Won't start- please Help

[Theoriginalsilverado]

Quick question. Hooked everything up to my motor to make it run today after putting on the newly painted cab. Motor turns over with turn of the key but motor will not catch. Any idea what might be missing? There is one wire now not hooked up that I think could be the cause. I don't have any pictures so I found another similar engine bay online for reference.

I've circled the connection in question. The red wire that comes from the junction and runs to a fused connection, does anyone know what that connection is for? I have not hooked it up but I realize now that it may be a crucial link? Or not?

This has me super frustrated so any help would be greatly appreciated

[Theoriginalsilverado]

****UPDATE***************
I have pictures now. You'll see the connection that is not connected which I'm asking about.

Thanks again

****EDIT*****************
Sorry about the orientation of the pictures

[Dead Parrot]

I think that fuse is the power for the heater/AC blower motor. Other end should go to the fan relay.

Verify that with the ignition on, you have power to the distributor.

[Theoriginalsilverado]

Originally Posted by Dead Parrot

I think that fuse is the power for the heater/AC blower motor. Other end should go to the fan relay.

Verify that with the ignition on, you have power to the distributor.

Thanks for the information.
How would I go about checking the power to the distributor?

[Ozzy2013]

Take a test light or volt meter ground one end put the other lead on the ignition coil lead and see if it lights upwork your way back to the ignition switch Its real easy just take your time !Google how to test and its all available better yet buy a manual and it takes you step by step how to trouble shoot

[rich weyand]

Another question to check: Did you stab the distributor on the correct Top-Dead-Center?

There are two TDCs per revolution on the crankshaft. For the non-firing one, the rotor should be at 11:00 when looking down on it while standing in front of the truck. On the correct, firing TDC, it should be at about 5:00.

The end of the first post in this thread tells you how to find the right one.
http://67-72chevytrucks.com/vboard/s...d.php?t=689321

[hatzie]

Originally Posted by Dead Parrot

I think that fuse is the power for the heater/AC blower motor. Other end should go to the fan relay.

Yup. The other half should be an ORANGE wire to the common terminal of the blower HI relay plug on an AC equipped truck. The worst thing that'll happen right now is the blower will not run on HI.

If the other half of the fuse holder is missing or not repairable... I'd replace the fuse holder with a 15A Bussman CBC15HB circuit breaker. You'll have to terminate the wires with #10 ring terminals for the 10-12ga wire.
If you'd rather put an glass cartridge type fuse holder back in use a Bussman HFB-10 fuse holder.

Originally Posted by Dead Parrot

Verify that with the ignition on, you have power to the distributor.

From 73-78 the Backup Lamps fuse is also your ignition-coil power fuse.

If you or the PO upgraded from points to HEI you'll need to replace the 20ga Purple/Black ballast resistor wire from the bulkhead plug to the HEI distributor BAT terminal... If it hasn't already been done.
The HEI BAT wire should be much heavier 12ga and the stock color is PINK. Accel makes a BATT/TACH connector for HEI distributors # 170072. You can also get the stock single terminal style HEI BAT connector from Painless # 30809.
The ACCEL and GM HEI plugs use Delphi Packard 56 Female terminals. The bulkhead plug uses Delphi Packard 56 Male terminals.
I'd extract the terminal from the new connector and from the old ignition wire at the bulkhead plug. Then I'd make a single PINK wire that's as long as the Purple/Black wire you're replacing... with Packard 56 Male on one end and Packard 56 Female on the other. That way you don't have to install a wire with a butt splice in the middle.

If you don't have the tooling or patience to roll your own. M&H makes an HEI conversion power wire for the GM A & B-Bodies with the HEI BAT connector on one end and the bare Male Packard 56 on the other. It's M&H Part# 00510. It should work just fine on the 67-75 CK trucks too.

[Theoriginalsilverado]

Originally Posted by hatzie

Yup. The other half should be an ORANGE wire to the common terminal of the blower HI relay plug on an AC equipped truck. The worst thing that'll happen right now is the blower will not run on HI.

If the other half of the fuse holder is missing or not repairable... I'd replace the fuse holder with a 15A Bussman CBC15HB circuit breaker. You'll have to terminate the wires with #10 ring terminals for the 10-12ga wire.
If you'd rather put an glass cartridge type fuse holder back in use a Bussman HFB-10 fuse holder.





From 73-78 the Backup Lamps fuse is also your ignition-coil power fuse.

If you or the PO upgraded from points to HEI you'll need to replace the 20ga Purple/Black ballast resistor wire from the bulkhead plug to the HEI distributor BAT terminal... If it hasn't already been done.
The HEI BAT wire should be much heavier 12ga and the stock color is PINK. Accel makes a BATT/TACH connector for HEI distributors # 170072. You can also get the stock single terminal style HEI BAT connector from Painless # 30809.
The ACCEL and GM HEI plugs use Delphi Packard 56 Female terminals. The bulkhead plug uses Delphi Packard 56 Male terminals.
I'd extract the terminal from the new connector and from the old ignition wire at the bulkhead plug. Then I'd make a single PINK wire that's as long as the Purple/Black wire you're replacing... with Packard 56 Male on one end and Packard 56 Female on the other. That way you don't have to install a wire with a butt splice in the middle.

