512 TR alternator problems

starter motors are a problem on TRs

you may have an electric leak, check the switch behind where you put the ignition key, mine was on all the time & eventually killed the battery

 

12.1V Battery voltage with the engine not running is fine however the battery voltage of 12.5V with the engine running is poor, ideally you need over 14.0V volts as a minimum. I suspect your regulator is faulty, not sure what make of alternator are on yours but they are a fairly straight forward replacement but usally you need to remove the alternator from the engine bay to do so.

To test if you belts are slipping, using you mulitmeter across your battery posts check the voltage, then turn on all the lights and the air con, if the battery voltage drops the belt is slipping under load, if the voltage stays the same the belt tension is ok, but the easiest test is to check the belt deflection by hand, it should be firm to push and pull on, ideally you would only want about 10mm~15mm deflection either way push or pull on the belt otherwise your loading up the bearing and will encounter future problems

 

Last time my battery light went on (in my '89 Mondial t with the Delco alternator), my alternator was about to take a crap on me; and I was left stranded on the road shortly thereafter.

My battery was just fine as well, but my alternator was not giving the battery the proper charge to run the car.

I see that your 512tr is a 1992 model. If it was produced before June, 1992, then from the factory it came with the Delco, and not the improved Nippondenso, alternator (unless the upgrade has already been done). Sorry if I am giving you information you already know...

 

Double check the connections to the alternator. make sure you have 12v at the main power connection of the alternator (the one big wire) if all is ok, sounds like time for a new alternator.

You can access the alternator by removing the front coverings in fornt of the altewrnator ( four 10mm bolts underneath one on each end and two staggered in the center).

best regrads, Jim

 

He has the Delco, at least according to my conversation with him and pictures sent.
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But are you sure you have the older alternator?

 

Can be done, must change the mountiing bracket and will have to change the one electrical connector for the back of the alternator I believe the delco is a two wire and the Nippondenso is a three wire. If it is the same as the Mondial and 348, the third wire is a keyed power. Daniels pic shows the difference.

Toughest part will be finding the connector.

best regards, Jim

 

I had the same problem just come up in a '91 TR. I spoke to my tech and he said to pull the two connectors underneath the coolant tank and check to see if they were green. He said to clean them with contact cleaner and to see if the problem persists. Then to call him. I did as he said, and no more flashing warning light. It did the trick.

Easy fix. Good luck.

Alex

 

Another parts store expert strikes again.

 

Just a thought, Have you run the engine above idle to test? It might take a few rpms before the alternator "kicks in" and begins to charge. Otherwise it's the dreaded "something else" which could include (stay with me here!) the alternator is STILL bad.

Check all those connections (corroded wiring that still looks okay) fuses, junction blocks, etc. The charging system is really pretty simple (but not everything is easy to see).

 

Last year someone had a bad harness that the dealer found after 4 or 5 new alternators. I have a schematic for a 91 tr (just learned they used motronic 2.7). Looks like there is a large cable to the starter which then goes to the battery through a connector (which could have some corrosion so that high current for starting will pass but low current for starting the charging might not. Also, there is about three (or four) connectors that pass voltage up to the chargeing lamp in the dash. The connector close to the alternator also has the wire to the starter solenoid so it is probabbly in the engine compartment. So just work your way forward. Usually the guys that rebuild stuff check it when done and these units (at least my 86) are gm/delco so pretty common guts (mounting tangs different). FWIW, my 348 battery connector between the battery and strarter had a white oxide on the mating surface that your car might also have. It kinda looks like the car is powered from the battery, then to the engine and the starting/charging is from the large battery cable to the starter. The schematic is 16x24 that I could copy and mail (PM me). Good luck.

Jeff Pintler
89 348tb, 86tr

 

Just a hunch, look at the fusebox and unplug the connectors and inspect for burnt connectors.

regards, Jim

 

Looks to me like you are getting WARM so to speak. Not sure what the connector is for. Keep looking, this might be just the beginning.

 

I suggest to repair the connection. You probably can reuse the connector but you may have to replace the pins in the connector. Remove the pins and see if you can clean and tighten them up.

If they cannot be repaired, you local dealer can lookup the connector and pin and order what you need.

I see the number of pins but cannot see the wire colors. give me the wire colors and I will see if I can find out what it is for.

best regards, jim