Ignition woes - switch needed? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**GMCNUT** · 05-29-2019, 10:35 AM

I don't know why, but when its cold or started for the first time, my 72 blazer ignition has started hanging when I hit the key and the starter will turn over and over and over a thousand times unless the motor starts or I disco the battery. When hot, its started deciding not to crank at all - flip the switch and nothing happens like its totally disconnected from power. After it cools down, seems to start fine. Assumed at first this was a starter solenoid issue, so I replaced that with a brand new one only to see it act the very same. So turned my attention to the ignition switch and replaced it with a same switch spare I had laying around from a junk yard truck, and it is still doing the same thing. So I assume the junkyard ignition switch was as bad as the one I swapped it out with? New solenoid? Can't be the starter itself I would't think because it waits for the ignition to be turned on to make the solenoid jump out - the solenoid would work regardless of the starter working and thats not occurring so it has to be the switch itself - right?
So, assuming all of you agree the switch must be as bad as the one I removed, Ebay shows about 10 different ignition switches and each seller claims their switch is correct for 67-72 - part numbers I see are:
1116695, 1116704, 1116688, 1116711 and on and on. Does anyone really know what GM part # the ignition switch is supposed to be for a 72 Blazer w/ normal 350 V8 / Automatic / CST / etc?

**DeadheadNM** · 05-29-2019, 11:51 AM

This looks like the real deal here: http://67-72chevytrucks.com/vboard/s...d.php?t=787220

**A1971Blazer** · 05-29-2019, 02:19 PM

be sure to check the connector that plugs into the switch...it can short in there and cause the starter to run on like you are describing..the purple wire is what energizes the solenoid...check it for a short as well....could be shorting intermittently in that circuit...

05-29-2019, 10:35 AM	#1
GMCNUT Senior Member Join Date: Jun 2007 Location: Arab Alabama Posts: 1,809	Ignition woes - switch needed? I don't know why, but when its cold or started for the first time, my 72 blazer ignition has started hanging when I hit the key and the starter will turn over and over and over a thousand times unless the motor starts or I disco the battery. When hot, its started deciding not to crank at all - flip the switch and nothing happens like its totally disconnected from power. After it cools down, seems to start fine. Assumed at first this was a starter solenoid issue, so I replaced that with a brand new one only to see it act the very same. So turned my attention to the ignition switch and replaced it with a same switch spare I had laying around from a junk yard truck, and it is still doing the same thing. So I assume the junkyard ignition switch was as bad as the one I swapped it out with? New solenoid? Can't be the starter itself I would't think because it waits for the ignition to be turned on to make the solenoid jump out - the solenoid would work regardless of the starter working and thats not occurring so it has to be the switch itself - right? So, assuming all of you agree the switch must be as bad as the one I removed, Ebay shows about 10 different ignition switches and each seller claims their switch is correct for 67-72 - part numbers I see are: 1116695, 1116704, 1116688, 1116711 and on and on. Does anyone really know what GM part # the ignition switch is supposed to be for a 72 Blazer w/ normal 350 V8 / Automatic / CST / etc? __________________ My Projects and Toys - All 100% Stock 1972 CST "Highlander" Blazer - 350 auto, PS, PB, A/C, Tilt, Tach, AM/FM & Positraction 1966 Chevy SWB Fleetside BBW Custom Cab, #'s matching 327 V8 & Powerglide, factory deluxe heat, PS, PB, Tinted Glass, sway bar 1961 Chevy SWB Fleetside BBW Custom Cab #'s matching 283 V8 & Powerglide w/ uber-rare Cool-Pack A/C, factory PB, deluxe heat, Clock 1961 GMC K1000 4x4 SWB w/ BBW, Custom Cab and numbers matching 305D V6 engine & 4 spd 1960 GMC SWB Fleetside BBW Custom Cab #'s matching 305A V6 & Hydramatic, factory PB, Clock, Tach, Compass, Hood Jet 1959 Chevy SWB Fleetside BBW Custom Cab w/ rare stainless bed trim, #'s matching 283 V8 & Hydramatic, Deluxe Heat, radio, spotlight 1958 Chevy Cameo #'s matching 283 V8 & Hydramatic, radio, window washers, Factory PB 1958 GMC BBW SWB Fleetside Custom Cab, #'s matching 336 V8 Hydramatic, Factory PS, PB, Clock, RSD, Deluxe Heat & Hood Jet 1957 GMC Suburban Pickup (GMC's Cameo) #'s matching 347 V8 Hydramatic, uber-rare vacuum ashtray, Factory PS, PB, Clock, RSD, Hood Jet 1956 Chevy 3800 1 ton w/ rare 9 ft stepside bed, factory 265 V8 w/ Hydramatic, factory PB, Custom Cab, deluxe heat, spotlight and hood jet.

05-29-2019, 11:51 AM	#2
DeadheadNM Carpe manana Join Date: Dec 2010 Location: Eau Claire, WI Posts: 12,280	Re: Ignition woes - switch needed? This looks like the real deal here: http://67-72chevytrucks.com/vboard/s...d.php?t=787220 __________________ 1972 K5 CST Highlander Blazer: http://67-72chevytrucks.com/vboard/s...d.php?t=708547 1972 K20 Cheyenne Super: http://67-72chevytrucks.com/vboard/s...d.php?t=528308 Members met: ORANGBLAZ, 2003 silverado, MikeCofield, BB72CHEVKT, Duncan&Son, Sameyrasmea72, THENEWMEXICAN, HotRod C/10, brianthelion02, Sport/Truck, ryanroo, michael bustamante, Dirt's72, Already Gone, WestButteTruck, 57taskforce, Moreyel, painterljp, AASmedic, SoCoC10, Lumaestas, carbuff382, Chevyland

05-29-2019, 02:19 PM	#3
A1971Blazer Senior Member Join Date: Nov 2013 Location: East Tennessee Posts: 2,107	Re: Ignition woes - switch needed? be sure to check the connector that plugs into the switch...it can short in there and cause the starter to run on like you are describing..the purple wire is what energizes the solenoid...check it for a short as well....could be shorting intermittently in that circuit... __________________ 1967 C10 Step side 1968 C10 Step side 1970 Chevrolet K/5 Blazer 1972 Chevrolet K/5 Blazer .............



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