70 C10 Red Bat Wire on Ignition Switch getting super hot - The 1947 - Present Chevrolet & GMC Truck Message Board Network

bgood70 · 11-20-2018, 05:04 PM

I have a 1970 C10 with Autowire retrofit wiring harness. Been fine for a couple years. Now the red wire on the ignition switch is getting super hot. Only right near the switch go back a few inches and feels fine.

I have relays for my electrical fans and checked them to make sure they were good.

I recently installed Fitech fuel injection with electric fuel pump and a 4l60e Transmission using the EZ TCU controller. I am not sure if these would cause addtional load on that paticular wire. I though it might be the ignition switch going bad.

**LockDoc** · 11-20-2018, 05:11 PM

Quote:

Originally Posted by bgood70

I have a 1970 C10 with Autowire retrofit wiring harness. Been fine for a couple years. Now the red wire on the ignition switch is getting super hot. Only right near the switch go back a few inches and feels fine.

I have relays for my electrical fans and checked them to make sure they were good.

I recently installed Fitech fuel injection with electric fuel pump and a 4l60e Transmission using the EZ TCU controller. I am not sure if these would cause addtional load on that paticular wire. I though it might be the ignition switch going bad.

Unplug the connector on the back of the switch and see if the plastic is melted on the connector. It sounds like you might have a bad connection on the wire in the plug or the contact inside the switch on that terminal.

LockDoc

bgood70 · 11-20-2018, 05:38 PM

yes it was melted and I ordered new pigtail pulled the wire connectors out and put into new pastic housing. Maybe I should splice in the new pigtail wires in. I was trying to avoid splicing. I have also ordered a new ignition switch in case it is something with the connectors on it.

Andy4639 · 11-22-2018, 12:05 PM

Did you run the fuel pump off a relay? If not I would.
I have had this same problem in the past. I have yet to find the answer other than just replacing the connector. It hasn't done it since though so it could be just a wear problem in these truck.

Stormin08 · 11-26-2018, 07:27 PM

the fitech has a built in relay for fuel pump (if i recall), mine is connected to the factory wiring connection, then straight to pump.

LH Lead-Foot · 11-29-2018, 04:01 PM

These older trucks had very few devices requiring less current. Many came with alternators that produced 40 amps or 60 amp. If the ignition switch is overheating at the connector, before doing this repair again, I would check to total current passing thru the switch.
The use of relays to control many circuits take the current down at the ignition switch, fixing your problem long term.

Buy or barrow an inductive amp clamp to attach to a DMM. Read the instructions so you can understand the reading for actual current. Turn on as many electrical systems as you can, from wipers, lights, radio, heater, etc. Take a reading at the "Red" battery circuit at the ignition switch.

As posted, run the fuel pump, headlights, stereo and any other high amperage toys using relays. A fuse can be used to protect each of these relays and the circuits they control.

I think a 10 year old Silverado will have roughly 28 relays, under the hood, left dash, right dash, etc.

11-20-2018, 05:04 PM	#1
bgood70 Registered User Join Date: Feb 2009 Location: Jacksonville Fl Posts: 180	70 C10 Red Bat Wire on Ignition Switch getting super hot I have a 1970 C10 with Autowire retrofit wiring harness. Been fine for a couple years. Now the red wire on the ignition switch is getting super hot. Only right near the switch go back a few inches and feels fine. I have relays for my electrical fans and checked them to make sure they were good. I recently installed Fitech fuel injection with electric fuel pump and a 4l60e Transmission using the EZ TCU controller. I am not sure if these would cause addtional load on that paticular wire. I though it might be the ignition switch going bad. __________________ 70 C-10 SWB 350/700r4 Good 70 SWB Build 72 GMC Sprint SP Custom 350/Turbo300

11-20-2018, 05:38 PM	#3
bgood70 Registered User Join Date: Feb 2009 Location: Jacksonville Fl Posts: 180	Re: 70 C10 Red Bat Wire on Ignition Switch getting super hot yes it was melted and I ordered new pigtail pulled the wire connectors out and put into new pastic housing. Maybe I should splice in the new pigtail wires in. I was trying to avoid splicing. I have also ordered a new ignition switch in case it is something with the connectors on it. __________________ 70 C-10 SWB 350/700r4 Good 70 SWB Build 72 GMC Sprint SP Custom 350/Turbo300

11-22-2018, 12:05 PM	#4
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,936	Re: 70 C10 Red Bat Wire on Ignition Switch getting super hot Did you run the fuel pump off a relay? If not I would. I have had this same problem in the past. I have yet to find the answer other than just replacing the connector. It hasn't done it since though so it could be just a wear problem in these truck. __________________ 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.

11-26-2018, 07:27 PM	#5
Stormin08 Registered User Join Date: Sep 2018 Location: Moss Bluff, LA Posts: 381	Re: 70 C10 Red Bat Wire on Ignition Switch getting super hot the fitech has a built in relay for fuel pump (if i recall), mine is connected to the factory wiring connection, then straight to pump.

11-29-2018, 04:01 PM	#6
LH Lead-Foot Registered User Join Date: Jan 2018 Location: Omaha, NE. Posts: 214	Re: 70 C10 Red Bat Wire on Ignition Switch getting super hot These older trucks had very few devices requiring less current. Many came with alternators that produced 40 amps or 60 amp. If the ignition switch is overheating at the connector, before doing this repair again, I would check to total current passing thru the switch. The use of relays to control many circuits take the current down at the ignition switch, fixing your problem long term. Buy or barrow an inductive amp clamp to attach to a DMM. Read the instructions so you can understand the reading for actual current. Turn on as many electrical systems as you can, from wipers, lights, radio, heater, etc. Take a reading at the "Red" battery circuit at the ignition switch. As posted, run the fuel pump, headlights, stereo and any other high amperage toys using relays. A fuse can be used to protect each of these relays and the circuits they control. I think a 10 year old Silverado will have roughly 28 relays, under the hood, left dash, right dash, etc. __________________ Removed



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