Help, truck just died on me... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Jobe72 · 10-25-2011, 04:51 PM

My 1972 GMC just died on me on the way back to the office today from a job site. It's getting fuel, cranks over but won't start. I checked all the wires, hoses, etc that I could see and nothing out of place. I'm guessing ignition issues since it just died while driving. It's a 350/350 combo and converted to HEI. I just replaced the cap, coil, rotor, wires, etc back in March or so.

Thoughts?

Thanks, had to leave it on the side of the road and get a ride back to the office (had 2 coworkers with me) and waiting for the tow truck to bring it home.

Thanks!

C20-67_N_MO · 10-25-2011, 04:55 PM

Get it back home and pull a spark plug wire and see if it's getting spark.

Then go from there.

Good luck.

Gene · 10-25-2011, 05:00 PM

Check batt. Wire that plugs into hei cap. Mine came loose did the same thing.
Posted via Mobile Device

Jobe72 · 10-25-2011, 05:52 PM

I'll check spark when I get home, and checked the hei wires when I was there but you never know...can't wait to get home and get busy diagnosing so I can get to work in the morning!

Jobe72 · 10-26-2011, 12:58 PM

Ended up being a fried HEI coil...as in the actual wires were burned! Don't know how that happened...back on the road!

splehigh · 10-26-2011, 01:08 PM

I was going to say the module. Glad you got it fixed

cdowns · 10-26-2011, 02:44 PM

poor connections and poor gounding cause heat and wires melting

Jobe72 · 10-26-2011, 03:01 PM

Tonight I'm going through all of my connections when I can get my truck out in my shop.

cleszkie · 10-26-2011, 06:20 PM

Make sure you are sending a full 12 volts to the HEI. If you use the factory power lead that your truck came with, you will be sending less than 12 volts since the factory wire was a resistance wire designed for use with the points system/ballast resistor. The HEI will run for a while with the lower voltage, but will eventually fry the module and/or the cap and rotor itself. Ask me how I know...

ChevLoRay · 10-26-2011, 11:03 PM

Make sure you use the heat sink compound that transfers heat from the module to the breaker plate. If you don't, it will cook the module.

10-25-2011, 04:51 PM	#1
Jobe72 Registered User Join Date: Mar 2010 Location: Austin, TX Posts: 299	Help, truck just died on me... My 1972 GMC just died on me on the way back to the office today from a job site. It's getting fuel, cranks over but won't start. I checked all the wires, hoses, etc that I could see and nothing out of place. I'm guessing ignition issues since it just died while driving. It's a 350/350 combo and converted to HEI. I just replaced the cap, coil, rotor, wires, etc back in March or so. Thoughts? Thanks, had to leave it on the side of the road and get a ride back to the office (had 2 coworkers with me) and waiting for the tow truck to bring it home. Thanks! __________________ 1972 GMC Sierra LWB (Aquafresh) 1962 Cadillac Convertible 1962 Cadillac Sedan project

10-25-2011, 04:55 PM	#2
C20-67_N_MO Champagne Taste on Beer Budget Join Date: Dec 2008 Location: High Ridge, Missouri Posts: 2,190	Re: Help, truck just died on me... Get it back home and pull a spark plug wire and see if it's getting spark. Then go from there. Good luck. __________________ Coming Soon: Project 1970 Country Truck

10-25-2011, 05:00 PM	#3
Gene Registered User Join Date: Aug 2002 Location: Muskogee, Oklahoma Posts: 2,914	Re: Help, truck just died on me... Check batt. Wire that plugs into hei cap. Mine came loose did the same thing. Posted via Mobile Device __________________ 1971 SWB 4X4 Build BOARD MEMBER #5448 BOOMER SOONER!!!!

10-25-2011, 05:52 PM	#4
Jobe72 Registered User Join Date: Mar 2010 Location: Austin, TX Posts: 299	Re: Help, truck just died on me... I'll check spark when I get home, and checked the hei wires when I was there but you never know...can't wait to get home and get busy diagnosing so I can get to work in the morning! __________________ 1972 GMC Sierra LWB (Aquafresh) 1962 Cadillac Convertible 1962 Cadillac Sedan project

10-26-2011, 12:58 PM	#5
Jobe72 Registered User Join Date: Mar 2010 Location: Austin, TX Posts: 299	Re: Help, truck just died on me... Ended up being a fried HEI coil...as in the actual wires were burned! Don't know how that happened...back on the road! __________________ 1972 GMC Sierra LWB (Aquafresh) 1962 Cadillac Convertible 1962 Cadillac Sedan project

10-26-2011, 01:08 PM	#6
splehigh Registered User Join Date: Nov 2008 Location: Glenville, Pa Posts: 445	Re: Help, truck just died on me... I was going to say the module. Glad you got it fixed __________________ http://67-72chevytrucks.com/vboard/s...d.php?t=355153 Last edited by splehigh; 10-26-2011 at 01:21 PM.

10-26-2011, 02:44 PM	#7
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Help, truck just died on me... poor connections and poor gounding cause heat and wires melting __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

10-26-2011, 03:01 PM	#8
Jobe72 Registered User Join Date: Mar 2010 Location: Austin, TX Posts: 299	Re: Help, truck just died on me... Tonight I'm going through all of my connections when I can get my truck out in my shop. __________________ 1972 GMC Sierra LWB (Aquafresh) 1962 Cadillac Convertible 1962 Cadillac Sedan project

10-26-2011, 06:20 PM	#9
cleszkie Registered User Join Date: Feb 2003 Location: Santa Ana, CA Posts: 2,191	Re: Help, truck just died on me... Make sure you are sending a full 12 volts to the HEI. If you use the factory power lead that your truck came with, you will be sending less than 12 volts since the factory wire was a resistance wire designed for use with the points system/ballast resistor. The HEI will run for a while with the lower voltage, but will eventually fry the module and/or the cap and rotor itself. Ask me how I know...

10-26-2011, 11:03 PM	#10
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	Re: Help, truck just died on me... Make sure you use the heat sink compound that transfers heat from the module to the breaker plate. If you don't, it will cook the module. __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.



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