DF90A starting problem

[Gringo]

okay, I went though the procedure. Removed the starter and magnetic switch. Took it apart. Everything is clean and in spec. Looks like new, in fact. I still checked the solenoid etc. All okay.

Then I clamped a battery to it, and shorted the relay terminal, and the starter spun like crazy. I didn't have any way to measure the 90 amps, but it sure acted like a new starter.

So I put it all back together. Same issue, like a weak battery.
I took a set of test leads, and went directly from the battery terminals to the two connections on the starter. Paralleled the normal cables. Left those in place, just gave the 12 volts another path to the starter. Turned the key, and it fired right up.

So, I'm puzzled. Good to know the starter is okay, the engine runs, etc. But I can't start it normally.

[noelm007]

OK then lets see, you bypassed the main battery cable and it works, does that sound like the cable is bad to you??? it sure does to me.

[jHydroman]

You are making progess, I would suggest that you check all of the crimped log at the termination of each cable for any signs of corossion. You can check the voltage at each connection starting closest to the battery.

Jim

[Carpenter]

Had the same thing happen to me in a new ford truck with 15,000 miles on it in 1988. The main positive cable going to the starter was pinched or almost cut through on purpose or was an accident. The cut was located under a clamp that secured the cable to the frame on its long twisted path to the starter.

It took a year for it to get bad enough to give troublre and was intermittent. I would open the hood and give my self a jump by jumping the bad cable with jumper cable.
It sure made people scratch there head thay wittnessed that.

[Gringo]

OK then lets see, you bypassed the main battery cable and it works, does that sound like the cable is bad to you??? it sure does to me.

Where did you think you read that? That's not what I wrote at all. I did not say that I "bypassed the main battery cable". I paralleled it with two light test leads for a voltmeter. Small wires with clips on the ends, and no where near enough copper to run the starter through them and it would have melted the little alligator clip off the end of that #16 wire in about a second if it dumped 12 volts at 90 amps through through it. It didn't even get warm.

Now it gets even hinkier. I removed the clip leads, which returns this all exactly to the way it was when I started. And now the key starts it.

I haven't fixed anything, replaced anything, or modified anything. But now it seems to work.

When I was trying to figure it out yesterday, I clipped a completely fresh battery to the same terminals using standard jumper cables. That didn't affect the problem. So...what is it about a couple light clip leads that made it start?

I need to figure out why it's doing this. I live in a very remote little country. No Coast Guard. No Sea Tow. I can't be having a motor decide if and when it wants to start.

[redlowrey]

I told you it was only voltage drop learn how to use a multimeter properly and you will find simple problems like that in five minutes.

[Gringo]

I told you it was only voltage drop learn how to use a multimeter properly and you will find simple problems like that in five minutes.

You don't seem to be able to read and comprehend my English, for some reason. Your comments, while I'm sure were well intentioned, assume the problem was found and that it was a voltage drop. I know that reading a voltage off a digital meter with a rotary switch and two wires (black and red, right?) might seem the height of technology to some, but it's really not rocket surgery for most of us, now is it. There was no explanatory voltage drop measured. It's essentially the same at the battery as it is at the starter terminals, only slightly less. That's expected due to line loss and resistance. There's nothing down near the 7 or 10 volts you have hypothesized.

The problem has not been found. Nothing has been modified, repaired, or replaced. I'm still trying to determine what is causing this.

Thanks for trying to help, anyway.

[redlowrey]

You pulled the starter off when you did not have too and found that it worked fine, what's that tell you find the problem yourself smart arse.

[noelm007]

The voltage needs to be measured with the starter engaged, just measuring the battery, and then the starter end will prove little, and if you get ANY difference, then you have a problem, there should be no measurable voltage drop from one end of a battery cable to the other (well there shouldn't be), so... test procedure is, hold positive on STARTER positive, and negative on the motor earth, have someone turn the key to the start position and observe the voltage measurement, make sure all your equipment and body parts are out of the way of course!!!