Camo wrote: ... Applied 12 volts dc to the wires (2 wire solenoid) and it clicked. Read 021 ohms with my multimeter set to 200 ohms across the posts with it energized. Read 039 ohms with it set to 200 ohms across the 2 wires without it energized...
The resistance of the start relay coil when energized vs when de-energized is unimportant.
A starter relay on old Kaws has two sets of two terminals:
The 2 smaller ones energize the electromagnetic coil inside the relay. On a Z1 start relay these terminals have small (~16ga.) wires soldered to them that aren't easily changed. These two smaller terminals are connected to the handlebar start switch circuit. Note that the start relay coil is likely to have very low resistance, on the order of ~3.0 ohms or so. This is important as we shall see shortly.
The two heavy terminals on the start relay are used to supply direct battery power to the starter motor when the start relay coil is energized by pressing the start button. When the relay coil is energized, a pair of heavy contacts inside the relay close, completing the circuit from battery to start motor. One of the 2 heavy terminals are connected to the battery (+) via a heavy cable, the other heavy terminal is connected to the starter via it's heavy cable.
When using a Digital Multimeter (DMM) set to 200 ohms one must first determine the native resistance of the DMM's leads themselves., because most inexpensive DMM's cannot be precisely zero'd.
We don't know the details of your DMM, so we'll safely assume one thing: with the meter set to 200 ohms
and the probes not touching the display is likely to read either "1 ." with the decimal a few places to the right or, simply, "OL". This is open circuit i.e. no current can flow. Now, touch the probes together firmly. This is closed circuit; current can flow. Wait a few seconds for the display to stabilize. You're likely to see a reading in the neighborhood of 5.xx ~ 6.xx ohms, although there may be a little drift or "noise" in the digits to the right of the decimal, which can be ignored. This is the
native resistance, in ohms, of the meter and it's leads, and can be considered zero ohms for our purposes of testing a start relay and most other things. Make a mental note of this reading.
Now, with the small wires (start sw. circuit) disconnected from from the rest of the bike, place one DMM lead on each small terminal of the start relay. On a Z1 relay I see a reading of 9.xx. Subtracting the
native resistance from this reading, we arrive at a start coil resistance of ~3.xx ohms or so, which is what is to be expected.
Testing the start relay for the
starter motor circuit itself is only slightly more involved, and a helper might be useful.
Disconnect both heavy cables from where they're attached to the posts on the start relay. With the DMM set to 200 ohms, touch one lead to one of the heavy posts (doesn't matter which) and the other lead to the other heavy post. There should be no significant change in the DMM display (1 .) or" OL". Carefully apply battery power to the
two small leads on the start relay. This should energize the relay coil, which closes the heavy internal contacts that apply battery power to the starter motor. If the relay coil is good you'll likely hear a "click. Hearing a click doesn't necessarily mean the heavy contacts have closed electrically, it just means the coil is energized. Now, with the coil remaining energized. touch the leads the DMM leads to the two heavy posts again.
If the internal contacts are good, you should see
native resistance or
very slightly higher on the display, indicating a closed circuit. This is what would be expected with a good start relay. If the resistance is significantly higher, that would indicate burned internal contacts, necessitating replacement of the relay.
A good tutorial on basic DMM use can be found here. Fair warning - browsing the lygte.de site might lead to an addiction to high performance LED flashlights. Don't ask how we know...:
lygte-info.dk/info/DMMComponentTesting%20UK.html
Good Ridin'
slmjim & Z1BEBE