Where to run tach lighting wire - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Mrturner1 · 03-01-2016, 11:00 PM

Can I run the backlighting wire on an autometer tach somewhere in the fuse panel? If so, where? It's a 70 c10 thanks guys

'68 Newtricks · 03-01-2016, 11:09 PM

If you have an auto column, you can tap into the light for the gear indicator. If not, you can tap into the plug for the gauges. If you don't like that, you can test which AUX port on the fuse block is key hot and constant.

**VetteVet** · 03-02-2016, 01:12 AM

The gear selector light wire is not a light wire it is a fiber optic line from the dash cluster light to the gear indicator. Do not use that.

You can tap into the gauge plug with the two gray wires from the fuse panel.
One of them comes from from the fuse panel to bring power to the gauge lights and the other one runs over to the heater panel. it will continue over to the glove box if you have a light in that. If you want the tach light to dim you will have to use the gray wire. If you connect it to the fuse panel key on hot, terminal the tach light will be on anytime the key is on.

You could splice it into the brown wire on the headlight switch and it will come on with the lights but it will not dim.

Andy4639 · 03-02-2016, 01:34 AM

I always tap into the grey wire on the cluster. That way it deems when you turn the head light switch. You can plug into the cluster feed beside it is a connection to feed lights.

Mrturner1 · 03-02-2016, 01:48 AM

Quote:

Originally Posted by Andy4639

I always tap into the grey wire on the cluster. That way it deems when you turn the head light switch. You can plug into the cluster feed beside it is a connection to feed lights.

I plugged it into that cluster feed, and it lit the tach and gauge cluster for a second when I pulled out the headlight switch (turned on) and then the tach and gauge cluster went out and do not light up anymore

Andy4639 · 03-02-2016, 02:28 AM

Check the fuse.

**VetteVet** · 03-02-2016, 02:37 AM

The PNl Lts fuse is where you should have tapped into, as it fuses the gray wire to the instrument lights. Check it and the cluster feed fuse which feeds the gauges in the cluster.

The instrument lights are powered off of the headlight switch by a green wire which runs to the fuse panel PNL LTS fuse. It runs through the headlight dimmer rheostat and then to the fuse panel.

'68 Newtricks · 03-02-2016, 04:12 AM

Quote:

Originally Posted by VetteVet

The gear selector light wire is not a light wire it is a fiber optic line from the dash cluster light to the gear indicator. Do not use that.

Really? How weird. I just figured it was like my reproduction column. Separate wire for that bulb, splice in and done

I didn't have my factory non-tilt column long enough to see. Interesting

**Classic Bowties** · 03-02-2016, 05:31 AM

Quote:

Originally Posted by '68 Newtricks

Really? How weird. I just figured it was like my reproduction column. Separate wire for that bulb, splice in and done

I didn't have my factory non-tilt column long enough to see. Interesting

The OE automatic trans tilt columns did have the power wire and bulb socket setup for lighting the shift indicator lens, the non tilt automatic columns had the fiber optic lead coming off the dash cluster for lighting the shift indicator pointer. Mel

Mrturner1 · 03-02-2016, 12:02 PM

Quote:

Originally Posted by Andy4639

Check the fuse.

Quote:

Originally Posted by VetteVet

The PNl Lts fuse is where you should have tapped into, as it fuses the gray wire to the instrument lights. Check it and the cluster feed fuse which feeds the gauges in the cluster.

The instrument lights are powered off of the headlight switch by a green wire which runs to the fuse panel PNL LTS fuse. It runs through the headlight dimmer rheostat and then to the fuse panel.

I'm back at it today, thank you guys for the help

zosoppp · 11-01-2016, 11:05 PM

Silly question here, does any know whether the tap between the panel lts and the cluster feed fuse is protected/fed from the cluster feed fuse or the panel lts fuse?

Other way of asking is that tap feed dim-able (panel) or always hot in run/start (cluster)?

[/QUOTE]

zosoppp · 11-03-2016, 12:33 AM

Quote:

Originally Posted by zosoppp

Silly question here, does any know whether the tap between the panel lts and the cluster feed fuse is protected/fed from the cluster feed fuse or the panel lts fuse?

Other way of asking is that tap feed dim-able (panel) or always hot in run/start (cluster)?

[/QUOTE]

So got out the ole VOM and determined that the open tap between panel lts and cluster feed is tied to the panel lights fuse (and therefore is dimmable).

03-01-2016, 11:00 PM	#1
Mrturner1 Registered User Join Date: Nov 2015 Location: Colfax California Posts: 1,644	Where to run tach lighting wire Can I run the backlighting wire on an autometer tach somewhere in the fuse panel? If so, where? It's a 70 c10 thanks guys

03-01-2016, 11:09 PM	#2
'68 Newtricks Registered User Join Date: Feb 2014 Location: Los Angeles area :( Posts: 499	Re: Where to run tach lighting wire If you have an auto column, you can tap into the light for the gear indicator. If not, you can tap into the plug for the gauges. If you don't like that, you can test which AUX port on the fuse block is key hot and constant. __________________ '68 C10 SWB '85 K30 Blazer

03-02-2016, 01:12 AM	#3
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,718	Re: Where to run tach lighting wire The gear selector light wire is not a light wire it is a fiber optic line from the dash cluster light to the gear indicator. Do not use that. You can tap into the gauge plug with the two gray wires from the fuse panel. One of them comes from from the fuse panel to bring power to the gauge lights and the other one runs over to the heater panel. it will continue over to the glove box if you have a light in that. If you want the tach light to dim you will have to use the gray wire. If you connect it to the fuse panel key on hot, terminal the tach light will be on anytime the key is on. You could splice it into the brown wire on the headlight switch and it will come on with the lights but it will not dim. __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

03-02-2016, 01:34 AM	#4
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,945	Re: Where to run tach lighting wire I always tap into the grey wire on the cluster. That way it deems when you turn the head light switch. You can plug into the cluster feed beside it is a connection to feed lights. __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

03-02-2016, 02:28 AM	#6
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,945	Re: Where to run tach lighting wire Check the fuse. __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

03-02-2016, 02:37 AM	#7
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,718	Re: Where to run tach lighting wire The PNl Lts fuse is where you should have tapped into, as it fuses the gray wire to the instrument lights. Check it and the cluster feed fuse which feeds the gauges in the cluster. The instrument lights are powered off of the headlight switch by a green wire which runs to the fuse panel PNL LTS fuse. It runs through the headlight dimmer rheostat and then to the fuse panel. __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

11-01-2016, 11:05 PM	#11
zosoppp Registered User Join Date: Mar 2014 Location: Lincoln Park, NJ Posts: 190	Re: Where to run tach lighting wire Silly question here, does any know whether the tap between the panel lts and the cluster feed fuse is protected/fed from the cluster feed fuse or the panel lts fuse? Other way of asking is that tap feed dim-able (panel) or always hot in run/start (cluster)? [/QUOTE] __________________ 1970 C10 LWB 350SBC, SM330 Muncie (not saginaw SM326) (on tree), 3.07 open (assumed), PS, PB, Idiot lights

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