Tech Tip: Diagnosing a Slow Cranking Starter or No Crank at All

Tech Tip: Diagnosing a Slow Cranking Starter or No Crank at All

A slow cranking starter or no crank at all may be caused by a faulty ground that prevents full voltage to the starter motor. Most people assume the starter is grounded because it is bolted to the engine. However, that does not mean it's grounded properly. The combination of road dirt, salt corrosion, engine heat and vehicle age can prevent a good starter-to-engine ground (metal-to-metal contact).

Application:
All vehicles with 12-volt starter motors.

Problem:
Slow cranking starter or no crank at all.

Cause:
Possible faulty ground that prevents full voltage to the starter motor.

Solution:
Most people assume the starter is grounded because it is bolted to the engine. However, that does not mean it’s grounded properly. The combination of road dirt, salt corrosion, engine heat and vehicle age can prevent a good starter-to-engine ground (metal-to-metal contact). A good ground path should measure zero voltage loss (no voltage drop). It is possible that a loose starter, corroded surfaces or faulty ground cables are stealing cranking voltage from the motor. If you just replaced the starter and it cranks slow or not at all, test for a proper ground by using a voltmeter – test, don’t guess!

Test Procedure:
Safely disable the ignition or fuel pump so the engine won’t start. Connect one voltmeter lead to a clean spot on the starter case, and then the other voltmeter lead to the negative battery terminal. Set the meter to the one volt DC scale. With key-on-engine-off, voltage must not exceed 0.1 volts. Now crank the engine for 10 seconds maximum while watching the meter readout. The voltmeter reading should not exceed 0.5 volts. If the voltage drop is greater, look for a ground cable problem or an improperly grounded starter motor as described above.

Tech Tip courtesy of CARDONE.

For additional information on products offered by CARDONE, visit www.cardone.com.

You May Also Like

Tool Time Podcast: Clore Automotive

Jim O’Hara from Clore Automotive joins Nadine Battah and Eric Garbe.

TechShop’s Tool Time Podcast Series highlights tool and equipment trends, combined with an educational focus on technology that brings solutions to shop owners and techs as they address the growing complexity of vehicle repair.

In this episode, Tech Shop Editor Nadine Battah and Babcox Media's ASE Certified Master Technician Eric Garbe sit down with Jim O'Hara from Clore Automotive.

TechShop, ShopOwner Offer $50 For Good Guesses

Guess the Tool for a chance at cold hard cash!

GM, Honda Begin Volume Production of Fuel Cell Systems

GM and Honda will produce fuel cells that will be two-thirds less expensive compared to Honda’s 2019 Clarity fuel cell.

Toyota Bringing Battery EV Production to Kentucky

It will invest $1.3 billion at its flagship Kentucky facility for future electrification efforts, including assembly of an all-new, three-row battery electric SUV for the U.S. market.

Repairify Announces Executive Leadership Changes

The company has named Craig Edmonds as president of asTech among other executive appointments.

Other Posts

New Hyundai/Kia Air Skirt Helps to Maximize EV Range

The Active Air Skirt (AAS) helps improve driving range and stability of EVs, the companies said.

StoreDot Introduces Extreme Fast Charging Concept Vehicle

The company’s I-Beam XFC includes a proprietary “100in5” cell technology, which enables charging 100 miles of range in just five minutes.

TPMS: Are Retrofits in Your Future?

Installing a retrofit kit can be performed with the tools and equipment you already own and use on a daily basis.

Tire tread
Clarios, Altris Partner on Low-Voltage Sodium-Ion Batteries

The companies will develop a Na-ion battery with a potential of up to 60 volts to support automotive applications.