See my comments below
Don Elliott
> Dave Barrans wrote:
> > > > 1. I have power on the green wire to the turn signal flasher unit.
With the
> > turn signal in the middle position a dim test lamp on the green-brown
wire
> > coming out of the flasher, in R or L turn position no lamp. Does this
> > indicate the flasher is bad or do I need to go further?
>
> Sure sounds like a bad flasher to me, assuming it's wired correctly.
>
> > 2. Will the overdrive solenoid move if the engine is not running and the
car
> > is not moving? I have power to the solenoid in 2,3 and 4 (test light)
> > engine off, ignition on, but the solenoid does not move. Is this normal?
>
> Nope, the solenoid will move (and make a audible click) even with the
> engine off and the car stopped. Most likely, the pull-in contacts
> inside the solenoid have failed. However, it's only serviced as a unit.
>
> Randall
2. There is one wire into the solenoid. When you switch on the overdrive
the major coil inside the solenoid (the "pulling" coil) draws lots of amps
for a fraction of a second to clack in the solenoid. When the solenoid
plunger gets to the top, it opens a small blade switch to cut off the
"pulling" coil and the current drops down to say 0.5 amps or so.
If you click the solenoid on and it draws say 0.5 amp but the plunger does
not pull up, it means that the "holding" coil is energized but there is not
enough "pulling" power in the "pulling" coil to pull up the plunger.
If the solenoid is out on the bench you can check the resistance values for
the coil using an ohmmeter.
With the plunger down or out, the resistance for the "pulling" coil should
read about 2 ohms if the "pulling" coil is good. If the coil reads 15 ohms,
the "pulling" coil is defective. You are only reading the resistance here
for the "holding" coil.
Now put the plunger in and push it up so that the blade switch inside the
top opens the contact. The resistance should read
15 ohms for the "holding" coil.
Remember your high school physics ? Two resistors in parallel give a lower
resistance value than either one alone.
Solenoids can be repaired sometimes. If it is the older Lucas type, take
off the top boot carefully, flatten the lock-tabs, unscrew the small hex
nuts (make sketches at each stage) and check the wires. Maybe they only
need to be re-soldered back onto the terminals. Strip off the polyuretane
insulating varnish if needed and solder the wires back on.
Clean the contacts for the blade switch with a small file. If you use
sandpaper, the sand may stay enbedded in the blade switch and after about 20
times, it won't work anymore. Re-check the resistance values again as above
and then (if it works) carefully re-assemble it as per the sketches you
made.
Because the blade switch opens many times over a period of say 20 or 30
years, there is some arcing and this can cause the blades to become like
"old points" and then in the "off" position it is like the blade switch is
"open" and it won't draw in the 25 or 30 amps it needs to "pull" in the
solenoid. Cleaning the blade switch contacts corrects this.
I found this out during the 4 or 5 times that I repaired my solenoid. But
once I needed a spare so I bought one from Moss while I was at VTR in
Portland Oregon. It worked for only 3 months so I returned it for a
replacement. I didn't want to open this one up while it was still
guaranteed (12 months). This new one worked for 3 months, so I took off the
top rubber boot and found that it is slightly different in construction. I
found they seal the new ones with gobs of white RTV silicone sealer. A
chunk of cured silicone had come loose and was keeping the blade switch in
the "open" position. I pulled it out, re-assembled it and it has worked
ever since.
I also repaired my original solenoid and it is now my spare. It is stamped
Lucas and is dated 1954.
To make it easier to change my solenoid, I cut a hole in the side wall of
the tunnel to remove the solenoid . The hole is about 4" in diameter. I
fill this hole with a spare floor plug for the TR3A jack hole. Right above
the two round-head screws securing the solenoid, I drilled two other holes
about 3/4" diameter to fit a long screwdriver straight down to remove the
solenoid screws. I use spare rubber plugs that fit holes in the firewall to
close these two holes in my tunnel.
Now I can change a solenoid in less than 10 minutes on the road. But it
takes me 30 more minutes to get my toolbox out and to reinstall all the
stuff in the trunk afterwards.
Don Elliott 1958 TR3A
Montreal, Canada
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