my post regarding my connections. After much frustration, I just gave up the dimming circuit and connected the gauges to work, hence my connections direct from Omori harness to Suby harness.

Thanks for clarifying the Omori harness. I couldn't make heads or tails of the brown lead. Now it makes sense. Let me just reiterate with Charged Perfomance posted here to make absolutely sure.

OEM + (Switched lights) connects to VRG3 circuit Illum +
OEM - (Dimming Lights) connects to VRG3 circuit Illum -
Omori White connects to VRG3 output lead
Omori Black is grounded
Omori Red connected to ignition switched power
Omori Brown connects to external warning lamp if desired

Thanks for the help.

Charged Performance · 02-16-2004, 11:34 PM

turboICE is my personal account - sometimes when checking PMs I end up posting along without realizing the user id I am under.

Yes your reiteration is accurate - adding that the VRG3 itself has a constant ground connection that needs to be made as well at the bottom of the schematic.

We have not tested this circuit but others said it had worked.

You did connect the gauges properly for use without the circuit in your original post - the only wire you change when using the circuit is the one that the white wire connects to.

Ed.

Moondongle · 02-17-2004, 12:07 AM

OK. I'm now clear and thanks for your help. I'll try these connections when I have the new circuit. I may have fried a chip either soldering or trying different connections, so I'll try it with a fresh one.

04-29-2003, 08:29 PM	#53
jjunior887 Scooby Specialist Member#: 16738 Join Date: Mar 2002 Chapter/Region: MAIC Location: Charles Town, WV Vehicle: 2015 WRX Limited CWP	Just to let everyone know the setup that vrg3 designed works perfect for my three Omori gauges, they dim(with the factory dimmer) and match very well with my dash lighting now. Anyone electrically inclined(not me) should try this out, it does work well. BTW i don't think there is much to worry abouyt with three gauges, I took a reading toward the beginning of this thread and I was only seeing about .5 amp with all three gauges hooked up. If someone who knows what they are doing and has three omori's could verify this i would really appreciate it. -James Last edited by jjunior887; 04-29-2003 at 08:37 PM.

05-29-2003, 09:37 PM	#55
Scoob Scooby Specialist Member#: 6204 Join Date: Apr 2001 Location: In the "313" Vehicle: 2002 WRX Sedan WR Blue	Little black box Don, when you nail this little black box down, can I get one please? Cheers, Scoob.

01-14-2004, 07:42 PM	#62
breed Scooby Newbie Member#: 8929 Join Date: Aug 2001 Location: LA, CA Vehicle: 2002 WRX Sedan Silver	thanks! (really glad I found this thread as it helped me immensely on my Omori install in my WRX) Thanks vrg3! and the rest of you (jehcpa, jjunior887, Thaison) for your input. I just made the do-hicky with the 741 and TIP31 transistor--works great! I'm using it to dim my Omori EGT and boost gauges mounted in an Autometer instrument bezel pics here One question... I left my EGT sensor unplugged since I don't have the manifold tapped yet. Is it safe to do that? The EGT registers its max when I do this......

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04-24-2003, 04:01 PM	#51
SLKWrx Scooby Specialist Member#: 8247 Join Date: Jul 2001 Chapter/Region: Tri-State Location: Woolwich, NJ Vehicle: 2016 Outback 2005 Lotus Elise	Quick question. Pin 7 of the 741.. is it tied to the output as well as ground or straight to ground. I'm assuming ground but its always good to be sure. Pin 7.. thats Vcc right? I'm thinking it is.. but I'm not sure. -- Steve * Registered users of the site do not see these ads.

04-24-2003, 06:02 PM	#52
vrg3 Scooby Specialist Member#: 25796 Join Date: Oct 2002 Location: Cleveland, OH Vehicle: 2012 Impreza	Pin 7 is Vcc, yes. Do not hook it up to ground! It should be connected directly to the Illum(+) input. This way the circuit will be powered when the headlights are on, and will not be powered when the headlights are off. In the schematic, where wires cross, they are only actually connected if they have a dot at the joint.

