glow plug light broken? - Printable Version +- STD (https://www.superturbodiesel.com/std) +-- Forum: Maintenance (https://www.superturbodiesel.com/std/forumdisplay.php?fid=22) +--- Forum: General (https://www.superturbodiesel.com/std/forumdisplay.php?fid=4) +--- Thread: glow plug light broken? (/showthread.php?tid=2805)

glow plug light broken? - larsalan - 07-20-2011 For some reason the glow plug light on the dash won't light up. Car starts/runs fine though. What could be wrong? I looked at the fuse in the relay box and it's intact. RE: glow plug light broken? - Biohazard - 07-20-2011 I would guess dead bulb. Not too terrible to get too. I haven't looked at one in a while, but it may be a 194 bulb. RE: glow plug light broken? - dieselboy - 07-20-2011 I had mine fall out of the bulb socket once. RE: glow plug light broken? - larsalan - 07-27-2011 I believe the problem is in the ignition switch. I mean the part the key goes into. I have been able to get the light to come on sometimes if I turn the key very very slowly. How can I fix this? Winter is on the way. And how do the plugs even work? Are they just hot for when the motor starts and then they stay off? RE: glow plug light broken? - Hercules - 07-27-2011 Possible burned out glow plug. Glow timer is( partly ) auto.test of system. If one or more glow plugs burned out,Light can stay out,flash,or stay on after starting. One bad glow plug usually goes undetected by driver. RE: glow plug light broken? - larsalan - 07-27-2011 Not a problem with the ignition switch? Should I unhook all the plugs from each other and check each for continuity? I don't have a voltmeter but I could rig a speaker to test for any continuity. Why do you write like 'car.mercedes.motor'? Is that some .net programming stuff. You're wierding me out RE: glow plug light broken? - Hercules - 07-28-2011 Don't mean to weird you out but when you have owned your own Mbz shop for 30 years you tend to know and go straight to the problem. Had a lot of strange things happen in that amount of time. Possible ignition switch, but not likely. Never seen it in 30 years, but is possible. Testing glow system, voltmeter very inaccurate. Disconnect glow wires at timer box, use insulated jumper wire, connect to each glow plug one at a time and touch battery positive briefly, if sparks glow plug usually good. Use caution, Good luck!! RE: glow plug light broken? - larsalan - 07-29-2011 So, straight 12v from a battery. + to the end and - to the threads that hit the block, right? First one I checked was no spark and no glow. They are 12v right not stepped up in that relay box. Also, what's that wire that goes from the plugs to the intake manifold? A sensor for intake temp I guess. Oh, also is it ok to use that anti-seeze? I mean it has copper all in it so it should be conductive, right? RE: glow plug light broken? - winmutt - 07-29-2011 Uh. Just measure resistance on the glow plugs at the relay. Dieselgiant.com has a DIY. The car tests the circuit the same way. None of these tests are actually perfect, as the reistance can be OK and it can still be failed. The only real test is to pull them and power them up, but for your issues resistance is good enough. RE: glow plug light broken? - larsalan - 07-29-2011 That's what I was saying. I pulled one out and 'powered it up' by connecting it to the battery. No spark, no glow. Something like this, But I used 12ga romex and I don't have a voltmeter. This repair will have to wait a minute since no stores have the plugs and I have to move on moday. So I guess there will be a bit of cranking till amazon sends me some boschs. How about that anti seeze. Is that ok? RE: glow plug light broken? - DeliveryValve - 07-29-2011 Another trick is to unhook the glow plug wire loom at the relay box as Herc suggested, but instead of sparking the connector, I like to use a cheap voltage light tester on each lead on the connector. More times then not, you can determine which plug is burnt out. . RE: glow plug light broken? - larsalan - 07-29-2011 I guess at least the #5 is burned out if it won't glow directly on a battery. Probably a few more too since now I am having trouble starting in the 'cold' mornings. RE: glow plug light broken? - Hercules - 07-29-2011 Anti-seize on glow plug threads (I do) keeps glow plug from seizing in. Current draw (20 amps + - close to being same). Most of us make due with the testing equipment we have. Most of us can get an insulated piece of wire with an alligator clip on one end and bare wire on the other end. After disconnecting glow plug timer plug in to glow plugs, connect alligator clip directly on electrical wire connector or glow plug nut. (if connecting on glow plug threads if it arches you can have a hard time getting nut off). One at a time drag bare wire across positive post of battery, watch for sparking. No current draw=No spark=NO good. Current draw test (amps) most accurate way of testing. Has Never failed. Can not be guessing when working on someone else's car. This test should take about 3 minutes to test all the glow plugs. Why would you want to take them out to test?? Unless you already have them out. Note: do not interchange earlier version of glow plug with later version. Different voltage. 11v compared to 12v. Later version is neck down at very end. Must be complete set, meaning all 11v or all 12v, no mix and match. That's if you want glow plug light to work properly. Also suggest 11v for easier cold starting, that's why they were designed. HIGHLY SUGGEST Bosch. Breu probable ok. Leave ALL others alone. As noted, #5 hardest to get out, is the one that burns out the most. LOL One burned out glow plug, usually not noticed. Two plugs burned out, a little hard to start. Three plugs burned out HARD to start. Four plugs, you ain't getting this baby started. Five plugs burned out, order a new glow plug timer and new glow plugs, and get a ride to the movies. Maximum glow time is 90 seconds, make sure it shuts off. RE: glow plug light broken? - larsalan - 07-29-2011 Good info, I will get back to you on what happens. I ordered 2 bosch plugs from amazon at 12.77ea. I am really strapped for $ and would rather have $25 worth of #2 but, she needs plugs I guess. I have concluded that #5 is busted and likely another 1 or 2 as you say.