supercub wrote:
Thanks for the input...........Easist fix I have ever had.............I just held the switch down a little longer and ..........presto.........it started LOL.
Thanks for the suggestions.
Brian
Brian,
You don't say what coach, model, year etc. The Onan 7.5QD (and just about any other model of Onan RV diesel gen) is governed by a small ECM that controls all of it's operation. And, not only that but, there is what's called a temp sensor in the cooling system that, sends signals to the ECM, telling it what present operating temps the engine is at. That temp sensor not only sends signals for COLD operations but, also HOT ops too.
The little Kubota engine that powers the Onan QD is a 3 cylinder, 14 HP engine and, uses "Glow plugs" for preheating the cylinder combustion areas, prior to starting, especially in colder weather.
There is a time delay chart that Onan prints in it's maintenance and ops manual that tells how long the glow plugs must be heated, prior to the starter receiving a signal, to start to turn the engine over.
The colder the climate, or, ambient temp, the longer the glow plugs must heat, prior to cranking. I've posted the chart several times. And, it's not MINUTES. The max time for glow plug heating is around 15 seconds or so. So, in colder conditions, as in say, oh, about 40 or so degrees outside, the starter button must he held for the longest time frame in the chart, before the ECM, will allow the engine to be cranked over. The warmer the climate is, the less time for heating. As in, if it's around say, 65-70 degrees outside (which would mean the coolant in the engine is about the same temp), the glow plugs will not need preheating, the starter will engage immediately when the button is pushed. Hope this clears things up a bit.
Scott