04-30-2003, 08:27 AM	#54
ride5000 Scooby Guru Member#: 32792 Join Date: Feb 2003 Chapter/Region: NESIC Location: lincoln, ri Vehicle: 2003 GGA MBP 12.9 / 105+	i nominate this thread for a sticky, or a FAQ submission, since it seems like a fairly common problem and an elegant solution! ken

05-29-2003, 09:47 PM	#56
jjunior887 Scooby Specialist Member#: 16738 Join Date: Mar 2002 Chapter/Region: MAIC Location: Charles Town, WV Vehicle: 2015 WRX Limited CWP	Hey vrg3, where did you get the blue plug in the pic? It looks like it would work for our cars too.

05-30-2003, 01:12 AM	#57
vrg3 Scooby Specialist Member#: 25796 Join Date: Oct 2002 Location: Cleveland, OH Vehicle: 2012 Impreza	I just looked in my tub o' Subaru stuff. I think it came off a random engine wiring harness I had. There are a lot of 2-pin connectors on our cars (and other cars, especially Japanese ones) that are identical to these. If it wasn't off an engine wiring harness, it must have been a stock speaker connector for some car.

06-06-2003, 06:18 PM	#58
svelt Scooby Newbie Member#: 35693 Join Date: Apr 2003 Location: wi Vehicle: 03 wrx wagon white	I made the Omori meter light dim with the stock lamps by using a transister to invert the variable voltage; so when stock lights are dimmed meter lamp dims ~ applies a varying positive voltage controled by the varying neg voltage.

06-06-2003, 06:56 PM	#59
Scoob Scooby Specialist Member#: 6204 Join Date: Apr 2001 Location: In the "313" Vehicle: 2002 WRX Sedan WR Blue	Can you post a circuit digram for us non elec. engineers? Thanks! Scoob.

11-23-2003, 12:12 PM	#60
turboICE Scooby Specialist Member#: 33979 Join Date: Mar 2003 Chapter/Region: South East Location: Charlotte, NC Vehicle: 2006 STi WRB	Bump for those looking to dim Omori lights.

11-27-2003, 02:08 AM	#61
SilverJA Scooby Newbie Member#: 11544 Join Date: Oct 2001 Chapter/Region: RMIC Location: West Haven, UT Vehicle: 93, 05, 16 Taco TRD 01 RS 02 WRX 06 XT 08 STi	Would anybody be willing to make and sell one of these transistor/converter things, like the one vrg3 made? I just want to get my gauges and dash to work in sync. Any help of further insight is appreciated. Thanks Joel

01-16-2004, 04:34 AM	#63
vrg3 Scooby Specialist Member#: 25796 Join Date: Oct 2002 Location: Cleveland, OH Vehicle: 2012 Impreza	Joel - I know I'm a month or two late... but I just PM'd you. breed - Awesome. Glad it's working for you. It should be okay to leave the EGT sensor unplugged, but why not just cut power to the gauge itself to be safe?

01-16-2004, 01:07 PM	#64
skivvie Scooby Newbie Member#: 29719 Join Date: Nov 2002 Location: Draper, UT Vehicle: '06 WRX Wagon Silver	Someone really needs to submit a circuit diagram for this to Scoobymods.com! My gauges are coming in next week, so if no one steps up before i get them installed i'll do a write up.

01-16-2004, 08:52 PM	#65
Scoob Scooby Specialist Member#: 6204 Join Date: Apr 2001 Location: In the "313" Vehicle: 2002 WRX Sedan WR Blue	Check page 2, there's a link with a circuit diagram in there.. I missed it too, only found it yesterday! Duh! Scoob.

02-16-2004, 05:28 PM	#66
Moondongle Scooby Newbie Member#: 39552 Join Date: Jul 2003 Chapter/Region: BAIC Location: Santa Cruz, CA Vehicle: 2003 WRX Wagon WRB	I tried to get my circuit to work with my electrical Omori gauges but couldn't. Can those that are running the electrical Omori's tell me how you hooked up the Omori harness? There are five leads on the Omori harness. White, Red, Brown, Black (2pcs). To get the gauges to read properly, I made the following connections. White to the switched light power in the Subaru harness. Red to an ignition power source in the fuse box. Black leads were grounded, and brown wasn't used. The gauges read and work fine. The gauge lights turn on and off with the car lights, but do not dim. Any help would be greatly appreciated. Thanks.

