Peugeot 405 preheater plugs/ glowplugs not working!

Joe390

Hey .
I have a 1993 peugeot 405 style. Lately when the engine is cold it is a pain to start. When I turn the key everything lights up except the dashlight for the preheating plugs. I tried turning the key on and off in an attempt to get the preheating plugs to work. Still no preheating light on the dash .I attempted to start the car and it wouldn't start . Then I turned off the key and turned it back on and the preheater light came on and went off after about 10 seconds and it's started right up. This happens most mornings now . Any help to shed some light on this would be grately appreciated . Thanks.

Turbulent Bill

Maybe the glowplugs are broken? I had a similar issue with an XUD9 engine (probably similar to the one in the 405), very hard to start in cold weather but warm-started every time. Turned out 3 of the 4 plugs needed to be replaced. It's more noticeable in cold weather because the plugs are more necessary.

From memory they weren't expensive to replace, maybe €25 each plus labour, but it was a while ago.

mad-for-tar

Sounds like there might be an issue with the heater plug relay or it’s wiring. It’s located in engine bay behind air filter housing next to the battery. On the heater plug side of the circuit, the power comes from a wire ran from the alternator terminal to this box and feeds out to the glow plugs themselves. Should be another connector which has about 5 wires in it, one is a feed from ignition switch, a ground, a supply to the dash warning lamp, a supply in which comes from the cranking terminal on starter motor and a feed out to the post heating relay if it has one.
Might need to inspect these connections at the relay itself and see if there is anything loose or corroded.
To test the heater plugs the,selves, easiest way if you can get easy access is to remove the connection strip from the 4 plugs, take a length of wire from the battery positive terminal and strike the other end of it on the threaded tip of each plug in turn. If you get some small sparks, the plug is ok but if you get nothing, the plug is dead.
Had an STDT model myself about 15years ago which I got to know every nut and bolt on it, info I have is from vague memory and an old Haynes Peugeot Diesel engine manual I have still. Hope it helps.

Joe390

Turbulent Bill wrote: »

Maybe the glowplugs are broken? I had a similar issue with an XUD9 engine (probably similar to the one in the 405), very hard to start in cold weather but warm-started every time. Turned out 3 of the 4 plugs needed to be replaced. It's more noticeable in cold weather because the plugs are more necessary.

From memory they weren't expensive to replace, maybe €25 each plus labour, but it was a while ago.

Hi turbulent bill, thanks for your reply. I was wonder

Joe390

Turbulent Bill wrote: »

Maybe the glowplugs are broken? I had a similar issue with an XUD9 engine (probably similar to the one in the 405), very hard to start in cold weather but warm-started every time. Turned out 3 of the 4 plugs needed to be replaced. It's more noticeable in cold weather because the plugs are more necessary.

From memory they weren't expensive to replace, maybe €25 each plus labour, but it was a while ago.

Hi turbulent bill, thanks for your reply. I was wondering would the car still start if the glowplugs were broken. I will try and test the glowplugs as soon as I can . Thanks again

Joe390

mad-for-tar wrote: »

Sounds like there might be an issue with the heater plug relay or it’s wiring. It’s located in engine bay behind air filter housing next to the battery. On the heater plug side of the circuit, the power comes from a wire ran from the alternator terminal to this box and feeds out to the glow plugs themselves. Should be another connector which has about 5 wires in it, one is a feed from ignition switch, a ground, a supply to the dash warning lamp, a supply in which comes from the cranking terminal on starter motor and a feed out to the post heating relay if it has one.
Might need to inspect these connections at the relay itself and see if there is anything loose or corroded.
To test the heater plugs the,selves, easiest way if you can get easy access is to remove the connection strip from the 4 plugs, take a length of wire from the battery positive terminal and strike the other end of it on the threaded tip of each plug in turn. If you get some small sparks, the plug is ok but if you get nothing, the plug is dead.
Had an STDT model myself about 15years ago which I got to know every nut and bolt on it, info I have is from vague memory and an old Haynes Peugeot Diesel engine manual I have still. Hope it helps.

Thanks for your reply, mad for tar, what does the relay look like . Is there a heaterplug relay or a control module for the peugeot 405 . This is just out of interest but what is the difference between the two. I will try to locate the relay and clean the connections . Thanks again😊

Turbulent Bill

Joe390 wrote: »

Hi turbulent bill, thanks for your reply. I was wondering would the car still start if the glowplugs were broken. I will try and test the glowplugs as soon as I can . Thanks again

My understanding is that the car would start with some of the glowplugs broken, provided that the temperature wasn't too low. That's why mine wasn't an issue during the summer, or for warm starting. At least some preheating is enough to get things moving.

The other suggestion of a wiring or connection issue is valid too, given that it seems to be intermittent.

Joe390

Thanks to ye for helping with this problem . I found the relay beside the battery and I took it off and looked underneath . 1 of the red wires was slightly corroded so I sprayed some wd40 on it and it seems to have fixed the problem. The plug which has only 4 wires on my car was completely clean so that wasn't the problem. I then put it back together and when i tried to start it The preheater plug light came straight on on the dash and I stopped it and started it a few times while letting it preheat . It seems to be working as normal now again . THANKS AND HAPPY NEW YEAR!!!

mad-for-tar

Joe390 wrote: »

Thanks for your reply, mad for tar, what does the relay look like . Is there a heaterplug relay or a control module for the peugeot 405 . This is just out of interest but what is the difference between the two. I will try to locate the relay and clean the connections . Thanks again��

Looks like the pics at these links:
https://www.proxyparts.com/upload/parts/100278/1767146/large/0.jpg
http://img.auctiva.com/imgdata/1/1/1/6/1/5/7/webimg/477057096_o.jpg

This is your main heater plug relay control module and the one responsible for activating the glow plugs at key on.

The other relay I mention, the post heating one, I'm not sure of its location, however, I don't think this part of the circuit is causing you any issues. The post heating circuit allows selective control of switching the glow plugs on and off whilst engine is running until it gets up to a certain temperature determined by a temperature switch on the engine.

In any case, concentrate on the pre heating circuit controlled by this large relay next to the battery and airbox as per the links above. Circuit is not very complex by any means, relay itself could well be faulty.

mad-for-tar

Joe390 wrote: »

Thanks to ye for helping with this problem . I found the relay beside the battery and I took it off and looked underneath . 1 of the red wires was slightly corroded so I sprayed some wd40 on it and it seems to have fixed the problem. The plug which has only 4 wires on my car was completely clean so that wasn't the problem. I then put it back together and when i tried to start it The preheater plug light came straight on on the dash and I stopped it and started it a few times while letting it preheat . It seems to be working as normal now again . THANKS AND HAPPY NEW YEAR!!!

Good man, fair play. Just make sure those connections are tight in any case. If it acts up again, keep fiddling around there and you might find the root cause. But for now enjoy the easy starts. Happy New Year also!.

Joe390

Hey , just thought I'd keep ye up to date on the peugeot and If anyone else had these problems they might find this thread. After awhile of the glowplugs working as they should, they just completly stopped working. I bought a control box (that is beside the battery) from a scrappers connected it up and it has worked without fault since. Thanks again for helping