A couple of wiring Questions?? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

skoffice · 01-08-2011, 12:25 AM

I am putting a 6.0 in my 64 C10 and I converted the harness from DBW to DBC. I am just about ready to finish it all up, but I have a couple questions..

1. I have a 4L65E and want to hook up the purple brake switch wire. Does anyone have a diagram for this? Can I just tap it right into my stock brake switch?

2. There is a Purple wire labeled "Crank Volt" in my pinout, it is pin 59 on the Red/Green connector. Does anyone know what this is for? It is a thin gauge wire like the rest, so I don't think it's the starter wire.

3. Lastly, I know that the pre 65 ignition switch does not supply constant 12V to the "ignition hot" during cranking. Does anyone have a suggestion on which ignition I should get that would fit in my stock dash location? Can I just buy one for a 66?

Thanks for looking and any help you guys have to offer!!!

matthew20061 · 01-08-2011, 06:19 AM

Well I can answer question #1 when I did my swap harness I just tapped into the brake switch wire under the dash by the pedal and so far so good for two years its been working perfect. Looks like a nice swap!

skoffice · 01-08-2011, 11:48 AM

Great thank you! My buddy just got his harness from Howell yesterday and it looked like his had a pink 12V wire that was supposed to hook up along with the purple one so it threw me off. Thanks! How are you liking your swap? What kind of mileage are you getting? I'm just too excited to get this thing going, I'm on the downhill run now!

matthew20061 · 01-08-2011, 05:42 PM

Quote:

Originally Posted by skoffice

Great thank you! My buddy just got his harness from Howell yesterday and it looked like his had a pink 12V wire that was supposed to hook up along with the purple one so it threw me off. Thanks! How are you liking your swap? What kind of mileage are you getting? I'm just too excited to get this thing going, I'm on the downhill run now!

I love it so far! I had originally swapped in a 5.3L with a cam and some other upgrades, which was an awesome motor and got great mileage I think around 20? I know for a fact it got 17 on the highway out to the racetrack then I did two passes and came back so I thought that was pretty good mileage for running two 1/4 mile passes and then driving on the highway!

The 6.0L swap was yet to be tested because its too icy and snowy here.

skoffice · 01-08-2011, 07:42 PM

Wow thats awesome! I'll be a happy camper if I can get between 18-20 on the freeway. That 6.0 you're building should be pretty nasty! What did you run at the track with the 5.3? The weather here where I am isn't snowy or icy but I'm ready for some warm weather already!

matthew20061 · 01-08-2011, 08:02 PM

The cam I used in the 5.3L was a Comp Cam LSR Series 215/223 .607/.610 lift on 112 LSA it was designed for 5.3's and is suppose to make lots of torque and it definitely did! I think our 6.0's should be pretty good on gas as well. I know when I switched from a 2000 GMC with a 5.3 to my Silverado SS the SS ended up getting better mileage driving around town and the same on the highway. Don't know how that worked lol.

skoffice · 01-08-2011, 09:13 PM

I've heard that too actually. My thought on that was the engine has more power so it's doing less work to move the truck around? I could be completely wrong though haha. Jeez that's a healthy sized cam for a 5.3. Mine is .540/.540 and 232@ .050 from Clay Smith, I've never seen a cam like this in an LS engine before so I'm curious how it's going to act with that much duration.

Big Port Jimmy 6 · 01-08-2011, 11:12 PM

You could wire in a relay to fire up the ignition to the pcm while the Switch is in start.
87 to Batt
85 to ground
86 to the start signal from the NS switch
30 to the pcm ign feed
This would allow you to keep the stock switch. Jay

skoffice · 01-08-2011, 11:26 PM

That's a pretty good idea there Jimmy. That's what I'm wondering with the whole 12V thing, would the relay click off when I go to put it in crank? Or would it stay on? I heard that the voltage drops to 5 or 6V during cranking, maybe that's enough to keep the relay engaged?

Big Port Jimmy 6 · 01-09-2011, 04:03 PM

It should be fine it doesn't take much to tip in a relay. Jay

skoffice · 01-10-2011, 01:22 AM

Ya I might as well try that. If it doesn't work it won't hurt to have the relay in there anyway.

I found that the purple wire is pin 59 on the green or red connector for a 2002 pickup. No luck on figuring out what its for yet

**Clyde65** · 01-10-2011, 11:27 AM

If you have the stock fuse box, I would seriously consider changing that to an upgraded harness/fuse box. It wont survive the power forced through the wires.