02-16-2004, 08:27 PM	#67
turboICE Scooby Specialist Member#: 33979 Join Date: Mar 2003 Chapter/Region: South East Location: Charlotte, NC Vehicle: 2006 STi WRB	You have connected properly. They will not dim because Subaru dims dash lights through the ground & Omori does not provid a backlight ground as both black wires are connected internally - kind of the topic of this entire thread... You would need the circuit being discussed which will convert the ground based dimming into a v+ source dimmer to dim your gauges.

02-16-2004, 08:29 PM	#68
vrg3 Scooby Specialist Member#: 25796 Join Date: Oct 2002 Location: Cleveland, OH Vehicle: 2012 Impreza	Uh, Moondongle did build the circuit to reverse the illumination voltage, so he doesn't need a separate backlight ground. He just needs a clearer explanation of which wire is which than is provided in the Omori "documentation."

02-16-2004, 08:39 PM	#69
turboICE Scooby Specialist Member#: 33979 Join Date: Mar 2003 Chapter/Region: South East Location: Charlotte, NC Vehicle: 2006 STi WRB	That was not entirely clear in his post given the connections he made, I apologize. The red is the power for the gauge and if an electrical gauge also for the sender. White is the power for the backlight. The black provides ground to both the gauge power (sender) and also the backlight. The brown is for an external warning light for the 60mm gauges but is included on all harnesses even ones that don't have the output. The white would need to receive its signal through the circuit if it is being used - the current connection does not sound like the circuit is being used.

02-16-2004, 08:47 PM	#70
vrg3 Scooby Specialist Member#: 25796 Join Date: Oct 2002 Location: Cleveland, OH Vehicle: 2012 Impreza	So connecting red to +12v, white to the output of the circuit, and black to ground should work?

02-16-2004, 10:05 PM	#71
Charged Performance Vendor Member#: 40645 Join Date: Jul 2003 Location: Jersey City, NJ	OEM lighting + goes to illum + OEM lighting ground goes to illum - Omori white wire would go to out Ground of course goes to ground Omori red will go to an ignition on hot wire Omori black goes to ground If the circuit works as advertised and is connected properly then you should get the expected results.

02-16-2004, 10:57 PM	#72
skivvie Scooby Newbie Member#: 29719 Join Date: Nov 2002 Location: Draper, UT Vehicle: '06 WRX Wagon Silver	I've got pics and am working on a write up for this right now, expect it this week.

02-16-2004, 10:59 PM	#73
Moondongle Scooby Newbie Member#: 39552 Join Date: Jul 2003 Chapter/Region: BAIC Location: Santa Cruz, CA Vehicle: 2003 WRX Wagon WRB	turboICE: Sorry I wasn't clear in my post regarding my connections. After much frustration, I just gave up the dimming circuit and connected the gauges to work, hence my connections direct from Omori harness to Suby harness. Thanks for clarifying the Omori harness. I couldn't make heads or tails of the brown lead. Now it makes sense. Let me just reiterate with Charged Perfomance posted here to make absolutely sure. OEM + (Switched lights) connects to VRG3 circuit Illum + OEM - (Dimming Lights) connects to VRG3 circuit Illum - Omori White connects to VRG3 output lead Omori Black is grounded Omori Red connected to ignition switched power Omori Brown connects to external warning lamp if desired Thanks for the help.

02-16-2004, 11:34 PM	#74
Charged Performance Vendor Member#: 40645 Join Date: Jul 2003 Location: Jersey City, NJ	turboICE is my personal account - sometimes when checking PMs I end up posting along without realizing the user id I am under. Yes your reiteration is accurate - adding that the VRG3 itself has a constant ground connection that needs to be made as well at the bottom of the schematic. We have not tested this circuit but others said it had worked. You did connect the gauges properly for use without the circuit in your original post - the only wire you change when using the circuit is the one that the white wire connects to. Ed.

02-17-2004, 12:07 AM	#75
Moondongle Scooby Newbie Member#: 39552 Join Date: Jul 2003 Chapter/Region: BAIC Location: Santa Cruz, CA Vehicle: 2003 WRX Wagon WRB	OK. I'm now clear and thanks for your help. I'll try these connections when I have the new circuit. I may have fried a chip either soldering or trying different connections, so I'll try it with a fresh one.