Re: [MBZ] Testing glow plugs
Max wrote: '95 E300: all measured between 0.7 and 0.9 ohms, at the six-pin connector for the glow plug relay. What I've found to be the best way to test glow plugs is to measure the current draw. I think I will build a current tester next, using a cheap dash-mount amp meter from FLAPS. Heh. Seems you've heard me expound on that method before. *grin* That should prove your plugs are good. If you are still getting errors, then maybe the error checker is at fault. ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing glow plugs
Shell out for a new (or used) GP Relay. 95 E300: all measured between 0.7 and 0.9 ohms, at the six-pin connector for the glow plug relay. However, the pre-glow light is telling me there is a problem. Roughly half the time it won't light during the pre-glow cycle and then comes on immediately after engine start, or it does light as normal but then after a minute of operation it will come one for a bit. Engine start is smooth, so the majority if not all of the plugs are working. I think I will build a current tester next, using a cheap dash-mount amp meter from FLAPS. -- Max Dillon Charleston SC '87 300TD '95 E300 ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing Glow Plugs
I was thinking that was the total amperage draw on 5 GPs, in which case the resistance would be 5x higher on each plug. --R On 12/2/13 6:50 PM, Fmiser wrote: Rich Thomas wrote: They should show just a few ohms of resistance, like 3 or 4 if I recall. Zero not good, infinite not good. Mitch Haley wrote: Don't they draw 20-30 amps when cold? That would imply about half an ohm. Rich Thomas wrote: Divide by 5 Divide what by 5? The 0.5 ohm each? To figure the total resistance of all the plugs (presuming parallel glowplugs) is 1/((1/0.6)*5) --Philip ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing Glow Plugs
Room temperature resistance should be 0.7 to 0.8 ohm. It will go up quite a bit as they heat, of course. Peter ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing Glow Plugs
I was thinking that was the total amperage draw on 5 GPs, in which case the resistance would be 5x higher on each plug. No, the initial amperage is quite high. If the fuse were instant reacting it'd probably blow every time. -- Jim ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing Glow Plugs
Hi Gang, I tried to test the GP using my 12v battery with the GP removed since i had already pulled it - it didn't even get warm -- i then tested it as many ways that i could think of using my DMM - zero continuity, (I tested between the threads and the probe as well as the threaded connector) i aso tested for Resistance and got max numbers in a place where I wanted as close to zero as possible - so naturally the numbers were greater than 50.0 so I'm pretty sure that's a dead GP. There's a opening somewhere between the threaded connector and the probe. I am assuming the GP is like a light bulb -- IOW -- it should have a short that makes the probe get hot? Still have 3 more to test Anyone ready to step up to Amsoil? ;-) I'm here to help - Larry Please Visit My AMSOIL Online Store: http://www.amsoil.com/StoreFront/default.aspx?zo=5114156 Oil Analysis Site - www.youroil.net On 11/23/2013 7:00 PM, Fmiser wrote: Larry wrote: I was wondering - I'd like to test the GPs on my 240D - would it be acceptable to hook them 1 at a time to my battery charger? I read the archives about testing GPs and the point was made that a GP might test good with a meter when cold - but can fail when it heats up - if I use my Battery charger won't I cover that hot/cold problem? Yes - but all you will be able to tell is if it glows. I think it's a lot easier to test it still in the engine. I attached 12 AWG wire leads to an old automotive dash style ammeter that reads -30 0 +30 Amps. To use it, I pop the top off of the glow relay and unplug the connector for the glow plugs. There is a contact for each glow plug in this connector. I clip one meter lead to the fused side of the big, screw-in fuse and then touch each glowplug contact, one at a time. The socket has pin numbers molded into it, and these numbers correspond to the cylinder number. This method tests the supply 12V, the wire, and the plug. When cold, a good plug draws about 20A (Well, on my meter it point to the mark for 20 amps. I have not calibrated or tested the accuracy of that meter...) It will drop back to about 15A after 8-10 seconds. Once the one wire is connected to the fuse, DO NOT LET THE OTHER WIRE TOUCH CHASSIS GROUND!!! Or the big fuse will blow and possibly so will your ammeter. :) If the plug is bad, the current will usually be less. If it is shorted it will be much more. If the wire or connectors are in poor shape, the current will be less. If the supply voltage is low, the current will be less. -- Philip ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing Glow Plugs
If they represent an open circuit, they work as well as a blown light bulb. Mitch. ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing Glow Plugs