My PCm gets the ign hot all time from the fuse box, one of the accessory blades.

skoffice · 01-11-2011, 02:26 AM

I changed all my fuses boxes over to the blade style and have a seperate keyed ign. circuit for the coils, injectors, etc. Thanks to some deep reading in all the sticky info posted by Thealien I figured out that I can eliminate the Purple 59 pin. I'm so close to having this harness done I'm just tying up the loose ends now..
Thanks guys!

01-08-2011, 06:19 AM	#2
matthew20061 69' Chevy Stepside Join Date: Mar 2008 Location: Anchorage, Ak Posts: 526	Re: A couple of wiring Questions?? Well I can answer question #1 when I did my swap harness I just tapped into the brake switch wire under the dash by the pedal and so far so good for two years its been working perfect. Looks like a nice swap! __________________ -Matthew -69' Chevy Custom/10 Shortbed Stepside 2WD "Copperhead" - Restored, 6.0L LQ9 Built. L92 Heads and LS3 Intake with Comp Cam 223/231 .610/.617 112 LSA, 4L60E with Shift Kit and Circle-D 3200 Stall Converter ~Build Thread -1957 Chevy BelAir 2 Door Post Sedan, Full Frame off Restoration done myself - 6.0L with T56 six speed -1957 Chevy BelAir 2 Door Post Sedan - Nearly rust free AK car, Project in the waiting -2003' Chevy Silverado SS AWD 6.0L! - Daily Driver

01-08-2011, 11:48 AM	#3
skoffice Registered User Join Date: Apr 2007 Location: Elk Grove, CA Posts: 375	Re: A couple of wiring Questions?? Great thank you! My buddy just got his harness from Howell yesterday and it looked like his had a pink 12V wire that was supposed to hook up along with the purple one so it threw me off. Thanks! How are you liking your swap? What kind of mileage are you getting? I'm just too excited to get this thing going, I'm on the downhill run now! __________________ 1964 C10 Shortened Shortbed Cammed LQ9 P&P 1967 C10 Trophy Truck BB 438 (soon to be worked on again)

01-08-2011, 07:42 PM	#5
skoffice Registered User Join Date: Apr 2007 Location: Elk Grove, CA Posts: 375	Re: A couple of wiring Questions?? Wow thats awesome! I'll be a happy camper if I can get between 18-20 on the freeway. That 6.0 you're building should be pretty nasty! What did you run at the track with the 5.3? The weather here where I am isn't snowy or icy but I'm ready for some warm weather already! __________________ 1964 C10 Shortened Shortbed Cammed LQ9 P&P 1967 C10 Trophy Truck BB 438 (soon to be worked on again)

01-08-2011, 08:02 PM	#6
matthew20061 69' Chevy Stepside Join Date: Mar 2008 Location: Anchorage, Ak Posts: 526	Re: A couple of wiring Questions?? The cam I used in the 5.3L was a Comp Cam LSR Series 215/223 .607/.610 lift on 112 LSA it was designed for 5.3's and is suppose to make lots of torque and it definitely did! I think our 6.0's should be pretty good on gas as well. I know when I switched from a 2000 GMC with a 5.3 to my Silverado SS the SS ended up getting better mileage driving around town and the same on the highway. Don't know how that worked lol. __________________ -Matthew -69' Chevy Custom/10 Shortbed Stepside 2WD "Copperhead" - Restored, 6.0L LQ9 Built. L92 Heads and LS3 Intake with Comp Cam 223/231 .610/.617 112 LSA, 4L60E with Shift Kit and Circle-D 3200 Stall Converter ~Build Thread -1957 Chevy BelAir 2 Door Post Sedan, Full Frame off Restoration done myself - 6.0L with T56 six speed -1957 Chevy BelAir 2 Door Post Sedan - Nearly rust free AK car, Project in the waiting -2003' Chevy Silverado SS AWD 6.0L! - Daily Driver Last edited by matthew20061; 01-08-2011 at 08:02 PM.

01-08-2011, 09:13 PM	#7
skoffice Registered User Join Date: Apr 2007 Location: Elk Grove, CA Posts: 375	Re: A couple of wiring Questions?? I've heard that too actually. My thought on that was the engine has more power so it's doing less work to move the truck around? I could be completely wrong though haha. Jeez that's a healthy sized cam for a 5.3. Mine is .540/.540 and 232@ .050 from Clay Smith, I've never seen a cam like this in an LS engine before so I'm curious how it's going to act with that much duration. __________________ 1964 C10 Shortened Shortbed Cammed LQ9 P&P 1967 C10 Trophy Truck BB 438 (soon to be worked on again)

