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TR6 Quick TR6 gear reduction starter wiring help

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sammyb

Luke Skywalker
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Still getting the CLICK from the starter relay on the 74 OD TR6 with nothing else happening. Pulled the brand-new-looking gear reduction starter and tested the wires. I have 12V coming from the red/white relay all the way to the wire at the starter when the key is turned and 12V constant from the battery to the big post.

This is how it was wired: Red cable from battery on the big terminal. Red/white from relay on the small screw terminal on the opposite side of the starter. Nothing plugged into the little covered spade connector next to the big positive battery terminal. (Is ground supposed to be there?) Now I can't remember if there was a wire running from the front to the back, but I'll check when I run back up to my garage.

Am I missing something? It has been about seven years since I last wired a gear reduction starter -- and that was to a TR3 with an external solenoid.

Thanks for the help guys.
 
A photo might help. On both of my gear reduction starters, the solenoid terminal is a 1/4" quick connect inside a plastic shroud. What happens if you apply 12v to your 'unused' terminal?

FWIW, I just had my old TR3 gear reduction starter apart the other day. One of the contacts inside the solenoid was shaped slightly off, so the contactor (moving ring on the plunger) was only catching the edge of the contact. Not sure if that was the problem or not, but I cleaned up the contacts and modified the one for better coverage. Haven't had "click-nothing" since.
 
StarterWiring.jpg

I found this photo online to make things quicker. The small quick disconnect there that the arrow is pointing to is not hooked up to anything on mine. I tried clipping the white/red there and nothing happened.
 
Bobby D's pic?
\Couple of things
Check the starter relay that you are getting current to and fro
Make sure that seatbelt mod is bypassed
 
I just totally removed the starter and brought it home. Here are photos.
The red/white was connected to the small screw terminal in between the thick wire in the first pic IMG_0693.jpgIMG_0694.jpg and the battery positive was connected to the big post/nut in the second. Putting power to the small quick-disconnect causes all kinds of nice sparks.
 
The seatbelt thing is bypassed. And again, the relay is sending 12V through the red/white wire (which I assume it wouldn't if the seatbelt thing wasn't bypassed). I have a wiring diagram for the whole car, but not the high torque starter. I don't see a true external solenoid, just the relay. I wonder if the starter is hosed?

I wish I had something that told me which things had to be positive and which to ground so I could just bench test this bastage.
 
Don't think there is a ground
Think the shell is the ground
Thought you pulled it and tested it
 
As noted, the case will be the ground. What looks like the aluminum main case is actually the solenoid; the motor proper is the round yellow and gray steel thing thing hanging off to the side.

To test the motor itself, you can pry up that squareish rubber boot and apply power. That will bypass the solenoid contacts. But you'll need a stout power supply (eg a car battery) and good stout connections (eg jumper cables). I tried it with a small AGM battery (from a computer UPS) and it didn't have enough oomph. Be sure to have the starter held securely too, it's going to want to jump around from the torque reaction of spinning up the motor.

It should be safe to remove the three screws that hold the 5 sided cover in place. Then you can lift out the solenoid plunger and return spring, to inspect the contacts. I'm fairly sure that will also make it clear which terminal is for the solenoid, which I suspect is the one inside the black plastic shroud.

I'm going to guess that the terminal with the screw has a contact inside, so it only gets power when the solenoid is pulled in. On some TR6, that would get a white/yellow wire that shorts out the ballast resistor while the engine is being cranked (to provide more current to the coil for easier starting). However according to Dan's diagram, your 74 uses a relay for that function, so the terminal is unused.

Another way to test would be a powered test lamp or ohmmeter. The solenoid terminal should show continuity (and nearly zero ohms) to the case; while the output to the coil should be open circuit (when the solenoid is not energized).

The solenoid draws a big wad of current initially and has a lot of inductance, so the shower of sparks may just indicate that you didn't get a good solid connection to it. I didn't try to measure the pull-in current, but the holding current was around 12 amps and I'm guessing that pull-in was several times that much.
 
Thanks Randall, I'm going to test it per your instructions and see what blows up/works ;)
 
Hooked the starter up as directed to my battery charger. I toggled it up and it started spinning at 15 amps, so it works.

I'm guessing that I need to try hooking it back up to the car with a solid connection to the white/red wire at that quick disconnect. It's possible that when I put it in to test, the wire wasn't hooked securely.
 
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