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Thread ID: 124160	2012-04-10 08:15:00	Ant auto sparkies here?	prefect (6291)	PC World Chat

Post ID	Timestamp	Content	User
1269113	2012-04-10 08:15:00	Got a bus to fix, its a Mercedes Benz but someone has put an Hino engine in it. Problem is when you are driving at random times the glow plug light comes on cycles a few times repeats etc. Know its not just the control circuit the glow plugs are going on because the voltmeter takes a little dip. It has an aftermarket glow plug/heater timer Got these connections Earth Ignition Glow plug indicator lamp Batt Another strange thing is there is no heat relay so the timer and its wire take a fair bashing I guess around 40 amps. It has a stupid after glow function so when the clock time is reached it makes a clacking sound and the lamp flashes. Had a gawk around cant find anything obvious to why it would turn on itself, no other circuit is playing up that I can see. Plan B is take the timer off and smash it then hook just push button and a relay with a dyna tape warning like Push for 10 seconds for cold start. Did a test start before stone cold and the engine flashed up ok. But knowing my luck if I didn't put a heat circuit the bus will got to the Chateau or something this winter and my name would be ****.	prefect (6291)
1269114	2012-04-10 10:08:00	Have you tried a voltage drop test? I have done + and - sides for fuel pump, starter, alternator circuits, etc, so probably can be done for glow plug to battery or somewhere within the controller circuit. Readings (i.e. drop) should be less than 0.5 V. Or ideally much lower.	kahawai chaser (3545)
1269115	2012-04-10 10:16:00	Thanks for reply, not sure a voltage drop test will give me the answer getting a little less than 2 Volts drop when the heat goes on. Thats from 14 volts when the bus is going full noise so alternator would be smacking out 100 Amps. Gauge isnt that accurate. Mate rung me before saying only this could happen is if the ignition circuit or wire from is dropping off power and going back on again like a bad contact. If all ignition power was lost the gauges and other stuff would fail as well but they are not drooping off line, the wires are all joined to one post on the ignition key unit. Thats how the thing works you turn the key on to ignition and wait for the noise and flashing to stop then keep turning the key to engage the starter power. I might change the wire from the ignition key unit to the timer and take it for another blat.	prefect (6291)
1269116	2012-04-10 11:57:00	First thing I'd check is the battery connections, leads & earth contacts. Crank the engine over for a few seconds without starting the engine if poss half a dozen times. If the terminals or wires heat up & sometimes they get hot enough to burn you, replace as necessary. Check engine to body earth connection, make sure its good, has a nice thick lead & doesn't get hot. Check the ignition switch itself to make sure it's not making & breaking from getting jiggled about when driving. A test light to each output in turn & give the electrical part of the ignition switch a good workout, you know what I mean. If its flickering, replace the switch. Check that out first before condemning.	Phil B (648)
1269117	2012-04-11 00:14:00	Found it was the timer. Bench tested it with a dummy load (old headlights with low and hi beam joined). Did the same thing touch it or on its own it will start cycling. Easy fix put it under the forklift wheels. Thanks for help	prefect (6291)
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