With cold engine during summer months probably 20-30 seconds or so. One of the small wires on the GPR is 12V with key on. The other small wire goes to the PCM and is grounded by the PCM to activate the relay during glow plug on time. To start disconnect one of the small wires PPL/ORG and the GPR should not energize and that large wire should FORD FOCUS C MAX Mk2 GLOW PLUG RELAY 2.0 TDCi Diesel 9M5Q12A343AA 2010 13 14 15 (Fits: Ford C-Max) (1) 1 product ratings - FORD FOCUS C MAX Mk2 GLOW PLUG RELAY 2.0 TDCi Diesel 9M5Q12A343AA 2010 13 14 15 UK/Ireland Location: Sussex. Posted April 22, 2018. my understanding is as per Simon_k. glowplug light means wait for the glowplugs to get up to temperature. Light not coming on does not mean glowplugs are not on, it just means you don't have to wait for them to get up to temparture as there is no cold weather impeding them reaching temperature 1993 f250 glow plug relay clicking. I've had glow plug problems several times with my '90 7.3 E-350. This last time I found that two of the connectors (to the glow plug) were bad. You can check this by checking for continuity between the connector and the output post on the glow plug relay. 20 Years of ownership of a 99 7.3. 1999 - 2003 7.3L Power Stroke Diesel - Stancor 586-902 Glow plug relay - Anyone running the Stancor 586-902 GPR? Mine stock relay went bad and I replaced it and it’s not powering again and we think it’s bad (again) so I saw people were running the Stancor one. Who’s using and how’s it working for you. On modern diesel engines the glow plugs are not only used for starting the engine. The glow plugs are also used during normal operation and driving. The reason of this is to make the engine run smoother and reduce emissions. A defect of the glow plug system should generate DTC codes. Bugman. 7537 posts · Joined 2007. #3 · Mar 29, 2015. If you have power to the relay then you are not getting the ground that is supplied by the PCM. So it may be a PCM problem, a sensor problem, or a broken wire. 96 F250 XLT 4x4, 4:10 gears, 5 speed, Tymar intake and HX hose, downpipe, pyro and boost guages, coolant filter, LuK clutch. 1999-2003 glow plug control schematic. Working on a 2001 7.3 and I think I may be having an issue with the control module/relay for the glow plug relay. Wondering if somebody has the schematic for this device. Relay and glow plugs are new and seems to work when I apply 12 volts and I can measure voltage across the relay and see a voltage drop A failed glow plug will not cause this fault unless it has gone short circuit. 1) F2 in the fuse box in the engine bay. This should be 5A and is in the glow plug monitoring circuit. 2) F4 in the fuse box in the engine bay. This is a maxi-fuse and will be about 60A. 3) R4 in the fuse box in the engine bay. This is the glow plug relay. The connector which separates the glow plugs from the loom on top left rear of the engine has 4 terminals so could test from there, thanks for the ohms figure. I'll see if I can trace the loom back to the relay and will update later. gNGq6B5.