Ignition issues, Truck Continues Running After Twisting Key to Off Position

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

gill finn

Junior Member
Joined
Mar 31, 2023
Posts
10
Reaction score
8
Location
Massachusetts
First Name
Graham
Truck Year
1984
Truck Model
C20
Engine Size
350
Hello, slowly but surely I'm ironing out these little bugs. I went to shut the truck off the other day and it continues running. Not dieseling, but just idling smoothly, I then turn the key back to the running position and back again, I can hear the engine kind of beginning to lose a little power, almost a volume loss, I repeat, then it eventually turned off. It happened again today, but it doesn't do it all the time. Any ideas? Thanks a lot!
 

squaredeal91

Full Access Member
Joined
Mar 10, 2023
Posts
1,806
Reaction score
3,167
Location
Cave junction Oregon
First Name
Greg bush
Truck Year
1991 SB
Truck Model
K30
Engine Size
5.9 Cummins 12 valve
Ignition switch down on the column comes to mind with those symptoms. Sometimes they come apart
 

gill finn

Junior Member
Joined
Mar 31, 2023
Posts
10
Reaction score
8
Location
Massachusetts
First Name
Graham
Truck Year
1984
Truck Model
C20
Engine Size
350
Thanks, it wouldn't happen to be the commutator interrupter switch would it? I'm trying to narrow it down.
 

RanchWelder

Full Access Member
Joined
Jan 14, 2023
Posts
634
Reaction score
921
Location
Earth
First Name
--------
Truck Year
87
Truck Model
Blazer
Engine Size
355ci
Remove the 4 bolts under your column and carefully drop the assembly.
The wheel will fall just enough to expose a white, gray, black or blue plastic mechanism which connects to a rod up your column.
You can search for the column diagram for the year of your truck.

The switches get dirt into the slider and stick open or break from dried out plastic.
Here's a non-tilt in black:
You must be registered for see images attach


Make certain the connector matches the old unit and tilt configuration is the one you need or the parts store might not take it back. The slots are for adjustment. Try to locate it where it was. Lot's of pics...

I have successfully pulled the old unit apart and lubed the ball bearings and terminals internally, in order to get the truck up and running. They might go flying though... (Last resort only.)

There's nothing like a new Standard Motor Switch, so buy the good stuff, not the junk.

Using a gob of dielectric grease on the electrical connector and where the rod slides the internals, before you put it back. This will lube and seal your ignition switch for a good long while. The rod up the column has to insert and drive the switch. Take your time and make certain the high beam switch is adjusted correctly and functions properly before you button everything up. It is easy to get the high beam rod flipped and then it doesn't work, so take a few pictures before you get into it.

The steel edges will be sharp. Try not to give blood.
I have made this repair in the dead of summer... find some shade.

If the key still gives you a tough time, there's a gear made of plastic inside your column which drives the rod.
If it's broken or full of dirt, the OEM cylinder and a new drive gear might be next.

Have fun!
 
Last edited:

gill finn

Junior Member
Joined
Mar 31, 2023
Posts
10
Reaction score
8
Location
Massachusetts
First Name
Graham
Truck Year
1984
Truck Model
C20
Engine Size
350
Wow! Thanks a lot, I'll let you know how it goes, this is what I thought it might be as I've now watched a few videos. Oh well, it's all participation I guess! Thanks again!
 

Forum statistics

Threads
42,158
Posts
910,295
Members
33,655
Latest member
djisurfli
Top