My Bentley service manual cautions to use a meter (seems to be inferring DMM) of at least 10 megaohms input impedance to prevent excessive current draw that possibly might damage "sensitive electronic components."
I'm looking to buy an older 2-chan scope, and am finding most are rated a 1 megaohm.
Is the Bentley caveat referring mostly to ECUs? Among a long list of items, I would like to measure a load freq output of the ECU, along w/such things as fuel injector PW, knock sensor VAC output, primary and secondary ignition (using a capacitive pickup and correct attenuation probes), O2 sensor, alt AC ripple, Hall-Effect sensor, Air Mass Meter, fuel pump - basically as much as I can
Car is a 91 Saab 900: one fuel and one ignition computer (2 total), hot-wire air mass meter, solenoid injectors, one coil, distrib cap and rotor
I've seen leads that change pf. What components shouldn't I use a 1 megaohm scope on (trying to determine how useful/restrictive scope use would be)?
Thank you Lance