Monday, September 29, 2014

1st week of fall 2014!

Well this first week of electrical has been a good refresher since we had it last year, and there was a lot of stuff that we digested this week. There are of course the staples that we've know. A short to ground is gonna blow a fuse, and should be replaced with a "fuse that glows" to locate it. A short that bypasses a switch is a short to power. If there's no current flow then there can't be a voltage drop. Also going to the most negative point in the system (-battery post) with you lead leaving you with just a positive lead and your meter. One thing I'm getting more respect for is the number of connections that can be in a circuit and therefore can become a high resistance connection.

Kirchoff's current law makes a little more sense now. They way it seemed to be really useful is to use it to find the source or the load. It can also be used to figure out which circuit your on, and what direction you're going in (to or from the source). Also current flow testing allows you to see work being done. The sum of current flow in a circuit should be the same throughout the circuit.

I found it interesting in one test board that the primary and secondary circuit both shared the same bad ground. This caused the relay to turn on and off repeatedly as the Fuel Pump would actuate and cause enough of a VD for the Relay to not be able to energize. This is why a relay buzzes and will continue on in a loop until the ground is fixed.

Going to add the pictures of the starting/charging  tests I did on a couple systems. Phone died.

When heads are re-manufactured they use baking soda to blast all the corrosion, carbon, and dirt off.


The areas that are critical are mainly the valve seats, intake ports, exhaust ports, and this main area here where all the moving valves, springs, and cam takes place. It literally must be spotless.