Hi chaps,
my early Mercedes benz sprinter 308d had the glow plug light staying on, which means a glow plug problem. So i have fitted new ones and now the light doesn't come on at all. Anyone out there in diy world help me out here with some advice? I have had the timer relay off and opened it up and all looks fine in there. I am suspecting there must be more glow plug controls somewhere? Does and one have a copy of the wiring diagram?
Cheers chaps
steve
Did it need new ones?
You're best arming yourself with a cheap multimeter and then you can check to see if any have gone open circuit or whether they are getting power in the first place. Replacing things before making a diagnosis can get expensive!
Anyone out there in diy world
Is it producing a 12V output for an appropriate period? Telling us it "looks fine" isn't a great deal of help.
Nope, but I've crossposted this to uk.rec.cars.maintenace where you'll stand a better chance of getting a reply from someone much better informed than me! ;-)
Tim
The Only problem I have had with GlowPlugs, was the Fuse had blown.
Baz
does it start ok? did the glow plug light come on before (in the same temps)?
I had a fusion in the other day with engine light coming on sporadically and going into limp home mode for a short time, code reading said glow plugs/circuit, every glow plug tested ok and glowed nicely when tested out of the engine, yet replacing all four has got rid of the problems. modern ecu checks the glowplugs every few minutes and if the figures differ from the presets by even a tiny amount the lights come on.
Did it need new ones?
You're best arming yourself with a cheap multimeter and then you can check to see if any have gone open circuit or whether they are getting power in the first place. Replacing things before making a diagnosis can get expensive!
Yes it did need new ones, two of them were reading very high resitance. So i replace them all as a set.
Anyone out there in diy world
Is it producing a 12V output for an appropriate period? Telling us it "looks fine" isn't a great deal of help.
No, there is no output from the relay, but there is a 12v supply to the large terminal. By 'looks fine' i mean there are no obvious signs of shorting, corrosion or dry joints etc inside it.
Nope, but I've crossposted this to uk.rec.cars.maintenace where you'll stand a better chance of getting a reply from someone much better informed than me! ;-)
Thanks for that.
Tim
Steve
The Only problem I have had with GlowPlugs, was the Fuse had blown.
Baz
I checked the fuses under the steering wheel, none are blown.
Ta
steve
does it start ok? did the glow plug light come on before (in the same temps)?
I had a fusion in the other day with engine light coming on sporadically and going into limp home mode for a short time, code reading said glow plugs/circuit, every glow plug tested ok and glowed nicely when tested out of the engine, yet replacing all four has got rid of the problems. modern ecu checks the glowplugs every few minutes and if the figures differ from the presets by even a tiny amount the lights come on.
No, it wont start. The problem first showed itself as a glow plug light that wouldn't go off once started..it stayed on all the time. Then it got harder to start and finally the glow light didn't light at all. So i replaced the glow plugs and there is still no light on the dash.
Ta
Steve
Did it need new ones?
You're best arming yourself with a cheap multimeter and then you can check to see if any have gone open circuit or whether they are getting power in the first place. Replacing things before making a diagnosis can get expensive!
Yes it did need new ones, two of them were reading very high resitance. So i replace them all as a set.
Anyone out there in diy world
Is it producing a 12V output for an appropriate period? Telling us it "looks fine" isn't a great deal of help.
No, there is no output from the relay, but there is a 12v supply to the large terminal. By 'looks fine' i mean there are no obvious signs of shorting, corrosion or dry joints etc inside it.
Nope, but I've crossposted this to uk.rec.cars.maintenace where you'll stand a better chance of getting a reply from someone much better informed than me! ;-)
Thanks for that.
Tim
Steve
I assume that the relay does not click when you first turn on the ign? if no, then it is not getting its signal to go, or the relay is faulty OR the coolant temp sender is telling it not to go because it thinks it is already warm.
If it does click in, then either the feed to it is faulty or the output does not reach the plugs.
Is it possible that you disturbed the coolant sensor when changing the plugs?
Is it possible that you disturbed the coolant sensor when changing the plugs?
Where is the coolant sensor.....:-) lol
I am not getting any click from the relay. I seem to remember that even in hot weather the glow plug light would come on as it does in the winter.
Ta
Steve
what year and what engine size is this 308d? I may be able to look at the wiring diagram and get a better idea. no idea where the coolant sensor for the glow plugs lives, sorry. I will try and work out which legs of the relay are which once I know which one to look at.
mm. unless its very cold, the glow light doesn't come on on the dash here either. But it does start.
possibly whatever it is that detects when its cold enough to need the glo plugs has failed.
what year and what engine size is this 308d? I may be able to look at the wiring diagram and get a better idea. no idea where the coolant sensor for the glow plugs lives, sorry. I will try and work out which legs of the relay are which once I know which one to look at.
I did some more multimetering, and discovered there is a switched 12v supply to the black box/relay/preheat timer delay jobbie as well as the permanently live one. I found a wiring diagram (in Dutch but heho) on the net in some deep recess, and it is looking like the temperature may be at fault, if not that then its gotta be the above black box thingy. Does anyone know what these sensors are supposed to read resistance wise? i maybe able to find a resistor to emulate a cold engine...
Cheers
Steve
what year and what engine size is this 308d? I may be able to look at the wiring diagram and get a better idea. no idea where the coolant sensor for the glow plugs lives, sorry. I will try and work out which legs of the relay are which once I know which one to look at.
Oh yeah, its a 308d 1998 i think its a 2.3 non turbo.
Cheers
steve
what year and what engine size is this 308d? I may be able to look at the wiring diagram and get a better idea. no idea where the coolant sensor for the glow plugs lives, sorry. I will try and work out which legs of the relay are which once I know which one to look at.
Oh yeah, its a 308d 1998 i think its a 2.3 non turbo.
Cheers
steve
Update. Checked the temperature sensor, it is reading 4.5Kohms and 13C here.....
Steve
the general temp range on the (dead) sensor I pulled out of pegeot GTI from the ECU was supposed to be about 3k room and 300 ohm boiling low iompedance works best on cars,,,
that sounds spot on, and if its high, it would make the thing operate, rather than t'other way around.
I wonder if you blew a fuse when fiddling?
And you found fuses for glo-plugs in there? Glo-lugs take quite a hefty current, I'd half expect the fuse(s) for them to be in an engine compartment fuse/relay box.
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