I've been trying to get my long-suffering Toyota RAV4 first generation (1998) to start after numerous different problems, the latest of which I've narrowed to the spark plugs not firing seemingly due to no power reaching the spark plug wires.
So, my next problem is figuring out why no power is reaching the spark plug wires:
- I've checked all the fuses (even ones unrelated to the problem), and tested them all with a multimeter even when they look fine.
- I've checked and tested the main relay out of the car (though I guess it's possible there's a problem with the connection to and from the relay?)
- The battery, starter motor, dashboard, fan and fuel pump all appear to be working fine
- The spark plugs themselves are new, don't appear to be damaged (though I'm not exactly qualified to judge). A little bit grimey, maybe, but doesn't appear to be enough to cause a problem
- The "check engine" light doesn't come on while I'm trying to start the car. I know in some models, this indicates no power to the ECU, I can't find confirmation whether that's also true for old RAV4s (and I can't remember if it came on when starting the car before). Nothing in the owner's guide or that I can find online.
I've got an electrician coming to look at it, but I've been warned by many car owners who've been in this country (Sierra Leone) longer than I have that car electrics is the biggest skills gap the largely self-taught local mechanics have, something I've seen evidence of already, e.g. none have been able to make any progress at all with this dashboard problem, and I've found many worrying things like blown fuses "fixed" by wrapping copper wire around the connections (I replaced all these immediately!).
I'd like to at least be able to do some investigation of the problem myself and if I can't solve it myself at least be in a better position to supervise.
Update: I think I've fixed the original problem that was causing me to check the power to the spark plugs, but it's absurdly specific to the hazards of car ownership in a 3rd-world country, so it's not likely to be much help to most people interested in this sort of diagnosis! The details are here on my answer to my original "car won't start under strange circumstances" problem (basically, the fuse socket's connection to the ignition system was lost due to bits of broken copper wire stuck deep in the socket, from an earlier broken fuse having been "fixed" with wire under a previous owner).