Switched the starter, still not starting

[Burning Pyro]

Ok my supra has been out for a few months due to starting failure. I pulled the starter and put a new one in there.

prior to this the car would sometimes start and sometimes not. i could put it in gear at times and start, sometimes crank it 4 times and then it would go and if it died i would have to wait maybe 5 minutes to get her going again.

now when i go to start it just clicks. just one click like the battery is dead. checked the two wires on the starter and they are on alright. Maybe im overlooking something, if anyone has anything please let me know. Thanks

[toneloc87 2]

ya i have the same prob so help would be sweet

[robertsws]

the only other thing i can think of is your battery. a battery can register good volts but it is the cranking amps that get it to start. the only way to check that is a battery tester. the only time i've ever seen one is when i worked at a dealership but i'm sure they are around. especially at a garage.

[1985 supra MK2]

Here is what i would suggest, replace the positive cable that goes to the starter, disconnect the negative cable from the body and clean the stud or the firewall where it connects and use a wire wheel and clean the area and then re connect it, and if all else fails go through and check the started selinoid, clean the connection of the positive cable and the starter, and if that fails get a marine or RV deep cycle battery and that should work.


good luck with your car.

[CyFi6]

This is an extremely common problem in these cars. The signal wire going to the starter gets old and starts to have resistance, not allowing full power to go to the starter trigger solenoid, therefore it can pull the solenoid so far, but not far enough to get the contacts to touch for the starter to turn. That is why you hear a single click. It is an easy fix, you just have to wire a relay into it. Wire it as such using a wire as big or bigger than the original blue trigger wire. Use these crimp on connectors, they slide strait onto the relay spades and the starter spade. With this circuit, you can use the weak blue signal to trigger full battery voltage to the starter.
RadioShack.com - Cables, Parts & Connectors: Connectors & connectivity: Crimp connectors & terminals: Crimp-On Quick Disconnects (6-Pack)
^ those come with male and female connectors, but you only need the female ones. You will need 4 female connectors so you would have yo buy two packs. Hope this helps you. If you want proof that this will work, hook a jumper wire from the battery positive terminal strait to where the blue trigger wire connects on the starter, and watch it crank everytime.

[1985 supra MK2]

yes i agree that would work but why just use a temp fix when all you need to do is get a new positive cable that runs from the battery to the starter (selenoid) and then that would take care of the problem.? also you might want to have an electrical systems test done on the alternator just to be sure it is functioning the way it is supposed to be.

[CyFi6]

Originally Posted by 1985 supra MK2

yes i agree that would work but why just use a temp fix when all you need to do is get a new positive cable that runs from the battery to the starter (selenoid) and then that would take care of the problem.? also you might want to have an electrical systems test done on the alternator just to be sure it is functioning the way it is supposed to be.

Because that is not the problem. There are two wires that go to the starter; the positive battery cable, which is heavy gauge, and the small, blue trigger wire, that only receives current when the key is turned to start. The problem is the trigger wire, not the big positive cable bolted to it. When you turn the key to start, current goes through this blue wire, energizes a coil of wire making magnetism, and pulls a plunger, when this plunger is fully pulled, it connects two more contacts, the positive batter cable and the bigger coil of wires that turns the starter. The problem is over time that little blue wire gains resistance internally and doesnt provide enough current to pull the plunger all the way to the point where the other contacts touch, therefore you can hear the plunger moving, but its not going enough to make the starter contacts touch. This is why people usually experience this problem more when the car is hot ( heat=more resistance). So by using this relay, you can take the small amount of current supplied by the old blue wire, and use that to switch the relay which in turn will give full battery voltage.

This is not a temp. fix at all. It is permanent. You can take out your entire wiring harness from your car, trace the blue wire back through all its connections and all the other wires its involved with, and replace them all, or you can do a simple relay mod like many many others have done.

[1985 supra MK2]

well i am not trying to argue a point, i had the same problem with my 85 and i replaced the positive cable and it took care of the problem, so like i said i was not trying to argue a point i was just offering advice.

[Bill UK]

Copied from previous post HERE
One of the problems is the gauge of the wire, although probably ok when new, it is too thin and over the years the copper wire deteriorates, resistance increases due to age and the constant heat changes. This becomes more apparent when the engine bay heats up, the thin wire will also heat up, causing high resistance. A permanent fix is to fit a 30 or 40amp 12v relay in the engine compartment. Instructions below.

The thin wire from the ignition activates the coil in the relay which doesn’t need a lot of current. The switching part of the relay takes care of the amps required for the starter solenoid, The large wire going to the starter motor from the battery is the main power to turn over the starter motor once the solenoid is activated, this wire doesn’t need to be upgraded. Insructions;
1. Disconnect the battery
2. Fix the relay to the bulkhead or somewhere covenant.
3. Remove the thin wire going to the starter motor and connect it to terminal # 86 on the new relay
4.Connect terminal # 85 to earth (negative) using a 20 amp wireAt this stage you can check the relay is working by connecting the batteryand switching on the ignition as you would normally do to start the car. You should hear a click from the new relay but the starter will not turn over until you have competed the next steps.
5. Remember to disconnect the battery again
6. Connect a 20 amp wire to the spade terminal on the starter motor. (This is where the thin wire was once connected.) Connect the other end to # 87 on the relay.
7. Connect 20 amp wire straight to the battery and to # 30. connector on the relay. Job Done.

[f00g00]

I agree with the fix as ive had the problem so bad I had to install a remote start switch and used the coinholder for mounting it. After the post by CyFi6 I went ahead and got the relay and put it in in a little over an hour and it works like a champ!!!