Volvo MD2020 No Power To Glowplugs

[Jokani]

On the last couple of times starting the engine, when I switch on the the glow plugs and start counting to 30, the power to them has switched off after approx 15 seconds, but this has been enough to get her started.

This weekend no power to the plugs at all.

I have started to try and find the problem, I have power in an out of the fuse box and there is power to the control panel. When switched on, the glow plowplug light does light up, but ther isn’t any power coming out of the loom wire that connects to the glow plug bar.

Any ideas where the fault lies or what I should test next.

TIA

 

[tillergirl]

Change the relay.

On my 2030 I need no more than 3 or 4 seconds!

 

[VicS]

On the last couple of times starting the engine, when I switch on the the glow plugs and start counting to 30, the power to them has switched off after approx 15 seconds, but this has been enough to get her started.

This weekend no power to the plugs at all.

I have started to try and find the problem, I have power in an out of the fuse box and there is power to the control panel. When switched on, the glow plowplug light does light up, but ther isn’t any power coming out of the loom wire that connects to the glow plug bar.

Any ideas where the fault lies or what I should test next.

TIA

Refer to the wiring diagram in the manual to identify the wiring colours.

Check the operation of the glowplug relay. Change it if it proves to be faulty.

The exact behavior of the glowplug warning light depends on the version. In most cases it indicates that power is getting to the relay coil, in others that power is getting through the switched contacts and should be reaching the glowplugs.

Use a test lamp ( 12 volt bulb on a couple of leads) to check for power. Not a digital voltmeter. They take so little current that they will often give a normal reading through a poor connection. Sooner or later that ill make a fool of you.

 

[tillergirl]

As a PS, perhaps all the glow plugs have now failed. I didn't realise that two had already failed over the 20 old years until the third one failed!

 

[Jokani]

Ta for all the replies. Sounds like it is the relay, I’ll see if I can find that and take it from there.

 

[VicS]

Ta for all the replies. Sounds like it is the relay, I’ll see if I can find that and take it from there.

Its in the relay box .

ITYWF it's the same as the starter relay so can be checked by swapping them.

 

[duncan99210]

The relays fit into sockets but the connectors are essentially female spade connectors (the same as you crimp on to a wire). Over time they can work loose, so you can use a fine bladed screwdriver to bend the connectors slightly to tighten them up. Had to do this for both the starter and glow relays in the past.

 

[oldharry]

Start wityh checking the realy as above. If thats not it, check the glow plugs themselves. One gone makes very little difference, two gone makes sluggish starting, three gone almost impossible. If the engine has been more and more sluggish starting, this could be the cause. They usually fail open circuit so a dvm will tell you whether there's continuity after the wire is disconnected, but they need to be pulled and checked to see if they heat up to an even red glow to finally prove them.

 

[VicS]

Start wityh checking the realy as above. If thats not it, check the glow plugs themselves. One gone makes very little difference, two gone makes sluggish starting, three gone almost impossible. If the engine has been more and more sluggish starting, this could be the cause. They usually fail open circuit so a dvm will tell you whether there's continuity after the wire is disconnected, but they need to be pulled and checked to see if they heat up to an even red glow to finally prove them.

The OP says there is no power to the glowplugs

 

[oldharry]

The OP says there is no power to the glowplugs

Yes but if there is a timer (light switches off after 15 seconds) it may be sensing an overload due to a shorted plug, and cutting off straight away. In any case as others say, it should only require a few seconds glow plugs for the engine to catch which points to a glowplug fault? Sluggish starting then failed starting...?

 

[chrishelen]

Yes but if there is a timer (light switches off after 15 seconds) it may be sensing an overload due to a shorted plug, and cutting off straight away. In any case as others say, it should only require a few seconds glow plugs for the engine to catch which points to a glowplug fault? Sluggish starting then failed starting...?

My perkins perama (volvo 2030) needs no more than 7 seconds heat on the coldest of days. Perhaps the plugs are timing out.

 

[VicS]

Yes but if there is a timer (light switches off after 15 seconds) it may be sensing an overload due to a shorted plug, and cutting off straight away. In any case as others say, it should only require a few seconds glow plugs for the engine to catch which points to a glowplug fault? Sluggish starting then failed starting...?

I dont think you will find that the system is anything like that clever. The Glowplugs are energised by holding the key in the "heat" position or holding down the "heat" button for 10secs (max 30 secs). Although the oldest manual I have says 20 to 30 secs ( max 60 secs)

The light merely indicates that the glowplugs are being energised manually although there is some variation as to exactly where the warning light is connected. There is no suggestion that there is any timer, other than the operator. The relay is a simple relay not incorporating any timing. Both relays in the box, the glowplug relay and the starter relay, have the same part number.

 

[TSB240]

The relay is a simple relay not incorporating any timing. Both relays in the box, the glowplug relay and the starter relay, have the same part number.

This is indeed a very common problem on all of the MD20x0 range of engines. Volvo in their wisdom put the Black Plastic box with the start and glow plug relay and fuse mounted to the side of the engine hung on a flimsy tuning fork. Before you start looking at replacing any Glowplugs unscrew the lid, Wiggle both relays back in their sockets and try starting. If the relay and glowplug is working the heater light dims. I have packed ours out with a piece of card that jams the relays into the sockets when the lid is replaced. Not had a problem since.

Post No7 is probably a good long term solution!

 

[Jokani]

Its in the relay box .

ITYWF it's the same as the starter relay so can be checked by swapping them.

Thanks for this info, I did find both the relays, helpfully someone has marked them bit "S" and "G" in white pen. I removed the glowplug one, two of the pins look as though they have got hot or corroded.

I didn't fancy swapping the starter one, if I broke it, I'd have struggled to make it back to the marina. A handy tip to know for the future though.

Struggled to start this morning, I wired the glowplug bar to the pos bus bar for 10 seconds, and it fired within a turn.

Unfortuantely I am now not at the boat for 2 weeks, but will return with a new relay and a spare, feeling confident that will sort the problem.

Thanks again.

 

[Jokani]

The relays fit into sockets but the connectors are essentially female spade connectors (the same as you crimp on to a wire). Over time they can work loose, so you can use a fine bladed screwdriver to bend the connectors slightly to tighten them up.

Damn only just seen this and not on the boat now, but I'll try this to see if I can get it to work before I fit a new one. Ta.

 

[Jokani]

Before you start looking at replacing any Glowplugs unscrew the lid, Wiggle both relays back in their sockets and try starting. If the relay and glowplug is working the heater light dims. I have packed ours out with a piece of card that jams the relays into the sockets when the lid is replaced. Not had a problem since.

Thanks, I have made a note about the light dimming, that's helpful, ta.

 

[Jokani]

A quick update, I bought a cheap no brand relay from Ebay, didn't work, but did some strange things, such us the fuel gauge went down by half when the glowplugs were switched on. I then bit the bullet and bought a VP relay from Volspec, now all works a treat.

Thanks for all the advice, once again, much appreciated!