If you don't have the tooling or patience to roll your own. M&H makes an HEI conversion power wire for the GM A & B-Bodies with the HEI BAT connector on one end and the bare Male Packard 56 on the other. It's M&H Part# 00510. It should work just fine on the 67-75 CK trucks too.

Wow! Thanks for all the information. It makes more sense now, I was also wondering about that orange wire with the snap on top style connector.

But the second part of your info has me confused, as the truck is entirely stock. All I've done is take it apart and replace and worn parts. The truck was in my family it's entire life and I can guarantee that the first one to turn a wrench on it for something other than general maintenance was me. I thought the truck had HEI from the factory?

Thanks again

[Theoriginalsilverado]

Originally Posted by rich weyand

Another question to check: Did you stab the distributor on the correct Top-Dead-Center?

There are two TDCs per revolution on the crankshaft. For the non-firing one, the rotor should be at 11:00 when looking down on it while standing in front of the truck. On the correct, firing TDC, it should be at about 5:00.

The end of the first post in this thread tells you how to find the right one.
http://67-72chevytrucks.com/vboard/s...d.php?t=689321

Thanks a lot! I'll be sure to give it a try

[hatzie]

Originally Posted by Theoriginalsilverado

Wow! Thanks for all the information. It makes more sense now, I was also wondering about that orange wire with the snap on top style connector.

But the second part of your info has me confused, as the truck is entirely stock. All I've done is take it apart and replace and worn parts. The truck was in my family it's entire life and I can guarantee that the first one to turn a wrench on it for something other than general maintenance was me. I thought the truck had HEI from the factory?

Thanks again

Without the year in your posts I was left to guess from cues in the pictures. Capillary oil gauge tube and an AGC fuse for the AC blower in the pictures places it as a 76 or before. Most 75 & all later came stock with HEI.
73 & 74 would've come from the factory with breaker points. I had a 50:50 chance of it being a 73 or 74.

[Theoriginalsilverado]

Originally Posted by hatzie

Without the year in your posts I was left to guess from cues in the pictures. Capillary oil gauge tube and an AGC fuse for the AC blower in the pictures places it as a 76 or before. Most 75 & all later came stock with HEI.
73 & 74 would've come from the factory with breaker points. I had a 50:50 chance of it being a 73 or 74.

Since my truck is a 75, where does that leave me?

Thanks again for sharing your wealth of knowledge

[barry1982]

Do you have a coil mounted on your intake manifold? No coil... you have an HEI. (HEI coil mounted in dist cap) You did not specify which "worn parts" you changed? Did you have the distributor pulled out ? Change the timing chain? The engine requires spark, fuel and to be in time to run. If you never messed with the dist or timing chain, your timing should still be fine. That leaves spark or fuel. Pull a spark plug, reattach to spark plug wire , place plug against clean metal on engine an get a helper to crank engine. If you see plug spark , you have eliminated that. Pour a small amount of gas directly into carb and crank. If engine starts than dies, you are not getting fuel to carb. If you have spark, and have fuel and it still won't run, chances are you have a timing issue. I can explain how you can check this if you like.

[hatzie]

Originally Posted by Theoriginalsilverado

Since my truck is a 75, where does that leave me?

Thanks again for sharing your wealth of knowledge

If it's '75 or later it's exceedingly unlikely that it's not HEI. Ignore my comments on the resistor wire... It only applies to 73 & 74...
The HEI cap is @ 4" in diameter with the coil mounted in the cap and the power and tach connections on a rectangular projection off side of the cap.
A breaker points cap is more like 2-3/4" diameter, has a coil wire tower dead center of the top, and it has a square sheet metal door in the side to access the dwell adjustment screw on the points. When I was a tenager in the early 80's I usually blew through a set of points in 7,000-10,000 miles or so on my 74 C30. When I discovered HEI was a cheap drop in replacement the points went away. I doubt you have one of these on a 1975.

No start is either fuel or fire.
Get a scrupulously clean tiny funnel, a clean measuring cup or tablespoon, and clean fresh gasoline. Pull the top off the air cleaner. Fit the tiny funnel into the bowl vent. Then pour just under 2oz (1/4 cup or 2 tablespoons) of clean fuel down the bowl vent tube to fill the carburetor float bowl.

Before you crank it put the air cleaner back on with the wingnut. It can backfire for any number of reasons and you'll want the air cleaner in place to arrest most backfire fires.
With a filled float bowl and ignition fire she should crank right up. If the fuel pump is just having issues priming the fuel lines from the tank it'll probably run nice then stumble and then run.

If she doesn't fire up with fuel in the float bowl you have an ignition problem.
Get out your digital multimeter. Check for 12volts from the PINK (BAT) HEI power wire off the distributor cap to a clean area on the engine with the ignition switched on.
If you have no fire and you have 12 volts at the HEI power wire check that you still have volts when the key is in the crank position.
Check for fire with an inline spark tester. If it has fire check the timing settings. It's very easy to install the distributor 180° out from TDC on #1.
No fire... Ohm out the coil with your meter. http://www.hotrodders.com/forum/test...tml#post727460
While you have the cap off check over the pigtail that connects the cap to the ignition module inside the distributor. If the wires are cracked or otherwise damaged you can replace the pigtail and condenser with an AC Delco 19207437 for around $20.