TR6 TR6 no start after running amazingly well til now.

[gbtr6]

Hi, hoping I can get some help here. Saturday took my six to a guys house for a shop tour and get together. There were six perfect big Healeys there, my six, an XKE, and an MGB. When it was time to go, everyone got in and started and drove off. Except me. Up til now, I had the best running 6 there was. Only needing to replace front shocks.

The guy whose shop we were at has a son that is an electrical engineer. He got out his tester and we tried to find the issue. My electric fan is set to come on at the first turn of the key, but it didn't come on either. I suspected the relay as I had some issues before when the starter would engage on the first turn of the key, not fully turning it to start. I replaced it and all was well. So, we resorted to rapping on the relay when I was cranking the engine. It would catch only when I released the key. It would start, and the fan was running too. He followed me home, and it ran fine.

The only issues I had were no turn signals, and weak brake lights. Also my gauges were intermittent. My voltage also stayed at 11 volts when it usually is 13.

Would a bad alternated cause any of this? I had a spare relay and swapped it. No joy. Had my wife rap on that on and the original one. No joy either. I am going to take the alternator to get tested.

Any suggestions? Also, when the key is off, what should the terminals on the relay read, and when cranking, what terminals are hot and what should they read. Still have some summer left and I want to enjoy it in the Six.

Thanks,
Perry

 

[glcaines]

The first thing I would do is charge your battery. You mentioned that it would fire and start when the key was returned to the run position, but not in the start position. Your coil is fed by two different circuits. In the run position, the voltage to the coil originates at the ignition switch and is fed to the coil by a resistor wire. Normally this wire is cloth covered and is a solid wire, not stranded, which can help identify it. The other source of power to the coil comes from the starter. There is a white wire that runs from the starter solenoid to the coil. I believe it is a white wire. This wire only feeds 12 volts when the starter is energized. If your engine won't fire in the start position, this circuit may be faulty. Easy enough to test with a meter. I would recommend checking the output of your alternator with a meter. For a 12 volt system, the alternator output must be at least 13 volts to charge a 12 volt battery, and preferably around 13.5 - 14.2.

Do you have electronic ignition? Electronic ignition requires good voltage from the battery. If the battery is weak and the voltage drops, even slightly, the electronic ignition module can malfunction. If your alternator is indeed faulty, resulting in a somewhat discharged battery, this could cause an electronic ignition system to malfunction.

 

[gbtr6]

Thanks for the reply. I do have Pertronix ignition. Thing is, once it was running, it ran great. No stumbles or anything. I do suspect the coil, and the low voltage circuit. I took the alternator to Advance and they said it was bad. I have the original Lucas and it has the pigtail and the separate wire too. I'm tempted to hook it back up and run the car, if I can get it started to test it. Where would I take my readings from, what terminals on the alternator? May have to get a replacement. I'll check the battery too.

Thanks,
perry

 

[glcaines]

It is very easy to check your alternator if you have a simple multimeter. Set the meter to read DC voltage on an appropriate scale - likely 20V. Start the car. Place the positive probe from the meter on the main output terminal of the alternator. Place the negative probe someplace on the engine block where you get a good connection. You should be reading at least 13 volts and preferably near 14 volts. If there is no reading the alternator is bad or you have a poor connection. If the reading is low, increase the idle speed up to around 1000 RPM and see what the reading is. If the output goes up to acceptable levels, your alternator is OK. You can also alternatively place the positive and negative meter probes directly on the pos and neg posts of the battery. However, testing directly at the battery doesn't eliminate a connection problem if you don't have any output, but if you do have good output measured directly on the battery, your alternator is good.

 

[dklawson]

To add to the above, the wire from the solenoid to the coil (+) terminal should be white/yellow. It is a bypass to provide a ballast coil with more energy/power to create a hotter spark for engine starting. As stated above, it is only "hot" when you are cranking the engine over on the starter.

