Installed High Torque Mini Starter ... Battery Draining

[BGBronco]

I just installed the Toms High Torque Mini Starter and the battery is draining. I did install Hydroboost at the same time but I cant think of a reason that would have a big impact on the battery. Any thoughts on what could be causing the drain? Battery was new in 6/21. Thank you.

 

[73azbronco]

I'd disconnect starter and check drain.

 

[BGBronco]

The one thing I have noticed is that the started seems to continue to try to star a second or two longer than neccessary

 

[DirtDonk]

Are you still using the fender mounted starter relay? Or did you wire the key directly to the new starter and solenoid?

 

[DirtDonk]

If you have a previous thread on the install, are you going to update that with your issue as well?

 

[SLOWnEASY]

Do you have a 12v test light? If so disconnect the positive cable at the starter and put the test light in series between the cable and the starter post. If the light lights you have a draw. You can also do the same thing with a digital multimeter. But they seem to all have expensive internal 10 amp fuses that can get blown if there is too much current draw. So I prefer a test light.

 

[BGBronco]

Are you still using the fender mounted starter relay? Or did you wire the key directly to the new starter and solenoid?

Sorry to be vague but everything is wired back here. I basically did a remove and replace job.

 

[DirtDonk]

Interesting. Here is what I think I see.

One large newer red cable, looks to be at least 4-gauge, or possibly 2, on one side of the relay, presumably from the battery?
On the same stud, a red wire, probably 10-gauge, presumably from a new harness going to the fuse panel?
And perhaps a third, older wire, possibly 6-gauge, going where?

And on the other stud, I see just one black cable, presumably going to the starter?
I can see a second ring. Is that possibly a split washer, or is it another wire lug?

Is all that correct?

 

[SLOWnEASY]

Well with that setup the starter is definitely not the power draw. I also doubt your hydroboost is a problem unless you accidentally pinched a power wire under the mounting hardware (no I don't think you actually did that) So now you need to figure out if the that fender mounted relay went bad or if the issue is somewhere else. Is the thick red battery wire the only positive wire on the positive battery post?

 

[ssray]

The one thing I have noticed is that the started seems to continue to try to star a second or two longer than neccessary

Sounds like the starter bendix is hanging up a bit. It could just be stiff or a little off in manufacture. Some starters can be shimmed if the teeth are meshed to tight but they’re a block mounted style. If there’s any play in the mounting with the bolts a bit loose, you could try prying the starter away from the ring gear while tightening the bolts and see if it helps at all.

On the electrical side, don’t know if you’re using a points/coil system but that link to the starter relay that applies full 12v to the coil during cranking could drain the battery if accidentally connected to the hot side somewhere. I can’t really envision that but just thought Id mention it.

 

[SLOWnEASY]

Another though based on you saying it seems that the starter seems to continue to crank after you let go of the key. Maybe try disconnecting the S terminal from the fender mounted relay. Then hold the wire to the S terminal by hand or use an alligator clip wire. Pull the coil wire from the center of the distributor cap so the engine won't start. Then have someone crank the engine over. While it's cranking disconnect the S terminal and see if the cranking continues or immediately stops. If it continues then the fender mounted relay is going bad.

 

[DirtDonk]

And even though the battery is “only” four or five years old at this point, it’s always possible that it’s going bad.
If so, that would be filed under one of our “coincidental failure” models.

A quick test though is to make sure the battery is charged, then disconnect it overnight. If it’s still draining in the same timeframe as before, it’s simply the battery going bad.
If disconnecting the battery cures the problem, then you’ve proven that there is in fact, a drain connected to it.

 

[Shimmy]

dont the high torque starters require swapping the wires vs OEM? i recall switching a couple wires around, but dont recall.

 

[DirtDonk]

Yes. They can be run either way, but if not swapped around, they can have a “starter run on“ situation more often than not.
That’s why I was asking about the orientation of the wires visible on the starter relay.

 

[BGBronco]

Appreciate all the information. I will be going through this on 'Christmas eve' morning. Thank you!

 

[Chiclassics]

And you checked your battery is getting charged to 13-14V when car is running? it can also be coincidental with the starter change ill start there and then do battery test overnight (disconnected) Paul suggested to rule out bad battery before further tests

 

[BGBronco]

Guys - It was the battery. What are the chances that something unrelated goes wrong after replacing at part? 90+% if it's older vehicle! Thank you for all the input!

 

[SLOWnEASY]

Hate to say it but I find the chance of something else going wrong is about an 40 percent chance. At least that's been my experience.
Glad you got it all sorted out and it was a simple as a battery swap.

 

[Chiclassics]

Guys - It was the battery.

Bingo.

 

[Broncobowsher]

As for the starter staying engaged for a second or two at startup. It is how it is wired. The quick and dirty (and hack easy) is to put a jumper to the solenoid on the starter to the switched battery feed cable. The correct way is to move the battery feed cable to the battery side of the solenoid so it is always hot. Extend the little jumper that the starter probably came with and put that one the fender solenoid where the starter cable once was.

What is happening...
The new starter with the fancy permanent magnet motor is also a pretty decent generator. When the engine starts and you release the key, the original fender starter solenoid disconnects power to the starter. The starter has momentum and has to spin down. As it is spinning down it is generating enough power to keep the starter mounted solenoid energized. Not from the key, not from the battery, but from the starter acting as a generator. So long as the sprag releases, engine power is not put into the starter and it will release as soon as the starter spins down slow enough to not generate enough pull in power on the solenoid.
By doing the rewire described above the fender solenoid shuts off power to the starter solenoid. The power as the starter spins down doesn't go anywhere, and not into keeping the starter mounted solenoid pulled in. This is factory Ford wiring in the 90s when factory mini starters were first used. Ford did this to make the new starters work with the old wiring infrastructure.