[TR] TR6 Electrical Issues

Dave1massey at cs.com Dave1massey at cs.com
Fri Sep 13 11:32:59 MDT 2013

That little round thing with the two wires going to it is the Anti-Run-On 
valve.  It works in concert with the three prong oil pressure switch and a 
special contact on the keyswitch to energize when shutting down.  It applies 
manifold vacuum to the charcoal canisters and hence to the top side of the 
float chambers in the carburetors to starve the engine of gasoline to prevent 
run-on.  It should not be clicking in the situation you describe.  Since you 
have had problems with the keyswitch I would look there first.  If this 
stays energized all the time the engine will start but will not continue to run 
very well.  But it will not prevent it from starting.

If your battery is fully charged but cranks slowly there are a couple 
things to check.  Check the battery ground connection.  On the TR6 the negative 
cable has two tabs, one of which attached to the body at the firewall and the 
other attaches to the engine/bell housing flange.  Make sure that 
connection is solid.  Also check the positive cable connections at both ends.

If you engage the starter with the lights on do they dim?  If they dim then 
you may need a new starter.  If they do not it could be the solenoid.

The next step is to dust off the multimeter.  Measure the voltage between 
the engine block and battery negative when cranking.  It should not exceed .5 
volts.  Measure the voltage from the starter stud and the battery positive 
post.  It should not exceed .5 volts.  Knowing this will help narrow down 
the search.

Good luck.


In a message dated 9/13/2013 10:53:49 AM Central Daylight Time, 
wsb1960tr3a at att.net writes: 
>      My 1974 TR6 has not really be driven since the mid-80's sometime, 
> maybe
> even earlier.I have logged about 15 miles in 1 block test drives over the 
> last
> 5 years.  It just put in a new front clip of the inner left fenderwell and
> front valence and the bodywork is bolted back together. Before this 
> project
> (about three weeks ago) I took the car for a test drive without fenders 
> and
> hood. Now that I want to go for a test drive with the assembled car, the 
> car
> won't start. It started up the first try and then stopped when I 
> discovered
> that it was out of gas. I put in gas and then it cranked briefly and 
> slowly. I
> assumed that it was a dead battery, but the battery had been charged 
> recently.
> I heard what sounded like the starter solenoid clicking.
>      When I hook up
> the battery, something clinks under the hood like it is energized with the 
> key
> off. I checked it out and found that on the right side of the radiator are 
> two
> cylindrical things. The top (big) one has hoses going into it (carbon
> cannister?) and the smaller bottom one has two wires attached to it. The
> bottom one appears to be what is clicking when the battery is hooked up. 
> Can
> someone tell me what this thing is?
>       I previously had problems with the
> ignition key and it wouldn't turn or come out of the ignition. A little 
> WD-40
> and working it and it eventually turned. It is the original key. You have 
> to
> joggle the key in the start position to get the car to start, like it has 
> a
> bad contact.
>      I am still trying to figure out what I have for a car and
> need to drive and test it.
>      TR6 electrical is a lot more complicated than
> my TR3.
>      I am assuming that perhaps my starter solenoid is burned out.

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