They should show just a few ohms of resistance, like 3 or 4 if I recall. Zero not good, infinite not good. --R On 12/2/13 12:15 PM, Larry T wrote: Hi Gang, I tried to test the GP using my 12v battery with the GP removed since i had already pulled it - it didn't even get warm -- i then tested it as many ways that i could think of using my DMM - zero continuity, (I tested between the threads and the probe as well as the threaded connector) i aso tested for Resistance and got max numbers in a place where I wanted as close to zero as possible - so naturally the numbers were greater than 50.0 so I'm pretty sure that's a dead GP. There's a opening somewhere between the threaded connector and the probe. I am assuming the GP is like a light bulb -- IOW -- it should have a short that makes the probe get hot? Still have 3 more to test Anyone ready to step up to Amsoil? ;-) I'm here to help - Larry Please Visit My AMSOIL Online Store: http://www.amsoil.com/StoreFront/default.aspx?zo=5114156 Oil Analysis Site - www.youroil.net On 11/23/2013 7:00 PM, Fmiser wrote: Larry wrote: I was wondering - I'd like to test the GPs on my 240D - would it be acceptable to hook them 1 at a time to my battery charger? I read the archives about testing GPs and the point was made that a GP might test good with a meter when cold - but can fail when it heats up - if I use my Battery charger won't I cover that hot/cold problem? Yes - but all you will be able to tell is if it glows. I think it's a lot easier to test it still in the engine. I attached 12 AWG wire leads to an old automotive dash style ammeter that reads -30 0 +30 Amps. To use it, I pop the top off of the glow relay and unplug the connector for the glow plugs. There is a contact for each glow plug in this connector. I clip one meter lead to the fused side of the big, screw-in fuse and then touch each glowplug contact, one at a time. The socket has pin numbers molded into it, and these numbers correspond to the cylinder number. This method tests the supply 12V, the wire, and the plug. When cold, a good plug draws about 20A (Well, on my meter it point to the mark for 20 amps. I have not calibrated or tested the accuracy of that meter...) It will drop back to about 15A after 8-10 seconds. Once the one wire is connected to the fuse, DO NOT LET THE OTHER WIRE TOUCH CHASSIS GROUND!!! Or the big fuse will blow and possibly so will your ammeter. :) If the plug is bad, the current will usually be less. If it is shorted it will be much more. If the wire or connectors are in poor shape, the current will be less. If the supply voltage is low, the current will be less. -- Philip ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing Glow Plugs
Rich Thomas wrote: They should show just a few ohms of resistance, like 3 or 4 if I recall. Zero not good, infinite not good. Don't they draw 20-30 amps when cold? That would imply about half an ohm. Mitch. ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing Glow Plugs
Divide by 5 --R On 12/2/13 2:09 PM, Mitch Haley wrote: Rich Thomas wrote: They should show just a few ohms of resistance, like 3 or 4 if I recall. Zero not good, infinite not good. Don't they draw 20-30 amps when cold? That would imply about half an ohm. Mitch. ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing Glow Plugs
I thought that a single plug started out over 20 and quickly dropped as it heated. Paging Mr Cathey... Mitch. Rich Thomas wrote: Divide by 5 --R On 12/2/13 2:09 PM, Mitch Haley wrote: Rich Thomas wrote: They should show just a few ohms of resistance, like 3 or 4 if I recall. Zero not good, infinite not good. Don't they draw 20-30 amps when cold? That would imply about half an ohm. Mitch. ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing Glow Plugs
On Mon, 02 Dec 2013 18:33:48 -0500 Mitch Haley m...@voyager.net wrote: I thought that a single plug started out over 20 and quickly dropped as it heated. Paging Mr Cathey... I'm not Cathy, but yes, the plugs do draw on the order of 15-20A each when they are cold. Craig ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing Glow Plugs
Rich Thomas wrote: They should show just a few ohms of resistance, like 3 or 4 if I recall. Zero not good, infinite not good. Mitch Haley wrote: Don't they draw 20-30 amps when cold? That would imply about half an ohm. Rich Thomas wrote: Divide by 5 Divide what by 5? The 0.5 ohm each? To figure the total resistance of all the plugs (presuming parallel glowplugs) is 1/((1/0.6)*5) --Philip ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing Glow Plugs
I thought that a single plug started out over 20 and quickly dropped as it heated. Something like that. Cold, the GP's are about 0.7 ohms. -- Jim ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing Glow Plugs
Thanks for the suggestion -- I'm not sire it will work on my 300D with the GPR under the dash. //But I'll read your commment and see if I can apply them to my 240D, Will save the directions for my 300D although i have done the WSM tests on it successfully. Never hurts to have alternatives Sorry about the odd formating -- (if it is coming through on your end.) BTW, If anyone is interested in learning about Amsoil let me know :-) *Larry Please Visit My AMSOIL Online Store: http://www.amsoil.com/StoreFront/default.aspx?zo=5114156 Oil Analysis Site - www.youroil.net* On 11/23/2013 7:00 PM, Fmiser wrote: Larry wrote: I was wondering - I'd like to test the GPs on my 240D - would it be acceptable to hook them 1 at a time to my battery charger? I read the archives about testing GPs and the point was made that a GP might test good with a meter when cold - but can fail when it heats up - if I use my Battery charger won't I cover that hot/cold problem? Yes - but all you will be able to tell is if it glows. I think it's a lot easier to test it still in the engine. I attached 12 AWG wire leads to an old automotive dash style ammeter that reads -30 0 +30 Amps. To use it, I pop the top off of the glow relay and unplug the connector for the glow plugs. There is a contact for each glow plug in this connector. I clip one meter lead to the fused side of the big, screw-in fuse and then touch each glowplug contact, one at a time. The socket has pin numbers molded into it, and these numbers correspond to the cylinder number. This method tests the supply 12V, the wire, and the plug. When cold, a good plug draws about 20A (Well, on my meter it point to the mark for 20 amps. I have not calibrated or tested the accuracy of that meter...) It will drop back to about 15A after 8-10 seconds. Once the one wire is connected to the fuse, DO NOT LET THE OTHER WIRE TOUCH CHASSIS GROUND!!! Or the big fuse will blow and possibly so will your ammeter. :) If the plug is bad, the current will usually be less. If it is shorted it will be much more. If the wire or connectors are in poor shape, the current will be less. If the supply voltage is low, the current will be less. -- Philip ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing Glow Plugs