If your car has a ballast ignition coil AND Pertronix, the wiring is not as simple as red wire to coil (+), black wire to coil (-). The Pertronix needs a full, clean 12V supply to run properly. Therefore, if you have a ballast ignition system, the Pertronix red wire is typically routed directly to the fuse box and connected to a switched terminal there. The black wire is left on coil (-).

Others have advised you about the battery and how to check the alternator output so I won't add anything there except to suggest if you have any doubts, remove the alternator and take it to a local parts store. They will typically bench test them for free.

 

[Deleted member 8987]

WY (white/yellow?) wire from C4 on the solenoid feeds the coil for start bypass. Since the car cranks, ignition switch appears to work. Voltage at the power in to the coil is important to know. If zero cranking, check that WY wire on C4 at the solenoid. If nothing there, most likely needs a solenoid.

Battery...I don't know. If it cranks at normal speed with the full load of the starter motor, not a battery. If it has enough power to make it run when you let off the key and the solenoid drops, we know the coil will fire with the lower voltage on the ballast feeding it.

You can always hot wire it to start, then pull the wire...just be reasonably quick.

 

[dklawson]

WY (white/yellow?) wire from C4 on the solenoid feeds the coil for start bypass. Since the car cranks, ignition switch appears to work. Voltage at the power in to the coil is important to know. If zero cranking, check that WY wire on C4 at the solenoid. If nothing there, most likely needs a solenoid.

If there is nothing on coil (+) when cranking, you may have issues with the solenoid or the white/yellow wire. Zero voltage would definitely indicate a problem with the white/pink wire from the ignition switch to the coil. With the white/yellow completely removed you should still see some voltage on coil (+) when cranking. It could be anywhere from say... 6V to 10V.

If the battery is tired and the ballast bypass (from the solenoid) is not working, there may be insufficient voltage to power the Pertronix module when you turn the engine over on the starter.

 

[Deleted member 8987]

If there is nothing on coil (+) when cranking, you may have issues with the solenoid or the white/yellow wire. Zero voltage would definitely indicate a problem with the white/pink wire from the ignition switch to the coil. With the white/yellow completely removed you should still see some voltage on coil (+) when cranking. It could be anywhere from say... 6V to 10V.

If the battery is tired and the ballast bypass (from the solenoid) is not working, there may be insufficient voltage to power the Pertronix module when you turn the engine over on the starter.

Well, the first part is what I said. But, when cranking, the ballast is OUT of the circuit, and if it does start when he lets go the key, the ballast is, in fact, working.
It has to be, otherwise you would backfeed load through the ballast and it would probably last in the milliseconds before smoking, depending on what is on.

 

[dklawson]

But, when cranking, the ballast is OUT of the circuit, and if it does start when he lets go the key, the ballast is, in fact, working.
It has to be, otherwise you would backfeed load through the ballast and it would probably last in the milliseconds before smoking, depending on what is on.

Yes, you are correct, if the engine tries to fire when the key is released then the resistor wire (ballast) is working. Starting on release of the key is symptomatic of a discharged battery and a fault in the bypass wire (white/yellow wire) or its solenoid connection.

However, the ballast resistance is not removed from the circuit when you turn the ignition key to the start position. You can observe this by disconnecting the white/yellow wire from coil (+) and cranking the engine on the starter. You will find voltage on coil (+) but it will be less than 12V due to the current draw of the starter motor and the fact that current to the coil has to flow through the ballast resistor.

When the white/yellow wire and solenoid are functioning and when the ballast resistor is intact and functioning, there is no voltage potential across the ballast resistor when the key is held in the start position. One side of the ballast resistor is at battery voltage from the ignition switch, the other side of the resistor is at battery voltage coming from the solenoid. With both sides of the resistor at the same potential there is no current flow through the ballast. There is no backflow of current.

 

[gbtr6]

Thanks for the reply. I do have Pertronix ignition. Thing is, once it was running, it ran great. No stumbles or anything. I do suspect the coil, and the low voltage circuit. I took the alternator to Advance and they said it was bad. I have the original Lucas and it has the pigtail and the separate wire too. I'm tempted to hook it back up and run the car, if I can get it started to test it. Where would I take my readings from, what terminals on the alternator? May have to get a replacement. I'll check the battery too.

