300Tdi Defender won’t start when glow plugs are on

B

bojackhorse

New Member

Posts

4

Location

Austria

• Dec 17, 2023

• #1

I have a strange issue where the starter motor won’t do anything whilst the glow plug relay is on. If I wait until after then it works or if I disconnect the glow plug fuse then it works straight away. I’ve checked the engine to chassis to battery straps and they seem fine. Any ideas?

 

julianf

Well-Known Member

Posts

2,337

Location

Devon, UK

• Dec 17, 2023

• #2

My guess would be a faulty relay.

Hypothesis - volt drop from the plugs stops the relay (I'm talking the cube things, not the solenoid) from being able to energise properly.

I mean it's just a guess, but thats what I'd go with first.

 

boguing

Well-Known Member

Full Member

Posts

10,476

Location

A bit sarf of Dorking

• Dec 18, 2023

• #3

julianf said:

My guess would be a faulty relay.

Hypothesis - volt drop from the plugs stops the relay (I'm talking the cube things, not the solenoid) from being able to energise properly.

I mean it's just a guess, but thats what I'd go with first.

Click to expand...

I've had a long look at the wiring diagrams and that's the only guess that I could come up with too. (Assuming that all connections are indeed 'good').