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TR4/4A High Torque Starter Wiring

bammons

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Well I did it again. I bought and installed my new high torque starter over a year ago and am starting to wire the car back. But now I cannot find the instructions so I know what to do with the wire lead that attaches to the push terminal on the side. I did search and still a little confused because some seem to be doing different things with that wire (and solenoid). It appears from some of what I have seen that this short wire simply plugs in and then attaches to the post where the heavy wire attaches at the top. Is that correct? If I do that then I simply attach the battery cable and the heavy lead from the starter on the same terminal on the original starter solenoid. Is that correct? Anything else? Is this the best way? Bruce
 

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Kinda hard to answer without even knowing the make of the starter. Have you tried looking on line? Often you can download the instructions in PDF format from the manufacturer's web site.

You really don't want to do this by guessing or trying things randomly. You're dealing with a lot of electrical power.

That said, the starter on my Porsche, one of the more common makes, has an internal solenoid. There is a large connection for the heavy cable from the battery and a smaller one for the wire to the start position of the ignition switch. No external solenoid is used. Yours may be the same. Or not.
 
Steve - BPNW only shows the manufacturer as GSM. In searching this does not pull up anything and BPNW does not have instructions on their site. Looked at Moss and they sometimes have attachments to products like this but they do not. I believe it looks like a British Starters unit. Their site says to attach the jumper cable from the push in connection to the main terminal on the starter. Doing so bypasses the internal solenoid of the starter and that 99% of customers do that. Why would you wish to bypass the internal solenoid? Would I not just want to connect the starter cable coming from the starter to the same terminal on the old solenoid (assuming I wish to retain the old one for looks) as the cable coming from the battery? I can call BPNW tomorrow and get them to send a copy of the instructions but I also was looking for advice as the the best way to do it. Bruce
 
Probably my earlier speculation was correct. If you connect a wire from the main terminal to the push-on, it will turn on the internal solenoid whenever the main terminal is powered--so, you haven't exactly bypassed it, but the same thing happens. That way, you can use the original solenoid and connect the starter as you did the original one. I guess people like to do that, maybe because it's simple and you can use that convenient pushbutton on the original solenoid to turn over the engine when you're working on it. As for me, I think I would prefer to use the starter's internal solenoid.

If it were me, I would first try connecting a heavy cable from the battery to the starter; disconnect the battery and put the car in neutral, of course, while doing that. Then, reconnect the battery, and if all is well (i.e., nothing happens), connect a lighter wire from the push-on terminal and touch it to the battery (keep your fingers clear, as it will probably create a spark). The starter should then run. If it does, disconnect the battery again and make the connection to the ignition switch. Easiest way is to splice it to the wire that actuates the original solenoid (1/4" push-on terminal on its side).

The connection to the TR4's electrical system is made at the solenoid (fairly heavy brown wire), so if you remove the original solenoid, that has to be reconnected to the battery some way.

I really think this will work. Just be careful, keep the transmission in neutral, and disconnect the battery while making changes. If something gets hot or makes big sparks, stop right there.
 
Well my car is going back together so no battery yet and the rest of the wiring is being connected. I also just finished bypassing the voltage regulator because I put on the look-alike altenator. I am not proficient in deep electrical theory (or much of anything else) so I think maybe I should by-pass the built-in solenoid (use the jumper wire provided) and use the original as originally wired. I did find a thread on a AH forum I think that said more current would go through the starter switch if I used the built-in solenoid. That doesn't sound good for our cars. I can revisit this later after I get the car running. Bruce
 
This is how I wired my High Torque starter.
Starter wiring.jpg


David
 
David - Thanks for the drawing. Now it is just for me to decide whether to bypass the brand new solenoid on the starter or do what you did which bypasses the original solenoid. So I do not know if it makes a difference in performance or reliability to do it one way or another. Does using the "new" built-in solenoid make the starter work better? How reliable are our original solenoids? Bruce
 
Well my car is going back together so no battery yet and the rest of the wiring is being connected. I also just finished bypassing the voltage regulator because I put on the look-alike altenator. I am not proficient in deep electrical theory (or much of anything else) so I think maybe I should by-pass the built-in solenoid (use the jumper wire provided) and use the original as originally wired. I did find a thread on a AH forum I think that said more current would go through the starter switch if I used the built-in solenoid. That doesn't sound good for our cars. I can revisit this later after I get the car running. Bruce
I think that's a prudent way to go. It will involve minimal change to what you have and, as you say, you can change things later if you wish.

David's setup will certainly work, but the original solenoid isn't really adding much. It does retain the ability to push a button and crank the engine from inside the engine compartment--occasionally helpful when you're working on the car. The starter button could be wired directly to the starter motor, then the solenoid could be removed entirely.
 
Also gives the appearance of originality if that matters to you.
My goal was to have the push button under the bonnet. Makes fault finding easier if you can bump the engine or start it using a hot wire.

David
 
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