01-08-2011, 12:25 AM	#1
skoffice Registered User Join Date: Apr 2007 Location: Elk Grove, CA Posts: 375	A couple of wiring Questions?? I am putting a 6.0 in my 64 C10 and I converted the harness from DBW to DBC. I am just about ready to finish it all up, but I have a couple questions.. 1. I have a 4L65E and want to hook up the purple brake switch wire. Does anyone have a diagram for this? Can I just tap it right into my stock brake switch? 2. There is a Purple wire labeled "Crank Volt" in my pinout, it is pin 59 on the Red/Green connector. Does anyone know what this is for? It is a thin gauge wire like the rest, so I don't think it's the starter wire. 3. Lastly, I know that the pre 65 ignition switch does not supply constant 12V to the "ignition hot" during cranking. Does anyone have a suggestion on which ignition I should get that would fit in my stock dash location? Can I just buy one for a 66? Thanks for looking and any help you guys have to offer!!! __________________ 1964 C10 Shortened Shortbed Cammed LQ9 P&P 1967 C10 Trophy Truck BB 438 (soon to be worked on again) Last edited by skoffice; 01-10-2011 at 01:18 AM.

01-08-2011, 11:12 PM	#8
Big Port Jimmy 6 Addicted to Rust Join Date: Dec 2009 Location: Abbeville SC Posts: 1,030	Re: A couple of wiring Questions?? You could wire in a relay to fire up the ignition to the pcm while the Switch is in start. 87 to Batt 85 to ground 86 to the start signal from the NS switch 30 to the pcm ign feed This would allow you to keep the stock switch. Jay __________________ Current trucks: (48 GMC100 320 inliner) Gone (48 Suburban in pieces) Sold 87 GMC CCSB 5.3 4l60E Daily Driver ECTA National record holder XO/PP We never really grow up, we just learn how to act in public.

01-08-2011, 11:26 PM	#9
skoffice Registered User Join Date: Apr 2007 Location: Elk Grove, CA Posts: 375	Re: A couple of wiring Questions?? That's a pretty good idea there Jimmy. That's what I'm wondering with the whole 12V thing, would the relay click off when I go to put it in crank? Or would it stay on? I heard that the voltage drops to 5 or 6V during cranking, maybe that's enough to keep the relay engaged? __________________ 1964 C10 Shortened Shortbed Cammed LQ9 P&P 1967 C10 Trophy Truck BB 438 (soon to be worked on again)

01-09-2011, 04:03 PM	#10
Big Port Jimmy 6 Addicted to Rust Join Date: Dec 2009 Location: Abbeville SC Posts: 1,030	Re: A couple of wiring Questions?? It should be fine it doesn't take much to tip in a relay. Jay __________________ Current trucks: (48 GMC100 320 inliner) Gone (48 Suburban in pieces) Sold 87 GMC CCSB 5.3 4l60E Daily Driver ECTA National record holder XO/PP We never really grow up, we just learn how to act in public.

01-10-2011, 01:22 AM	#11
skoffice Registered User Join Date: Apr 2007 Location: Elk Grove, CA Posts: 375	Re: A couple of wiring Questions?? Ya I might as well try that. If it doesn't work it won't hurt to have the relay in there anyway. I found that the purple wire is pin 59 on the green or red connector for a 2002 pickup. No luck on figuring out what its for yet __________________ 1964 C10 Shortened Shortbed Cammed LQ9 P&P 1967 C10 Trophy Truck BB 438 (soon to be worked on again)

01-10-2011, 11:27 AM	#12
Clyde65 1965 Chevy C10, 2005 4.8L/4l60 Join Date: Aug 2004 Location: DFW Texas Posts: 8,546	Re: A couple of wiring Questions?? If you have the stock fuse box, I would seriously consider changing that to an upgraded harness/fuse box. It wont survive the power forced through the wires. My PCm gets the ign hot all time from the fuse box, one of the accessory blades. __________________ Clyde65 Rebuild of Clyde http://67-72chevytrucks.com/vboard/s...84#post8338184 69 Aristocrat Lo Liner build http://67-72chevytrucks.com/vboard/s...84#post7561684 *support our troops!*

01-11-2011, 02:26 AM	#13
skoffice Registered User Join Date: Apr 2007 Location: Elk Grove, CA Posts: 375	Re: A couple of wiring Questions?? I changed all my fuses boxes over to the blade style and have a seperate keyed ign. circuit for the coils, injectors, etc. Thanks to some deep reading in all the sticky info posted by Thealien I figured out that I can eliminate the Purple 59 pin. I'm so close to having this harness done I'm just tying up the loose ends now.. Thanks guys! __________________ 1964 C10 Shortened Shortbed Cammed LQ9 P&P 1967 C10 Trophy Truck BB 438 (soon to be worked on again) Last edited by skoffice; 01-11-2011 at 04:31 AM.



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