Intermittent FULL Electric Power Cutout when trying to start

- I posted recently about an issue with won't-idle upon start. Haven't done
any diagnostics on that, so still not sure what it is.


NOW....I do have another issue, and am not sure if the two are related/same cause, or not.

The second issue is a FULL loss of power, when first entering the rig to start the plant. Just plain dead. (New Odyssey battery, recently, so that's not it) It's strange, as it is just periodic; and the power will come back just by working the dome-light door switch. Today, after doing just that, when it still had no start power, I simply popped the hood latch, and it had full power. Thus, that bit of an impetus affected something...?

COULD the NSS be the cause of both problems? I was told that, not uncommonly, a replacement NSS can need to be lubed and adjusted at some point moving forward.

Any insights and input will be appreciated, thanks.....

Both symptoms point to low voltage due to:

• a failing battery
• a failing alternator
• dirty, corroded, or loose wire connections
• internally corroded battery wires

A faulty NSS simply causes the starter to not engage.

Perform routine maintenance of the start and charge systems. Remove, clean, and firmly reconnect all the wires and cables to the battery, starter, and alternator. Look for corroded or damaged cables or connectors and replace as needed. Copper wires should be copper color, not black or green. Do the same for the grounding wires from the starter to engine block, the ground wires at the coil, and the ground wires from the battery and engine to the Jeep's frame/body. You must remove, wire brush, and clean until shiny the cable/wire ends and whatever they bolt to.

Jeeps do not tolerate low voltage, bad connections, or poor grounds.

Place your DVOM (Digital Volt Ohm Multi-Meter) on the 20 volt scale. First check battery voltage by placing your multi-meter's positive lead on the battery's positive post ( the actual post, not the clamp ) and the negative lead on the negative post. You need a minimum of 12 volts to continue testing. Next, leave your meter connected and take a reading while the engine is cranking. Record this voltage reading. Now connect your positive lead to the battery terminal stud on the starter and the negative lead to the starter housing. Again, crank the engine and record the voltage reading. If the voltage reading at the starter is not within 1 volt of battery voltage then you have excessive voltage drop in the starter circuit.

Typical voltage drop maximums:

• starter circuit (including starter solenoid) = 0.60 volt
• battery post to battery terminal end = zero volts
• battery main cable (measured end to end) 0.20 volt
• starter solenoid = 0.20 volt
• battery negative post to alternator metal frame = 0.20 volt
• negative main cable to engine block = 0.20 volt
• negative battery post to starter metal frame = 0.30
• battery positive post to alternator b+stud = 0.5 volt with maximum charging load applied (all accessories turned on)

Test the output at the alternator with your volts/ohms multi-meter. You should be measuring 13.8-14.4 volts. Load testing the alternator is still recommended.


Have your helper turn the ignition key to START while you tap on the starter with a hammer. If the engine starts, you probably need a new starter.

Have the battery, starter, and the alternator Load Tested for proper function in a test machine that applies a simulated work load. Handheld testers are inaccurate and will often pass faulty parts.

For 1996+ Jeeps, the OBD-II engine computer (ECU/PCM) re-boots, and the idle settings are deleted, when you: (1) let the battery run down by leaving the lights or radio on, (2) disconnect the battery for an extended period of time, (3) when the battery goes bad and needs replacing, (4) when the alternator is not properly charging the battery, (5) or when poor battery connections result in a voltage drop at the PCM or poor battery charging.

Loose, corroded, or damaged battery cables or ground wires may also cause or contribute to the problem.

Your symptoms are: (1) having difficulties starting the engine without depressing the gas pedal, and (2) the engine will have a low idle and probably stall unless you keep your foot on the gas pedal. (3) The ECU will relearn the idle settings after a short period of driving and the engine will start and idle normally.

Thanks very much, Tim_MN

I do recall refreshing the engine-to-firewall ground strap connections several years back.

Battery and alternator (modded, H-O unit) were recently tested as working fine. Battery SHOULD be fine, as it's new and a quality unit but, of course, nothing is 100% dependable to be good-out-of-the-box.

I'll clean and refresh all critical wiring connections, as it's good to do anyway, and will check voltages. Hopefully, that's the issue but, again, not a waste of time to do, even if not so...

Again, thanks.

Mine did that and a good cleaning of the battery terminals fixed it right up

962door said:

Mine did that and a good cleaning of the battery terminals fixed it right up

Click to expand...

I have had this happen as well on an old Honda I had, negative battery terminal clamp was "worn out" and not tightening enough. Intermittently when I would go to start the car everything would shut off. Before I tried to start it I could turn on the headlights and radio however.

One way to check is to twist the terminal clamps to see if it makes a better connection, mine were slightly oblong so twisting them would get me the improved connection necessary to start the car. If that fixes it, you should be looking at getting a new cable, otherwise start checking other grounds.