TR2/3/3A Remote starter to alternator connection....

[karls59tr]

Does the heavy black cable from the Alternator go to the top or bottom connection on the Solenoid?

 

[martx-5]

I'm assuming you have an alternator installed in your TR3 and I'm assuming the heavy black cable comes from the output terminal of the alternator. If so, it goes on whatever post you have the battery cable attached to, NOT to the one going to the starter.

 

[TR3driver]

I'm assuming you have an alternator installed in your TR3 and I'm assuming the heavy black cable comes from the output terminal of the alternator. If so, it goes on whatever post you have the battery cable attached to, NOT to the one going to the starter.

Which would normally be the top post; unless of course your car has been modified

 

[karls59tr]

Just wondered if I had the hookup wrong.The reason I asked is that since I installed a new wiring harness I have had issues with a""new" battery going dead after a few days! I recently installed a replacement alternator to complicate things. Electrical is not my strong point. What's the best way to track down what's draining the battery???

 

[TR3driver]

What's the best way to track down what's draining the battery???

"A few days" says the current drain is fairly small, so I would start by doing some checking with a DMM that includes a 10 or 20 amp scale. The procedure varies with the meter, but usually there is a special plug that is only used for the high current scale. Don't forget to move the lead back when you are done! (The high current input is basically a calibrated short to ground, so unpleasant things happen if you forget and try to check voltage with the lead in the current plug.)

To check current, you need to break the circuit and insert the meter (so the circuit closes through the meter). For example, to check that the alternator output is not the problem, you could pull that heavy black wire off the solenoid post, connect one meter lead to the black wire and the other lead to the solenoid post. With a digital meter you don't need to worry about polarity.

Another approach, simpler but much slower, is to try disconnecting portions of the car and wait to see if the battery still runs down. Although not common, it is possible to have things that only draw current some times, so this may be the only way to find the problem.

Just for example, I once had a non-LBC that would run the battery down overnight, but only sometimes. More by luck than anything, I finally realized that the relay for the rear window defogger grid had gotten contaminated with salt. On evenings when dew was forming, the combined moisture and salt would leak enough current to operate the relay coil and power up the grid! Never would have found that if I hadn't happened to walk by the car one night and see the indicator light on.

 

[karls59tr]

So it turns out that I my " hidden anti-theft electrical fuel pump switch" was wired direct to the solenoid. D'oh! ...so the fuel pump was running all the time in the garage till it ran the battery down. I'm only running one horn(big loud Mercedes horn) so I was thinking of running the pump switch to A2 on the fuse unit.
Car starts and runs OK but the Amp needle stays in the center position.....isn't it supposed to swing to the + side when the battery is charging?.... or since I charged the battery over night and it has a full charge then the needle wouldn't swing to the + side to show it's charging? I'm used to seeing the Amp gauge needle bouncing but with a new harness maybe it wont. Any thoughts?

 

[Geo Hahn]

For an electric fuel pump I would be looking for a white wire circuit (adding an inline fuse) or a green wire circuit.

I know even less about alternators than I do about electric fuel pumps but the connection you described (big cable from alternator to battery post on solenoid) would seem to have the alternator charging the battery w/o the ammeter being in series - thus no needle movement when charging.

 

[TR3driver]

Yup. With it connected to the solenoid like that, your ammeter will only ever read discharge (or zero), even when the alternator is carrying the load and/or charging the battery.

I don't recall which fuse terminal is which offhand, but the horn fuse is also hot all the time. You'll want to tap into the other one. (Which are the white and green circuits that Geo mentioned. White is unfused directly from the ignition switch, green is the load side of the fuse.)

 

[karls59tr]

So the black heavy cable from the alternator goes to the POS battery post. Correct? I have switched the car to NEG ground. Thanks for the input guys.

 

[GTP1960]

Fwiw:
re: your electric fuel pump.
you may want to consider an impact switch or at least a "engine off automatic kill switch".
(my auto kill switch is wired to the coil, it will only run for a few seconds if the engine is not running)
i also have it wired thru a relay, and fused.

 

[karls59tr]

Yup. With it connected to the solenoid like that, your ammeter will only ever read discharge (or zero), even when the alternator is carrying the load and/or charging the battery.

I don't recall which fuse terminal is which offhand, but the horn fuse is also hot all the time. You'll want to tap into the other one. (Which are the white and green circuits that Geo mentioned. White is unfused directly from the ignition switch, green is the load side of the fuse.)

I checked with Triumph Rescue and they say the the black cable runs from the lug on the back of the alternator to the starter solenoid and attached to the same side as the battery cable! Do I need a Voltmeter?