This is for glow plugs without a pressure sensor...
How to Test Glow Plugs Without a Test Meter...
My diesel Won't start when it's cold? There's white smoke coming from the exhaust... It starts OK when the engine is warm? Are the glow plugs working, can I test glow plugs with jump leads and wire? Yes...
For more information, see: [ Ссылка ]
Other Videos:
- With a test meter: [ Ссылка ]
If you need parts, try...
Glow Plugs - (UK) - [ Ссылка ]
Glow Plugs - (USA) - [ Ссылка ]
Test Meter (Multimeter) - (UK) - [ Ссылка ]
Multimeter (Test Meter) - (USA) - [ Ссылка ]
Glow Plug Removal Tools - (UK) - [ Ссылка ]
Glow Plug Removal Tools - (USA) - [ Ссылка ]
Jump Leads - (UK) - [ Ссылка ]
Jumper Cables - (USA) - [ Ссылка ]
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How to test without using multimeter.
– How to Fix?
Petrol engines start with the assistance of a spark from a spark plug to ignite the fuel. Whereas diesels start using the compression of the fuel mixture. However, diesels don’t like starting when cold. Hence diesel engines are fitted with glow plugs that heat the air fuel mix to aid starting when cold.
If a diesel engine is running well and starts easily when the engine is warm, but won’t start when cold, (or takes ages to get it started when cold). It could be an issue with the glow plugs, the glow plug system (glow plug module, relay, or voltage supply).
Diesel Cold Starting – Fault Symptoms
The engine turns over at a reasonable speed (it’s not slow cranking), but the engine won’t start?
The engine starts, but only after some time (and multiple attempts)?
White smoke is seen from the exhaust (unburnt fuel).
When the engine is warm, it starts easily.
You may see white smoke from the exhaust whilst trying to start the engine and for a short while when the engine starts (unburnt fuel).
Diesel Cold Starting – The Causes
If you see white smoke coming from the exhaust (unburnt fuel), after several starting attempts…
Some, or all of the glow plugs may have failed?
There maybe no voltage supplied to the glow plugs?
The glow plugs may switch off too soon. The timer (or control module) could be defective?
Diesel Cold Starting – Things to Check
The glow plug relay:
The glow plug timer (or control module):
The glow plugs:
Note: The glow plug relay is sometimes a separate item, but it can also be incorporated inside the glow plug module (circuit card)?
Testing Glow Plugs Without a Voltmeter (Multimeter): There are some easy checks you can carry out, using a:
- Vehicle battery, or suitable earth (-ve).
- A jump lead.
- A piece of insulated wire.
The following tests can be carried out:
- Is there a Circuit (When Fitted)?
- Does the Glow Plug Work (When Removed)?
- Does the Relay and Timer Work?
Safety Precautions:
Do not short the battery connections, (or yourself across the battery, it could give you a shock!) i.e. Between the live (+ve) and the earth, or bodywork (-ve). 12 volts is not usually enough to kill you, but batteries larger than 12v may do? Hydrogen gas given off by the battery can ignite, causing an explosion. Sending bits of battery and acid everywhere…
Please refer to the vehicle manual, as each vehicle may be slightly different.
