Starting issue...

[mojo9430]

Hi... I have a 1990 240sx, manual trans. When I go to start it it cranks slow then clicks. Battery is charged, checked for parasitic draw (none), starter checked out and is good. I can turn the starter over fine if I put a jumper on the ignition wire (the thin wire on the starter) and connect it to the positive terminal on the battery. Once I hook the thin wire back up normally it does the slow crank again. Could it be the ignition switch itself, or the clutch safety switch? Thanks...

[Dboyizmlg]

Sounds like it may be the alternator.

[mojo9430]

Well, yesterday I was able to get it started and checked the output of the alternator and it was 14+ volts. Could there be something else wrong with the alt to cause a slow cranking problem?

[boosted KA24DE]

Just because the battery is charged doesn't mean it is good. The battery may not be able to put out enough cranking amps to start the car. i had this problem a couple of years ago and replacing the battery with an optima yellow top worked out great for me. You need to try another good known battery.

[mojo9430]

I'll try that Boosted... Wanted to see if it was possibly something else before spending $$ for a brand new battery... Thanks...

[mxexux]

You already found the problem but didn't realize it. That wire that you jumpered probably is bad. High resistance in the cables going from the battery to the starter will cause this symptom.

You can check for high resistance by measuring voltage drop from one end of the cable to the other. It should not be more than half a volt.

[So Make Like]

if in question, load test the battery. parts stores should do it for free. and as already stated, that starter wire needs to be traced and inspected. sounds like it's fraying or something.

[inopsey]

You already found the problem but didn't realize it. That wire that you jumpered probably is bad. High resistance in the cables going from the battery to the starter will cause this symptom.

You can check for high resistance by measuring voltage drop from one end of the cable to the other. It should not be more than half a volt.

you can also test the wire for resistance/corrosion with a mulitmeter on ohms

[mojo9430]

Thanks... I'll double check all the wiring again tomorrow before I get a battery. I'm sure there is something I missed. Thanks again for the free advice guys

[mojo9430]

Checked the wiring, everything checked out... Gonna plunk down some cash and get a new battery...

[So Make Like]

don't buy a new battery without testing it first.