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Electrical Component Checkup for Nonstarter

Electrical Component Checkup for Nonstarter

Randy Wilson

The real test is with a VOM (volt meter) with alligator clips on the leads. You need to have over 8 volts for the starter to function; preferably well over 8, like 10 or 11. This is with the motor activated.

Set the meter in the windshield, propping it with a wiper blade, such that you can read it from the driver's seat. With each test connection, key the starter and read the voltage. We'll move the probes around to isolate the bad connection/component.

  • Meter connected to battery. Less than 8 volts, bad/discharged battery. stop. 10-12 go on.
  • Meter connected negative to starter (mounting bolt is good), positive to the lower big lug of the solenoid; actual power into the motor. 10-12 means bad starter (stuck brush). Stop. Below 8, go on.
  • Move positive to small screw wire (field wire). Below 8 volts, bad relay, neutral switch, ign switch. 10-12 go on.
  • Move positive to big top lug, battery in to solenoid. 10-12 v means bad solenoid. Below 8 go on.
  • Move negative lead to cylinder head. 10-12 means bad starter ground. Below 8 go on.
  • Move negative to car body. 10-12 means bad engine ground strap. Else go on.
  • Move negative to battery. 10-12 means bad main ground cable. Else...

Inspect the two positive cables and clean everything. A common failure point is the main power distribution junction block. It's a bolt lug with multiple wires on it beside the battery. Hard to test this particular area as there are several wires stacked... and a bad connection can happen any where in the stack.

If the test proves it's either the solenoid or motor itself, try giving it a good thump.


Jan Wikstrom
Elizabeth wrote: My battery is healthy and no, the starter is not cranking the engine, nothing happens when I turn the key.
    Here's another simple test procedure:
  1. Make sure the T-bar is in Park.
  2. Turn on the ignition
  3. Pull the heavy white-with-red-stripe cable off the starter relay (on the firewall above the back end of the right cylinder head)
  4. Touch the connector of this cable to the large brass screw with cables on that sticks out of the firewall about eight inches down and outward from the relay. This is a direct unfused battery (+) terminal. The starter motor should crank and the engine should start. If
    • the starter cranks the engine: you have a break in the circuit going battery - safety interlock switch - ignition switch - starter relay. The fault is probably in the wiring, but it can also be in one of the switches or the relay.
    • the starter doesn't react or clicks but doesn't crank the engine ->5
    • the starter cranks the engine but it doesn't start: do the ignition test.
  5. Put a voltmeter on the cable terminals at the battery, verify about 12.5V (healthy battery) and try again. If the voltage
    • stays near 12.5V: the starter solenoid doesn't close its contacts or the starter motor winding has a break. Either way, the starter needs to come out. Yes, there *could* be a break in the main cable to the starter, but that's most unlikely.
    • drops below 4V ->6
  6. Connect the voltmeter directly to the battery posts (not the cable terminals) and try again. The voltage
    • drops very little: your battery terminals need cleaning.
    • drops below 4V: your battery is feeble through old age (high internal resistance). You need a new battery.

Good luck, again. ** Two wrongs don't make a right. Try three. **


Bob Buchenan

I don't remember the full extent of the problem but heres some ideas (read random thoughts :-) )

I am going to have to speak generically, as I am not familiar with the s2 (I own s3 xj6) and my wiring diagrams only go back to 81.

If problem is persistant. Actually, I mean not intermittant.:

  1. Check power to the terminal which closes the solenoid. The one from the key switch. Attach a meter or test light to the terminal as see if it flashes while the key is turned on and off. Also, check the wire and the terminal seperately to see if contact is being made between the two.
    • A. If power is being supplied, check power going out to starter. Check at both end of the cable.
      • If power being supplied try jumping starter over with a lead diertly from the battery. Use a good new peice of wire. this should tell you if the cables are wiped out and need to be replaced. This does occasionally happen as wires oxide and lose conductivity.
      • If no power being suppliedtry substituting a new solenoid in as this sounds like the problem.
    • B. If no power being supplied at solenoid from key switch, check to see if power is being supplied from switch at other end of this wire (the spot where it comes off the key switch) If no power here key switch sounds bed. If power here wire between key and solenoid bad.
  2. If above is ok. check power from battery to solenoid. (starter cable). Actually you should do this first since it doesn't take as long. Also, try jumping direct from battery to starter to rule out starter cables before investing time in the the key switch circuit.

If problem is intermittant. The same procedure should hold true. You will just have to keep turning key until starter doesn't spin and watch the meter or light at that time.

I liken the flow of electricity through wires to the flow of water through hoses. It goes in one end and comes out the other. If it isn't coming out, either it's not going in, or the hose is plugged (broken wire or resistance to high). Basically the starter solenoid is like a valve being turned on by the key switch (another valve).

Tracing electricity through a circuit is not difficult. It just NEEDS to be done systematically. Start at one end of circuit (it doesn't matter which) and move progressively to the other end, checking both ends of each wire. At some point you will lose power. Then you know the component that has failed. Not difficult, just time consuming.

I would suggest starting the tracing over. Assume NOTHING. Work deliberately from one end to the other as I have described. I know that this sounds as if you are rehashing what you have already done but the answer has to be there. But it cannot be found by jumping from one spot to another. I once pulled my hair out trying to figure out a no spark problem. Didn't follow this advice and assumed some things that were wrong. As it turns out, while I was doing something else I had a friend make a new wiring harness on top of the engine to replce some wires with cracked insulation. We kept both ends of the original wires as they were still in good shape. This way when the new harness was all taped up, the original wire colors were still exposed so harness could still be traced with factory diagram if neceassy. Anyway, the positive and negative coil leads got crossed in the new harness. After hours of frustration, I cut open the harness out of couriosity and there it was! Threw a test meter on it and BAM it showed right up.

Thats enough rambling for now. I hope I didn't scare or confuse you. It really is to bad to do. Electricity used to scare and CONFUSE me until I thought about the hose and water theory, then it made more sense.

Best of luck. If I can be of further help let me know. (I am ASSUMING that this was a help :-) )

Regards,


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