Where did the volts go? New symptom after starter replaced

[1981fiberform]

Had my twenty year plus old starter die at Lake Powell - fortunately on the last day. The starter would still spin when you turned the key but the engine wasn't turning. Brought it to Tucson Alternator exchange and they learned me that this old starter used a centrifugal clutch that mechanically disengaged when the motor would fire and increase the rotation speed versus having the solenoid disengage the gear from the flywheel. The problem was a gear or connection inside that clutch was broken so my motor would still spin but the gear that connects to the flywheel would not. So I bought a new starter and put it in and it doesn't start. Checking with a voltmeter when the key is turned to start I only get 4.5 volts at the starter switch solenoid input and about 5.5 volts at the solenoid return post. Jumping from the main input of the solenoid to the switch input does operate the starter. So the problem is not the starter but appatently now my switch wire doesn't have enough volts??

Soooo since it operated a starter before I took the wires off - any guesses on why I only have 4.5 volts now? The Starter SW wire (very nicely labeled by Fiberform by the way) was taken off the old post and put back on. Seems odd that my ignition switch or other failure would show up just because I took it off one starter and put it on another.

Had enough reaching under the engine for one day hoping to have a game plan in a few days when I take it on again

 

[StingrayMike]

Not sure if related, but I replaced the starter on my volvo 5.0 gxi. New starter was labeled abit different. The solenoid posts were labeled "h" and the other was blank. I assumed "h" was hot, for power. Nope. the other post was for power.
could your new starter be wired the same?

 

[gm280]

1981fiberform, not sure exactly what you are saying. Are you saying that the wire coming from the key switch to the starter solenoid small terminal has +4.5 volts on it when you turn the key to the start position? If so, you could have a bad key switch. Because the other small terminal on the starter solenoid should either be going to ground, or going to ground through a safety neutral switch. Either way, if the starter solenoid isn't pulling in and allowing the huge flow of current to flow to the starter, it will never start. One other thing you can check as well and that is the battery connections AND the negative connection at the engine itself. Too many times folks over look that ground connection because it is basically out of sight out of mind... JMHO!

 

[1981fiberform]

Thanks GM280. Yes when the key is held to start there is only 4.5 volts at starters Switch post and over 12V at the main. The "other" small post (return) goes to the choke on this old boat and should be half the battery voltage when starter is engaged so it seems ok. What was confusing was the starter I pulled out was turning-it had an old mechanical clutch that had broken so the engine didn't turn but the starter would spin. So it made no sense that suddenly the switch volts were low with the new starter. Verified yesterday that there is only about 5 volts on the switch post of the key ignition switch when the key is turned. Apparently that was enough for the old starter which does have a much smaller solenoid. I will follow up when I get the new key switch in.

 

[Bondo]

Ayuh,..... What motor is this yer workin' on,..??

Fiberform builds hulls, not drivelines,....

Without more info, I'm guessin' yer dealin' with corroded wirin' connections,....

 

[1981fiberform]

Sorry for the omission. AQ200D Chevy 305. Since I verified with my voltmeter there is 12v supplied at the key and only 5v leaving on the switch post of the key I am going to put in a new key switch and see. If that doesn't fix it I will run new wires rather than search old ones for damage

 

[Lawnpro979]

I'm wondering about a relay? not too sure about the old starter, and or if it has a type of built in relay?