Ignition hot 12V source in the engine bay? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

UATahoe · 03-25-2013, 03:43 PM

Hey guys, just curious if you guys have some recommendations on a place to tie in to an ignition hot 12V source? Getting ready to wire up my electric fans and a new O2 sensor for my 87 R10

willett · 03-25-2013, 04:39 PM

If I were you I would get a big constant duty solenoid ran off the battery and run the control wire off of an ign controlled port in the fuse box
Posted via Mobile Device

UATahoe · 04-12-2013, 09:50 AM

I will look in to that. Was hoping i could find somewhere in the engine bay and not have to run all the way back in to the fuse box.

Jonboy · 04-12-2013, 10:17 AM

If you run it on the drivers side, it won't be that long. The O2 sensor is already pretty close to the fuse box.

UATahoe · 04-12-2013, 10:29 AM

Roger that. The coolant sensor for the fans will be on the passenger side head but still not a big deal. I cant say i have actually looked at the fuse box yet inside the engine bay. I will look when i get home. I was planning on tieing the two 2 together into the same point. I have a wiring diagram for the truck so hopefully i can figure out which fuses are ignition driven for the 87. I am guessing i can tie in to the fuse box from the engine bay side right? Havent really fooled too much with the electrical on these yet.

Jonboy · 04-12-2013, 11:15 AM

Just put the wire through the speedo cable grommet, and tie into the fuse box under the dash. The open spots will be marked, and I am pretty sure they are fused as well.

Damon23 · 04-12-2013, 12:09 PM

If you have a electric choke you could tie into that but I would do as mentioned above going thru the speedo cable hole and into the fuse box.

UATahoe · 04-12-2013, 12:24 PM

That sounds like the best plan. I have to run my tach wire out as well so should be easy enough to do all at once.

Redcap · 04-12-2013, 12:32 PM

Run a couple relays and a switch.

MalibuSSwagon · 04-12-2013, 01:16 PM

Your electric fans should be wired to battery power anyways, so that they still run when you shut off the truck.

O2 sensor heater should require 10 amps or less, you can get fusebox connectors and run the wire thru the C100 connecting to the fusebox.

UATahoe · 04-12-2013, 01:22 PM

I am using the painless 30115 electric fan kit. I have to run the 12v lead from the coolant temp sensor to an ignition hot 12V source.

MalibuSSwagon · 04-12-2013, 01:29 PM

ohh weird. I was thinking of an OEM setup which is ground switched.

03-25-2013, 03:43 PM	#1
UATahoe Registered User Join Date: Mar 2012 Location: Huntsville, AL Posts: 1,000	Ignition hot 12V source in the engine bay? Hey guys, just curious if you guys have some recommendations on a place to tie in to an ignition hot 12V source? Getting ready to wire up my electric fans and a new O2 sensor for my 87 R10

03-25-2013, 04:39 PM	#2
willett Another Day, Another Dollar Join Date: Nov 2008 Location: North Vancouver, BC Posts: 1,316	Re: Ignition hot 12V source in the engine bay? If I were you I would get a big constant duty solenoid ran off the battery and run the control wire off of an ign controlled port in the fuse box Posted via Mobile Device __________________ -78 K20 Cheyenne 454 long box, 4" lift, 35" MT's, '84 cab, '80 box "its hip to be square"

04-12-2013, 09:50 AM	#3
UATahoe Registered User Join Date: Mar 2012 Location: Huntsville, AL Posts: 1,000	Re: Ignition hot 12V source in the engine bay? I will look in to that. Was hoping i could find somewhere in the engine bay and not have to run all the way back in to the fuse box.

04-12-2013, 10:17 AM	#4
Jonboy Slots go on anything! Join Date: May 2003 Location: Richardson, TX Posts: 5,957	Re: Ignition hot 12V source in the engine bay? If you run it on the drivers side, it won't be that long. The O2 sensor is already pretty close to the fuse box.

04-12-2013, 10:29 AM	#5
UATahoe Registered User Join Date: Mar 2012 Location: Huntsville, AL Posts: 1,000	Re: Ignition hot 12V source in the engine bay? Roger that. The coolant sensor for the fans will be on the passenger side head but still not a big deal. I cant say i have actually looked at the fuse box yet inside the engine bay. I will look when i get home. I was planning on tieing the two 2 together into the same point. I have a wiring diagram for the truck so hopefully i can figure out which fuses are ignition driven for the 87. I am guessing i can tie in to the fuse box from the engine bay side right? Havent really fooled too much with the electrical on these yet.

04-12-2013, 11:15 AM	#6
Jonboy Slots go on anything! Join Date: May 2003 Location: Richardson, TX Posts: 5,957	Re: Ignition hot 12V source in the engine bay? Just put the wire through the speedo cable grommet, and tie into the fuse box under the dash. The open spots will be marked, and I am pretty sure they are fused as well.

04-12-2013, 12:09 PM	#7
Damon23 Registered User Join Date: Sep 2009 Location: D'ville Georgia Posts: 470	Re: Ignition hot 12V source in the engine bay? If you have a electric choke you could tie into that but I would do as mentioned above going thru the speedo cable hole and into the fuse box. __________________ Experience is something you gain when you didn't get what you wanted in the first place. No great defeat was ever just possible in the beginning.

04-12-2013, 12:24 PM	#8
UATahoe Registered User Join Date: Mar 2012 Location: Huntsville, AL Posts: 1,000	Re: Ignition hot 12V source in the engine bay? That sounds like the best plan. I have to run my tach wire out as well so should be easy enough to do all at once.

04-12-2013, 12:32 PM	#9
Redcap Registered User Join Date: May 2010 Location: Lewis County, WA Posts: 1,523	Re: Ignition hot 12V source in the engine bay? Run a couple relays and a switch. __________________ '77 K35 - 454, SM465/NP205, 4.56 D60/14bFF

04-12-2013, 01:16 PM	#10
MalibuSSwagon Registered User Join Date: Sep 2009 Location: Weare,NH Posts: 1,592	Re: Ignition hot 12V source in the engine bay? Your electric fans should be wired to battery power anyways, so that they still run when you shut off the truck. O2 sensor heater should require 10 amps or less, you can get fusebox connectors and run the wire thru the C100 connecting to the fusebox. __________________ Eric 1992 Oldsmobile Custom Cruiser 1986 Chevrolet C10\|5.3L\|TKO600\|Shortbed\|Custom Deluxe 1983 Malibu Wagon\|TPI 305\|T5 5 speed\|3.73 non-posi

04-12-2013, 01:22 PM	#11
UATahoe Registered User Join Date: Mar 2012 Location: Huntsville, AL Posts: 1,000	Re: Ignition hot 12V source in the engine bay? I am using the painless 30115 electric fan kit. I have to run the 12v lead from the coolant temp sensor to an ignition hot 12V source.

04-12-2013, 01:29 PM	#12
MalibuSSwagon Registered User Join Date: Sep 2009 Location: Weare,NH Posts: 1,592	Re: Ignition hot 12V source in the engine bay? ohh weird. I was thinking of an OEM setup which is ground switched. __________________ Eric 1992 Oldsmobile Custom Cruiser 1986 Chevrolet C10\|5.3L\|TKO600\|Shortbed\|Custom Deluxe 1983 Malibu Wagon\|TPI 305\|T5 5 speed\|3.73 non-posi



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