Do I have defective starter?

[mikec03]

My starter on 95 subaru would occasionally not turn over.  So I took the wire to the starter solenoid wire and used it to pull in a relay which I mounted on the fire wall.  And then ran a wire directly from the battery, though the relay to the starter solenoid.  The use of a relay in this situation is a fairly common correction which has been mentioned many times on this forum.

 

Unfortunately, now the wire from the battery to the started solenoid is occasionally blowing a 20 amp fuse that I wired in!  I can't find what the amp rating for the starter solenoid is, but it must be less then 20 amps?

 

So is the starter defective?

[1-3-2-4]

Does it just make a click sound when you try yo start? If so it's the contacts in the starter, it's like $4 worth of parts, what happen is inside the starter is a plunger that moves back and hits those copper contacts, when they wear it no longer makes contact.

 

I replaced mine in like 20 min.

[mikec03]

Yea, I figured that the solenoid isn't operating up to its original capacity.  However, I also see that the OEM wire that energizes the solenoid appears to be 10 g or thicker.  Ten gage implies an amp load that the subaru engineers figured would be near or above 20 amps at the worst conditions [based on 5% voltage lose over 6 ft]

 

So, I put in a 30 amp fuse and I will see if it works.  I'm not enthusiastic about taking out the alternator at 10 degF.

[presslab]

I have measured two 4EAT starters, a gear reduction one and one non-reduction, and they both took about 11 amps.  The voltage drop on that circuit is critical, a bit too much and the solenoid won't engage (that's the reason for the added on relay).

[mikec03]

Yes, I kind of thought that the amp load should be less then 20.  I put in a 30 amp fuse and it started OK this morning at 10 degF.  There might be something wrong with the solenoid.  Maybe it shorts at random times?  I understand the reason for the separate relay.  I guess I will drive it and see if the relay fuse fails again.  This is really a bad time in Wisconsin to have starter problems.

[Rooster2]

Yes, I kind of thought that the amp load should be less then 20.  I put in a 30 amp fuse and it started OK this morning at 10 degF.  There might be something wrong with the solenoid.  Maybe it shorts at random times?  I understand the reason for the separate relay.  I guess I will drive it and see if the relay fuse fails again.  This is really a bad time in Wisconsin to have starter problems.

Yea, never fun working on a car, when it is winter cold, really necessary to work in a heated garage. If you think there could be additional issues with the starter, then I would suggest a new, or rebuilt starter. Otherwise, repairing a bad starter with multiple issues can be extra time consuming, and really frustrating.

[presslab]

Yeah a random short would be my guess too.  It wouldn't hurt to put an ammeter on it, just to see how close to 20 amps it is.

[Fairtax4me]

Power for the starter solenoid comes from SBF 4 which is 45 amps.

The same fuse delivers power to several circuits when the ignition switch is in the "On" position.

 

I wouldn't worry about it too much. Starter solenoids have two separate coils with a very strong magnetic field to hold the plunger in tight contact with the electrical contacts in the solenloid, as well as to hold the bendix gear in position while it is engaged with the flywheel.