car electronics 101

Hi all I am new to the form. I know engines quite well but I would like to sharpen up my electronic/electrical knowledge.I would like to learn things like if I do a engine swap will my gauges still work,how to to make my own engine harness,how the different sensors work(from an electrical/electronic stand point)....etc Can someone please help me to learn this. Best regards L_O_O_M

You could start with www.bcae1.com. That's a popular reference and covers most things. And unlike many web sources, I have little disagreement with what it says. As to gauges and sensors etc, meters and ECUs are matched to a particular sensor. EG - an older mechanical temperature meter might have required a sensor that is 7Ω cold to 112Ω @ 100°C. Another sensor with a 40R to 150R range would read incorrectly. (Note that "R" is often used instead of the Ω symbol - both because it's easier to type, and also because Ω can show differently in different browsers etc; one common translation for Ω being "W" which gets very confusing since a 2W resistor is just as valid as a 2Ω resistor.) Similarly for electronic meters or gauges, though they may have the possibility of being reprogrammed for the new sensor range. A conversion that I am often involved with is fitting or upgrading ECUs (EFI) to older EFIs or carburetted vehicles. The golden rules there are to get all the sensors that the donor vehicle/EFI uses, AND its sub-loom. Although such looms can be made up and sensors can be converted electronically, you first need all the required data and knowledge, and parts & connectors etc, and then all the work involved. (And then the nightmare of finding the cause of the fault if it doesn't work!) Treat engine swaps the same way. Transplant its sensors with that of the original vehicle unless you know otherwise, or also change gauges, and wiring, etc. I'd also suggest google searches for the specifics of what you want, but be wary of some info. IMO these days there is far more misinformation than good information. Some sites or forum replies even seem to have a vested interest in misinformation - whether to uphold someone's ego or to sell things to the gullible. FYI - this site is one that I highly recommend. Any falsities are usually corrected quickly. There may still be differences of opinion, but they often show alternatives or, in some cases, the extra experience of some. Some info is also subject to experience. A typical example may be one of my favorite subjects - the paralleling of batteries. Some say it is ok, but I reckon they have been lucky enough not to have yet had the problems that so often occur with others. (Hence the need for isolators that isolate the batteries when NOT being charged (or required for the specific load). That subject also highlights a common con (IMO) - namely the requirement for "smart battery isolators", and - in the specific case of Australia - the need for dc-dc converters to enable the charging of the extra batteries. The latter is a great $200-$400 con (in most circumstances) whilst the former is surrounded by crap including "priority charging" etc which is generally totally nonsense designed to explain a undesirable requirement of smart isolators. For vehicles with a charge light, a mere relay does all the required battery isolation and is much cheaper and superior to any voltage sensing or "smart" isolator. Apologies for my long reply - aka ramble (but that's typical for me LOL) - and my arguably self indulgent battery isolator rave. I take it that you are familiar with electronic/electrical things, but otherwise bcae1 has the usual basics including the water analogy for electricity. I'll often go deeper - eg, whereas so many seem concerned whether electricity is the flow of positive or negative particles (ie, electrons, or +ve & -ve ions; FYI - it is both!), I instead see charge movement as an effect or result of electricity. Yes, electricity needs free charged particles to "flow", but it is not the flow of those particles that is "the electricity" itself. VIZ - electrons flow at maybe a few meters per second whereas electricity travels at the speed of light, or about 2/3rds the speed of light thru conductors etc. It's a bit like sound traveling through air or water - the air or water does not itself travel (other than slight displacement). But whoops, there I go again. Typical me! But heed what others hereon say. They truly impress me and astound me with their knowledge and specific detail. (And I am not easily impressed.) Others will probably reply with other or better references. And probably do it in less space! Best wishes. PS - don't assume car manufacturer's always get it right. I've seen lots of OEM stuff-ups like switching & relay configurations and aspects of engine control (eg, the use of oil-pressure to control electric fuel pumps). Whilst many such things have since been ironed out, there is still the new wave... EG - ECU control of alternators which - whilst good for performance (acceleration) is IMO not a good design and leads to greater fuel consumption. As to modern bus control (CAN etc) and security...

Hi oldspark WOW didn't expect such an awesome reply,thanks for the link and I actually enjoyed all your ramblings I find it interesting. Regards L_O_O_M

oldspark wrote: As to gauges and sensors etc, meters and ECUs are matched to a particular sensor. EG - an older mechanical temperature meter might have required a sensor that is 7Ω cold to 112Ω @ 100°C. Another sensor with a 40R to 150R range would read incorrectly. (Note that "R" is often used instead of the Ω symbol - both because it's easier to type, and also because Ω can show differently in different browsers etc; one common translation for Ω being "W" which gets very confusing since a 2W resistor is just as valid as a 2Ω resistor.) Similarly for electronic meters or gauges, though they may have the possibility of being reprogrammed for the new sensor range. A conversion that I am often involved with is fitting or upgrading ECUs (EFI) to older EFIs or carburetted vehicles. The golden rules there are to get all the sensors that the donor vehicle/EFI uses, AND its sub-loom. Although such looms can be made up and sensors can be converted electronically, you first need all the required data and knowledge, and parts & connectors etc, and then all the work involved. (And then the nightmare of finding the cause of the fault if it doesn't work!)

Hi oldspark that is the kind of things I want to learn,where can I learn that sort of thing please(form you)?

If you mean specifics, then no - I'd have to look it up as would you. The rest is already out there and available. When you have a specific question, post it and we'll see.

Hi oldspark,where can I read more about how sensors...etc works like you talked out "an older mechanical temperature meter might have required a sensor that is 7Ω cold to 112Ω @ 100°C. Another sensor with a 40R to 150R range would read incorrectly. (Note that "R" is often used instead of the Ω symbol - both because it's easier to type, and also because Ω can show differently in different browsers etc; one common translation for Ω being "W" which gets very confusing since a 2W resistor is just as valid as a 2Ω resistor.) Similarly for electronic meters or gauges, though they may have the possibility of being reprogrammed for the new sensor range. "?

Didn't you find it on bcae1?

Which section?

It depends on your question. If you mean what vehicle has what sensor etc, then that's from its specs or workshop manual or spare parts book (cross correlated with parts specs). If you mean that sensors etc change, well, now you know. Parts can vary between models and even for the same vehicle depending on production time etc. That things can be designed or reprogrammed should be commonly known, but requires specific knowledge to action. And Rs & Ws & Ωs is experience or good IT training. I can't be more specific than that. There is no one place that I have learned. Most is self learned whether from books & libraries or people I have been lucky enough to cross in person or here etc. Surprisingly little is from formal education despite it consuming a lot of time, though it has taught fundamentals (language, arithmetic etc). My best "development" has been thru the ability to think and brainstorm. Sure, that requires supporting fundamentals, but it also means you can predict rather than follow technical trends. (Not that I recommend prediction - that carries a high price which is not refunded when it finally appears!) Two valuable lessons from my early working and later university experience... It's not what you know, but how you think (around the problem)   {from an automotive panel shop - a truly "lateral thinking" experience}; Two people each knowing 5% can work out 95% - that's from 2 students that didn't attend classes getting together a day or 2 before the final exam. I won't mention the other student's name. These days all the above can be done from an armchair or roof of a bus. Just google. Even the basics and fundamentals can be found. And it's still a case of "evolving" from those sources - whether it be wrong text books or wrong practicals and (their wrong) exam answers at university. The problem is that incorrect info was once rarer. Now it seem to be the norm.