No start. Please help.

[the idiocracy]

67 inline 250. Aftermarket hi torque starter. Single purple wire to S terminal...nothing to the R terminal.

Drove to my kids school the other day, parked and when I came back out I got just a single click when trying to start. Did some fiddling there without success so i dragged it home. Good battery. Checked all fuses. Start Solenoid is what is clicking. So figured the starter Motor burned out. Ordered a new one. Just put it in.

Literally the same problem.

Anybody got any ideas on what could have happened? Is there a start relay somewhere in the purple wire circuit that I am missing? Could this be the ignition switch even though its energizing the purple wire?

Any help would be greatly appreciated. I'm stumped.

[franken]

Measure the voltage to the tenth across the battery and to ground at the S terminal when the key is in the start position. Chances are you need to charge the battery. Once it starts measure across the battery with the engine running.

[the idiocracy]

I'll do that tomorrow and let you know the results. Thanks Franken

[the idiocracy]

Okay, measured the Batt at 11.89v.

Voltage across the Purple wire to ground with key in START has a constant 8.5v.

Hooked up a charger and tried to start but no luck. Didnt think to measure purple to ground at key start with the charger hooked up.

Any thoughts?

[HO455]

I think that 8.5 volts at the starter solenoid is too low to get the solenoid to pull in. Try charging the battery overnight or using a charger with a good powerful start mode.

Another test to determine the conditions of the battery leads would be to put your voltmeter on DC volts and put one lead on the negative post of the battery and one on the starter body. Then try to start the truck while monitoring the voltage. You should not see any voltage. If you do then you have a bad ground wire or connection.

You can do the same with the positive post and the battery terminal on the starter. No voltage is good. This is the day you really appreciate having a nice straight six. Easy access to that starter.

[the idiocracy]

Originally Posted by HO455

I think that 8.5 volts at the starter solenoid is too low to get the solenoid to pull in. Try charging the battery overnight or using a charger with a good powerful start mode.

Another test to determine the conditions of the battery leads would be to put your voltmeter on DC volts and put one lead on the negative post of the battery and one on the starter body. Then try to start the truck while monitoring the voltage. You should not see any voltage. If you do then you have a bad ground wire or connection.

You can do the same with the positive post and the battery terminal on the starter. No voltage is good. This is the day you really appreciate having a nice straight six. Easy access to that starter.

The access is very nice indeed. Swapped the starter out in 20 min wheels up to wheels down. Gotta love that!

Thanks HO455. I'll run the checks you described tomorrow. I do also have two negative shunts (1 on the negative terminal and one in the cab...i had a voltage drain a few months back that I fixed recently). I'll remove those too just to be sure. Ill get back tomorrow night with an update.

[pwdcougar]

Originally Posted by HO455

Another test to determine the conditions of the battery leads would be to put your voltmeter on DC volts and put one lead on the negative post of the battery and one on the starter body. Then try to start the truck while monitoring the voltage. You should not see any voltage. If you do then you have a bad ground wire or connection.

Great idea!

I'll have to remember this!

Paul

[Bigdav160]

when I came back out I got just a single click when trying to start.

From this symptom, this is what I would do:

Check battery state of charge - which you have done. 11.9 volts is a very discharged battery. Charge battery.

Then I would put my voltmeter across the battery post and try and start. It should be 9.6 - 10.5 volts if the starter is trying to turn the engine. If the voltage is in this range or lower get a ratchet on the crankshaft bolt and make sure the engine is not locked up. Otherwise the starter (but you've already replaced that.) If the voltage goes really low then it's likely the battery is bad.

If the voltage in the above test is closer to battery voltage that means the starter isn't working. Place your voltmeter leads from the battery negative terminal to the engine block. Try to start. The voltage should be close to zero (preferably less than .2 volts).

Do the same on the power side. Positive battery post to the big post on the starter motor. Try and start. The voltage should be less than .5 volt.

The same test (voltage drop) can be done from the battery post to the connection terminals on the cables.

edit - speed reading. I didn't notice that HO455 had addressed the voltage drop on the cables routine. Also voltage drop measurements are only meaningful if the load in the circuit is actually operating.

[the idiocracy]

Big relief. Blown Motor was going to force me to put in a big block. So that would have been pricey!

And now I have a spare starter.