On Sat, 23 Nov 2013 12:16:48 -0500 Larry T l02tur...@comcast.net wrote: I was wondering - I'd like to test the GPs on my 240D - would it be acceptable to hook them 1 at a time to my battery charger? I read the archives about testing GPs and the point was made that a GP might test good with a meter when cold - but can fail when it heats up - if I use my Battery charger won't I cover that hot/cold problem? Your battery charger won't put out enough current to operate the glow plug. - Remove the glow plug (of course) - Clamp the hex with a pair of vise-grips - Touch the glow plug's center terminal to one battery terminal - Touch the handle end of the vise-grips to the other battery terminal, if it's not long enough, extend with a wrench or something conductive - Watch for the orange glow from the glow plug CAUTION: The glow plug will be REALLY hot! To test another, release the vise-grips to drop the tested glow plug onto your concrete garage floor or something equally non-damagable. Craig ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing Glow Plugs
I test all of the old ones I pull from the car with this method. I also test the new ones before putting them in the car. Last time I did this, 3 of the 5 still glowed, just as brightly as the new ones. Michael E. Esh 231-286-2344 On Nov 23, 2013, at 12:16 PM, Larry T l02tur...@comcast.net wrote: I was wondering - I'd like to test the GPs on my 240D - would it be acceptable to hook them 1 at a time to my battery charger? I read the archives about testing GPs and the point was made that a GP might test good with a meter when cold - but can fail when it heats up - if I use my Battery charger won't I cover that hot/cold problem? Thanks -- Larry Please Visit My AMSOIL Online Store: http://www.amsoil.com/StoreFront/default.aspx?zo=5114156 Oil Analysis Site - www.youroil.net ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing Glow Plugs
Thanks Craig! Sounds good. I really appreciate your help - Larry Please Visit My AMSOIL Online Store: http://www.amsoil.com/StoreFront/default.aspx?zo=5114156 Oil Analysis Site - www.youroil.net On 11/23/2013 3:01 PM, Craig wrote: On Sat, 23 Nov 2013 12:16:48 -0500 Larry T l02tur...@comcast.net wrote: I was wondering - I'd like to test the GPs on my 240D - would it be acceptable to hook them 1 at a time to my battery charger? I read the archives about testing GPs and the point was made that a GP might test good with a meter when cold - but can fail when it heats up - if I use my Battery charger won't I cover that hot/cold problem? Your battery charger won't put out enough current to operate the glow plug. - Remove the glow plug (of course) - Clamp the hex with a pair of vise-grips - Touch the glow plug's center terminal to one battery terminal - Touch the handle end of the vise-grips to the other battery terminal, if it's not long enough, extend with a wrench or something conductive - Watch for the orange glow from the glow plug CAUTION: The glow plug will be REALLY hot! To test another, release the vise-grips to drop the tested glow plug onto your concrete garage floor or something equally non-damagable. Craig ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Testing Glow Plugs
Larry wrote: I was wondering - I'd like to test the GPs on my 240D - would it be acceptable to hook them 1 at a time to my battery charger? I read the archives about testing GPs and the point was made that a GP might test good with a meter when cold - but can fail when it heats up - if I use my Battery charger won't I cover that hot/cold problem? Yes - but all you will be able to tell is if it glows. I think it's a lot easier to test it still in the engine. I attached 12 AWG wire leads to an old automotive dash style ammeter that reads -30 0 +30 Amps. To use it, I pop the top off of the glow relay and unplug the connector for the glow plugs. There is a contact for each glow plug in this connector. I clip one meter lead to the fused side of the big, screw-in fuse and then touch each glowplug contact, one at a time. The socket has pin numbers molded into it, and these numbers correspond to the cylinder number. This method tests the supply 12V, the wire, and the plug. When cold, a good plug draws about 20A (Well, on my meter it point to the mark for 20 amps. I have not calibrated or tested the accuracy of that meter...) It will drop back to about 15A after 8-10 seconds. Once the one wire is connected to the fuse, DO NOT LET THE OTHER WIRE TOUCH CHASSIS GROUND!!! Or the big fuse will blow and possibly so will your ammeter. :) If the plug is bad, the current will usually be less. If it is shorted it will be much more. If the wire or connectors are in poor shape, the current will be less. If the supply voltage is low, the current will be less. -- Philip ___ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
