Jump to content

Glow plugs not working, where to start?


Recommended Posts

If it is the same as on the 19J (2.5TD) and I'm sure it is, then there is no fuse or relay, it is a very simple arrangement. The feed from the positive terminal on the starter motor goes to the ignition switch via a thick brown wire then out to the glow plugs via an equally thick brown wire with a red trace. I think there will be a smaller brown/red wire coming from this to light up the dash light. I would guess either the bulb in the dash is dead or the ingnition switch is dead.

You'll need to get to the ignition switch to look at the wires. Check you've got 12v on the brown wire from the starter motor terminal. Then check for 12V on the thick red/brown wire while turning the switch to the cold start position. I would imagine you won't have 12v there. If so, I think the ignition switch will be dead.

Be very careful not to earth the feed any of these wires on this circuit. I didn't notice one of the glowplug terminals was ever so slightly touching the head. It resulted in the main feed melting because there isn't a fuse to blow!

Link to comment
Share on other sites

no relay or fuse on pre tdi diesel engine glowplugs,

 

they take a direct feed from battery +ve to ignition switch & should energise with the dash light on as you hold the key to the heater plug position before going into the spring loaded part of ign switch.

Link to comment
Share on other sites

Thanks for the replies, was working as described by you, Western until I brought it across France, now neither the glowplugs or the light are working so it does sound like an ignition switch issue. Annoyingly I have no voltmeter with me to test it but would it be safe to remove the wires from the switch and short them just briefly to test there is current?

Link to comment
Share on other sites

Not a recommended procedure, have you not got a spare bulb you could test it with.

I would check to see if there is power coming to the first plug at the back of the engine first, then check where the  brown/red wire comes off the ign. switch.

If no power there then new switch.

Link to comment
Share on other sites

I agree with the post above^^^. I don't think it's a good idea to short the wires while they are live. I guess it would be an okay idea providing you disconnect the positive terminial of the battery before bypassing the ignition switch, then just quickly put the positive lead back on the battery while someone confirms that the warning lamp lights up, as soon as it does, disonnect the battery again and put the wires back on the switch so you know where they go when you do replace the switch.

Failing that I think given the simplicity of the circuit, I think the most likely problem is going to be the ignition switch and they are quite cheap, so it might be worth just getting the switch swapped and seeing if that fixes the problem. I think it will.

Link to comment
Share on other sites

OK thanks for the advice guys. Just had an investigative look and gained access to the ignition switch. As I know next to nothing about electrics I think your idea is best monkey. I may try and get hold of a voltmeter in the first instance though as it seems like a useful thing to have for next time something goes wrong. Plus getting any parts shipped to where I now live in france is bloody costly. 

Link to comment
Share on other sites

just buy it online, I looked quickly on amazon.fr and found this

https://www.amazon.fr/Etekcity®-Multimètre-Rétroéclairé-Résistance-Continuité/dp/B00S7J7L7Q/ref=sr_1_1?ie=UTF8&qid=1477495008&sr=8-1&keywords=multimetre+voltmetre

I am sure the bay of many things also has them for cheaper

I have been using a el-cheapo like that for years, works fine and have no qualms about throwing it into my toolbox.

 

Link to comment
Share on other sites

Here's the switch and they ship to France. - Maybe get 2 switches just incase!

http://www.paddockspares.com/prc2735-starter-switch-diesel-2-5na-2-5td.html

The switch is held into the metal housing by one (or two) extremely small screws and of course they are in the most awkward place to access. I'm sure you will get your money's worth from a voltmeter on your 110.

Link to comment
Share on other sites

Can't offer advice on fixing the problem, and appreciate you would like them sorted......But am i right in thinking that glow plugs are ineffective unless the temperature drops below -20° or something!?! So starting shouldn't be an issue, unless it's already -20° where you are???

Link to comment
Share on other sites

52 minutes ago, Mutley said:

Can't offer advice on fixing the problem, and appreciate you would like them sorted......But am i right in thinking that glow plugs are ineffective unless the temperature drops below -20° or something!?! So starting shouldn't be an issue, unless it's already -20° where you are???

Not on old diesels, especially the pre-Tdi ones with indirect injection. In my experience they simply won't start easily with out a good 10-15 seconds of heat.

Link to comment
Share on other sites

Monkie, you could well be right as i have no idea, but think i read it somewhere in a thread on here some years ago???

Mine is a 300Tdi  '95 and for a long time the glow plugs were not connected, and started trouble free upto -10°

Thought all diesels started the same way so age would be irrelevant with regards for the need of glow plugs in extreme cold conditions? But always willing to be educated, as sometimes memory lets me down, yes i know it's an age thing.

Link to comment
Share on other sites

Hi all, thanks for all the input. Still waiting on ignition switch to arrive annoyingly- thanks for your kind offer mo murphy, annoyingly I had already ordered from paddock by the time i saw your post. 

I have very little chance of starting her without preheating the glowplugs it takes a dozen or so turns which is normally enough to put the battery in trouble. With glow plugs it starts instantly. Hopefully the part arrives soon as I it's only getting colder here. 

Link to comment
Share on other sites

OK- problem not solved. New switch in place but no dice. Switch is working fine- but the lead for the lights in the position of the glow plug start and lights work. Glow plugs and respective wiring tested by attaching to first ignition position and all fine. Have had to put the battery on charge now pissing around for a few hours has drained it . Maybe a full battery is the answer... I have my doubts. So any ideas anyone? Tempting to wire in a high tolerance simple on off switch on a separate circuit and carry on as everything else is working. Voltmeter has just arrived as well but can't see that being helpful now as both switch and wiring is fine. I am confused. Many swear words. 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy