Problem: RPM Relay never shuts off after the car starts even when the engine dies. Tom Niemczewski wrote me off list and suggested I check out a few items in the RPM Relay schematic. I went through a few of them with no luck and tried experimenting to try to get to the bottom of this seemingly simple problem. After I tried and tried unsuccessfully, so I measured all the voltages at all the pins of the 555 timer. Then I sent an email of to Tom with the info. As I was composing that email I reviewed the data that I collected and one piece seemed to stand out. That was the fact that there was a constant 4 volts on the 6/7 pins of the 555. Since it was below the 2/3 of the 10 volt power supply it meant that the timer would be on. But this is a simple RC circuit and thus the cap voltage should rise until it reaches the 10 volt supply. Something was keeping it low and thus keeping the timer on. I scrutinized the circuit some more and realized that either the transistor across the capacitor that is connected to pins 6/7 was leaky or the cap itself was leaky. Since I had already replace the transistor, i replace the cap and viola! (Tom did mention the cap in his original reply to me but I couldn't believe it could go bad. Now I believe it.) I'm sorry if all this is too technical or boring for some of you but is just supports the fact that this group is a great bunch of people that spend a lot of their valuable time helping each other. So thanks Tom for your help on this one. (I still have that annoying tach flicker but hopefully it will be solved too some day.) D² and 6530 Dave Delman BTW Tom was not the only one to lend a hand on this one, Elvis was in there too. [Non-text portions of this message have been removed] To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/