No power to my glow plugs

[Wiff74]

Can someone please advise.
The AA came out to me today as the van would not start. The result was no power to the glow plugs. The fuse is ok but has no power getting to it. Is there a relay or another switch that could be faulty? The glow plug light comes on then goes out as normal and I hear the click but no power. We directly heated the plugs and she fired up first time and after the initial fire up she starts no problem at all.

[rita]

Sounds like the Glow plug relay has a fault, it is situated behind the o/s battery. I would advise you to have it checked out by a Auto electrician/Mechanic unless you have the expertise's to do the task yourself.

[g8dhe]

The fuse or actually the fusible link is directly connected to the battery;

This then feeds the power to a relay tucked behind the battery on the far left;

this in turn feeds the glowplug busbar running the length of the engine.

[Diplomat]

... We directly heated the plugs and she fired up first time ..

Good bit of lateral thinking, there.

All that is needed is one jump lead from the battery plus to the bus bar (safest to connect to the battery last).

Would also be a quick way of diagnosing total glow plug failure if no spark occurred upon connection.


Frank

[Snail921]

Am I not right in thinking that the glowplugs are powered at less than 12v. Given that a fully charged battery is probably giving out more than 12, would this do any harm to the plugs?
regards,
Brian.

[Diplomat]

Am I not right in thinking that the glowplugs are powered at less than 12v.

On a good day the battery should be offering them well over 12v before some gets lost in the wiring and relay. However as soon as the glow plugs get to be across that voltage, even with best battery it drops. Same thing happens with the starter motor. You won't see 13.8v across the battery with these thirsty items in circuit.

Even my jumper leads with drop some volts through their croc clip teeth.

Consider also that the glow plugs come on from time to time while the engine is warming up so will be getting a bit more supply voltage with the alternator doing its bit than under cold start conditions.


Frank