One of the glow plugs on my Universal M-18 completely shorted, causing the wiring to melt behind the engine panel, lots of smoke and plenty of headaches trying to repair and locate the cause. In stages, I replaced all the melted wiring behind the panel, ran new ground, amp meter and positive wires, new ignition and glow plug switch, trying to isolate the short, but the glow plug circuit still got extremely hot. What fooled me is that I could touch the tops of the glow plugs and they were hot, so I thought they were working, but could not start the engine. I noticed some deformation of the the wiring harness plugs where the positive and amp wires passed through them, which is why I ran new wires. There was no fuse at all, except on the solenoid start wire. I added a fuse to the positive wire from the starter solenoid post to the engine panel.
The advice and research from Mainsail, the Catalina forum and Cruiser's forum was a big help. I reasearched testing glow plugs and found that it is very rare that a GP will short to ground when they fail. Normally, just get weaker and finally quit working. $18.00 for two new NGK glow plugs at NAPA, and it started immediately.
I intend to get rid of the very long amp meter circuit and install a volt meter and a glow plug circuit relay or solenoid using Mainsail's upgrade procedure. Mainsail said these harnesses are dangerous and I'm a believer now. Please take the time to inspect your Universal wiring harness connector plugs and look for signs of hot wiring causing the plugs to deform. Here is a link to Mainsail's wiring harness upgrade: http://www.pbase.com/mainecruising/universal_wiring_harness_upgrade
Hope this helps,
Steve W
The advice and research from Mainsail, the Catalina forum and Cruiser's forum was a big help. I reasearched testing glow plugs and found that it is very rare that a GP will short to ground when they fail. Normally, just get weaker and finally quit working. $18.00 for two new NGK glow plugs at NAPA, and it started immediately.
I intend to get rid of the very long amp meter circuit and install a volt meter and a glow plug circuit relay or solenoid using Mainsail's upgrade procedure. Mainsail said these harnesses are dangerous and I'm a believer now. Please take the time to inspect your Universal wiring harness connector plugs and look for signs of hot wiring causing the plugs to deform. Here is a link to Mainsail's wiring harness upgrade: http://www.pbase.com/mainecruising/universal_wiring_harness_upgrade
Hope this helps,
Steve W