Electrical basics

[Specialk]

Hi everyone!

Starting to feel like spring here so slowly thinking about getting my "mistress" (according to my wife, costs just as much in time and money) out of storage. Wanted to go through both Brad's & greg's tune-up manuels but have trouble with the multi-meter settings and knowing when to test for current, voltage or resistance. Could someone be kind enough to outline the basics to testing the electrical components? Also, on the FIs, is there any precautions needed prior to testing? Disconnect Ecu, battery, etc? Any help would be appreciated

Rgds

[TX82FIAT]

I've been thinking of how to help you out without writing a book on testing electrical circuits. As I run through hooking wires up across a circuits, testing for voltage and continuity I realized that this would be a big response. The first question is do you own a multimete and or test probe light. Please read the below attached articles and see if that helps get you started on testing circuits. A quick example, set a multimeter to volts and touch the positive end to the positve battery post and the negative end to the negative post. You have just tested a circuit and it will give you the voltage your battery is putting out. This is a quick test to see what voltage your battery is putting out for a point of reference.

http://www.freeautomechanic.com/wiringproblems%205.html

http://www.youfixcars.com/multimeter.html

[baltobernie]

Hey Mark; move this thread to "Electrical"

Are you trying to get your car to run, or have some of your accessories failed, or ...?

The battery must be fully charged and in good condition for any in-place electrical testing to be valid. You didn't state how long your car was in storage and what (if anything) you did to maintain the battery, so perhaps a good first step would be to remove the battery and take it to a local "big box" auto parts store, where they will test it, usually for free. Specialized equipment is needed to test a battery's health.

Next, check your charging system: http://easyautodiagnostics.com/alternat ... ests_1.php. Once you have tested and/or repaired the delivery system of electricity in your car, you can move on to the various components that consume electricity. Two things are needed to illuminate a bulb, turn a motor, etc. (1.) Proper voltage (2.) Sufficient current. With your multimeter, you can't measure the amount of current required to run most automotive electrical components, but you can measure voltage, and you can make some assumptions because the two are related. We can talk about this later, but ...

Common complaints on Spiders are "poor charging" and "slow wipers/signals-dim headlights etc."

The key here is to measure voltage at the destination. That is, if you are testing a headlamp, you should place your test leads at the lamp socket, not the fuse block or somewhere else "upstream".

This should get you underway. Re-post for assistance on specific electric problems.

[Specialk]

Thanks formthenreplies. Sorry, should have provided more details. Car was running OK, maybe a bit rich, prior to storage in November for the winter. However I wanted to work on the tunning and get a better feel for the car for the day that something does break. I also know that my cold start is not working but haven't had the pleasure of trying to track down the problem

Tried a few things this week-end with Greg's L-Jetronic manuel.
1. Battery is disconnected and out of the car
2. ECU is disconnected
3. Tested the CoolantTempSwitch. Reads 3.2k at 3 celcius.
Reading isn't constant, moves up & down as I hold probes to terminals; is this normal or what i''m i doing wrong?
Testing it at the ECU connector show no reading
4. Tested the air flow meter at the ECU connector.......first two reading in range according to Brad's document.
Nothing between terminals 8-9
5. Tested the full throttle switch, again nothing

My conclusion is that I'm still not up to par with using the multi-meter. Any help or easy tests to practice would be appreciated.

Rgds

[RRoller123]

Sounds like you have a connector or wire break problem with the coolant temp sensor, as you should be able to get a similar reading at the ECU, with just the added resistance of a few feet of wire, which is minimal.