1990 c1500 keeps cranking on its own. HELP!

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.

limited_obs

Newbie
Joined
Dec 22, 2019
Messages
13
Reaction score
4
Location
illinois
Hello everyone. Just recently purchased a 1990 c1500 with the 5.7L everything was all good up until a couple days ago. So intermittently I go and start the truck up (stored for winter) and it turns over and does not start and when I go to key it off it just keeps cranking on it’s own?? Anyone ever experience this? I’m not sure where to start? Maybe a faulty ignition switch I would think? Any help would be greatly appreciated
 

someotherguy

I'm Awesome
Joined
Sep 28, 2013
Messages
9,784
Reaction score
14,138
Location
Houston TX
Tilt column wobbly? (try lifting it up and down) - if so then the bolts holding the tilt knuckle together are loose, super common problem; on the 94-older column like yours the ignition tumbler moves an arrangement of parts that operate a rod running down the outside of the column tube to the actual ignition switch. Slop in the tilt mechanism can interfere with the operation of this.

Richard
 

limited_obs

Newbie
Joined
Dec 22, 2019
Messages
13
Reaction score
4
Location
illinois
i just checked my tilt column, there is very little play up and down. Do you think this would have to do with why it keeps cranking on its own even after I key it off? If so any tips or links on how to repair this problem?
 

jamesdking

Newbie
Joined
Mar 9, 2018
Messages
33
Reaction score
24
Location
Montana
I had this problem to much of my confusion. It exploded one of the starters! No BS! I’d look at your big cable from the battery to your starter. Mine had cracks in the insulation causing a short near the starter posts.
 

jamesdking

Newbie
Joined
Mar 9, 2018
Messages
33
Reaction score
24
Location
Montana
Also after I replaced it I accidentally let it touch the exhaust manifold causing another short. It was truly a troublesome cable for me by the time I figured it all out. Good luck!
 

limited_obs

Newbie
Joined
Dec 22, 2019
Messages
13
Reaction score
4
Location
illinois
Also after I replaced it I accidentally let it touch the exhaust manifold causing another short. It was truly a troublesome cable for me by the time I figured it all out. Good luck!
Would your also not start? Because when mine acts up and keeps cranking it does not start. So your saying your starter cable going from battery to starter was shorted and that’s why it kept cranking?
 

jamesdking

Newbie
Joined
Mar 9, 2018
Messages
33
Reaction score
24
Location
Montana
As best as I can remember on those early models there’s the starter switch safety switch by the clutch, the ignition in the column, and the heavy 4 ga wire from the battery to the starter sel. You most likely have a short in one of those or the starter is going out. The constant wire from the battery is poorly shielded from the exhaust manifold and when I pulled it out the insulation flaked off it, all, over exposing several points of short that caused weird starting issues.
 

HotWheelsBurban

Gotta have 4 doors..... Rawhide, TOTY 2023!
Joined
Sep 18, 2019
Messages
9,685
Reaction score
17,564
Location
Houston, Texas
The small terminal on the starter solenoid is very close to the main terminal that the battery cable hooks to. If that cable end lug touches the small terminal, or the wire to the small terminal is touching the main terminal, it'll trigger the starter to crank whenever the battery is hooked up. This happened to me on my R2500 square body Burb, scared the hell outta me. These two terminals are sometimes separated by a ridge on the plastic cap of the solenoid; not all solenoids are made this way. Compounding the problem is that there's not much room to maneuver unless the truck is on a lift. But I agree with the other posters that you definitely need to look at the cables. They can be corroded badly and it's not visible, and the factory loop hold downs are there to keep the cable away from the exhaust manifold and the suspension. They're a bother to put the cable through but worth the effort to keep your cable safe. On my 99 Burb there's 2 positive cables and the factory replacement ones are over $200. I had a battery shop make a replacement one for me for a lot cheaper. Good luck, let us know what finally fixed it
 
Top