QuestionQUESTION: Everyone tells me these cars were known for their electrical idiosyncrasies--but can't seem to find the solutions. The problem is with the "run" circuit---it starts fine but as soon as I release the key from "start", it stalls. One of the problems making it difficult for me to diagnose is, it is an intermittent problem. Also, when the "run" circuit decides to work, it stays functional until the engine is turned off. It appears to have a "Lumitron" ignition...possibly aftermarket? I've checked all fuses and fuseable links; all ok there. I also was able to make the car run by energizing one of the four bus fuses on the r/h wheel well, but am sure this is not recommended.
Any help is much appreciated!!
ANSWER: As I think you suspect already, it's most likely the switch going bad and losing contact with the ordinary ignition circuit on returning from the Start position. You can check that with a testing light or voltmeter at the coil: if the theory is right, the live connection (from the switch) to the coil will go dead when it fails. You might also try a wiggle test: get the testing light on the coil and get a helper to wiggle the key between Run and Start. Does the light go on and off?
Before you get a new switch, try squirting some WD40 or other switch cleaner into the keyhole and then go all the way back and forth to try and clean the contacts. (I would disconnect the battery first!)
I don't know about Lumitron (I would think the original would be Lucas), but I'm sure replacement B switches should not be hard to find, e.g. Moss (US) or UKMGParts (UK).
Good luck--
Jo
---------- FOLLOW-UP ----------
QUESTION: Thanks for the timely response, Jo! I failed to mention initially that I believe I eliminated the key switch as being the culprit in basically the same way you had mentioned.
Since we've been having an extreme amount of rainfall in our area this spring (I'm in Maine), I'm beginning to believe this problem is due to a combination of two things--(a)moisture, and (b)having recently found the inside of the distributor cap to be quite foul-looking (after drying out a LOT of moisture in it!). After drying everything out with a heat gun, the car seems to run fine, and with over a dozen starts there are no glitches. I'm wondering if it's possible that a bad-looking and/or wet dist. cap could provide enough starting spark, but then with less voltage in the "run" position fail to produce enough current to the plugs. (?) I'm curious as to what your thoughts might be on this matter. Thanks!
AnswerAh! I don't know why damp ignition would produce your symptoms (why it's OK in the Start position but not Run), but if the switch is not totally healthy, that might explain it. But here are general recommendations for distributors and damp.
Clean the coil and plug wires and connectors with WD40, and leave a little on them. Make sure the low voltage contacts on the coil and distributor are also clean: WD40 again. For the cap, a good solution (after cleaning inside of course: WD40 yet again!) is to remove the wires from the cap, clean and dry the ends, and then put a good blob of silicone grease (not glue) on the ends before reinserting them. That keeps the water out well. In my mis-spent youth we even used rubber gloves over Lucas caps: the middle finger gets the coil wire, and the remainder are for the plug wires. Get a latex glove and cut a tiny hole in each one for the wires. Good luck with it. (I'm on Long Island, where the US open got drowned in the same weather!)
Jo
PS I hadn't even thought of that, despite in distant times past whacking starter solenoids with a tire iron! I will definitely file it in my mind. Thanks for the feedback.