I checked the battery and it says 12.5 volts. Put the alternator back on and also hooked up the relay I took the cover off. Turned the key, still no start. I turned the key to on, pushed down on the contacts and it starts, and runs but the starter doesn't disengage. I turned it off, then turned just the key, and watched the relay. It doesn't seem that the relay moves to make contact. I assume the coil should be excited, the contacts would touch, the car would start and the contacts would break, and the car would continue running. Is that the sequence? If so, I have something not allowing the coil in the relay to function properly, and break the contacts.

Thanks,
Perry

 

[dklawson]

For now, focus on starting, not charging. Charge the battery overnight with a battery charger set to 2 Amps, then try starting the engine the next day.

If you don't have a wiring diagram for your car, use the one on the Advance Auto Wire website (link below).

Advance Auto Wire TR6 Wiring Diagram

The '74 TR6 diagram (top left corner of page 7) shows your car will have a starter relay. Presumably that is the relay you are referring to. That relay is in turn fed by the seatbelt module (bottom center of the diagram). I have never worked with those so I can offer no advice. Hopefully others can tell you how to troubleshoot the module.

If no one offers guidance on the seat belt module after a few days it will be worth discussing ways to bypass/replace it so you can get the engine started without the factory relay. Original wiring is best so I'd like to wait until others have a chance to reply. While waiting for people to chime in you may want to check the seat switches and seatbelt latch switches. If they are not working correctly there is a good chance the seatbelt module is not letting the relay close.

 

[poolboy]

Sooner or later on 74 cars the white/red wire and the white/orange wire in the seatbelt buzzer's 12 pin plug need to be connected in order to make the starter work with the ignition key....The factory made that splice in the 75 cars.

 

[gbtr6]

On the seat belt module, do you jumper the two wires AND plug the pigtail back into the module? A long time ago, when the module worked and buzzed, I stupidly perhaps took a screwdriver to the silver buzzer and disabled it. All wiring still intact. It makes sense that this may be an issue as I recall in the past, I had to pull the pigtail and put it back in partially till it worked. It may have shaken loose from the front shocks being weak and the shimmy she has.

I assume I'd be able to see the contacts on the relay I have bared naked, move to make contact. Or would they move too quickly to see? Hope the fix you suggest works. I've heard it before, but never had a problem.

Still may have a bum alternator, but hope to get it running first.

Thanks,
Perry

 

[poolboy]

I responded in detail on the Triumph Experience....but the short answer is "No, I didn't."

 

[Gliderman8]

Pool boy is spot on. I had similar problems in my TR6 until I installed a jumper wire connecting the WO/WR wires.
The pic shows the SOLDERED side of the interlock board. I simply soldered a wire connecting the two contacts (pins 11 & 12) at the 8/9 o'clock position in the photo.

 

[gbtr6]

Success! I jumpered the wires on the seatbelt pigtail and it started and ran. Well, it still gave me a hard time with the relay I had wired in. I had another, that I had been using, that I put back in and it worked fine. It stalled a couple of times coming out of the garage, with the ignition light coming on. It never does that. I took it for a spin and it ran great again, but never gave more than 12 volts, just, on the volt meter. So, it's a qualified success. I need an alternator.

Now, a question on alternators. Advance has one for @ $60. Not sure if it's a direct plug in, but I assume. I heard some do not have that feedback wire terminal. Any comments?

Thanks for all the help, I appreciate it

Perry

 

[dklawson]

The Advance Auto Wire schematic (link in post #7 above) shows the '74 had the 3-wire alternator. If your locally sourced alternator is the right size/shape and accepts the same 3-wire plug, you are all set. However, before leaving the parts store make sure the rebuilt unit comes with the pulley and fan (some don't). Better yet, call the store and ask before you go.

If you have to remove and re-use your existing fan and pulley, I have found the easiest way to remove the old parts is to hold the alternator fan with a heavy towel and use an air impact wrench on the nut. Gentler methods typically result in a damaged fan.