Engine hesitation after electrical use


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By 'GB'ird - 16 Years Ago
Had a strange experience in my '55 T-bird last night. Whenever i operated the electric windows the engine hesistated quite badly then continued to hesitate or bog (is that the right term?) for a several miles then eventually picked up again. What's that all about? (The car is still running 6 volts + gnd). Thanks for any suggestions.

Richard

By Ted - 16 Years Ago
Assuming that the breaker points are in good condition, I’m going to suggest that you have a voltage drop at the coil when running the other accessories.  Putting a voltmeter at the positive side of the coil with the engine running while having someone else turn on the various accessories can help to verify this.  The problem can be stemming from a generator that’s simply not outputting enough or a battery that’s on the verge of failing.  Likewise, if the car has been rewired, then the wiring itself is going to be suspect but don’t rule out something as simple as a loose connection behind the ignition switch.
By 'GB'ird - 16 Years Ago
Thanks for your help Ted, I'll see what i can find. I really hate electrical problems.

Please God don't let it be the wiring!

Richard

By Doug T - 16 Years Ago
Since it was night it is likely you had the head lights on and maybe the defroster blower as well as running the windows, so it is highly likely that the electrical system was overloaded.  Since it is also over 50 years old it likely has some "quirks" put in it as well.  If you are off shore (GB?) it is even more likely that some bits and pieces that are sub optimal.

I have found old wiring is usually in pretty good shape under the tape that Ford wrapped the harnesses in.  The PVC insulation is usually OK but a little stiff if there has not been a short in the harness that has melted it. The end terminations are usually the problems.  Here the problems are usually corrosion, frayed wires, and cracked insulation. You can inspect for all of this although working under a T bird dash is second only to waterboarding as torture.  Repairs consist of renewing terminations with new terminals and re insulating back to sound wire by crimping new ends and short sections of new wire. 

By simplyconnected - 16 Years Ago
Those 6-volt generators only put out 35-amps, and only when the engine was running fast (over 1,500-rpm).

6(volts) X 35(amps) = 210-watts.  That's IT.  You only get enough power to light two 100-watt light bulbs.  It's easy to see, if your car was at low rpm for awhile, the battery was draining.  When you put an extra load (window motors), your ignition didn't have enough volts to operate correctly.

You can connect a volt meter, and see this happen.  In fact, if you mount a volt meter in the car, you will always know if your battery is under-charged.  A fully charged battery (with the engine running) should show 6.8-volts.  When you shut it off, the battery will slowly level-off at six.

Call Rimmer Brothers (UK).  They have gauges for six-volt systems.  Volt meters are extremely easy to connect without changing any of your wiring.  Hope this helps.  BTW, the other posts are right, your wiring is probably good.  Always make sure your connections are tight, especially on a six-volt system.

  - Dave Dare

By Hoosier Hurricane - 16 Years Ago
"GB"

Your Bird has a 40 amp generator, passenger cars had 35.  But the difference is of no consequence, and as Dave stated, they are nowhere near that amperage at idle.

Have you checked for a slipping fan belt?  That would cause the battery to be less than fully charged, and recovery time would be longer.  These cars didn't do that when new, so something has deteriorated.  Have the battery load tested, it should be able to operate the power windows several times before the voltage dropped enough to cause misfiring.  If you have an electronic ignition conversion, be advised they are low voltage sensitive. 

By 'GB'ird - 16 Years Ago
Thanks for your input guys. Actually it was a light evening and I had no other electrics on. The battery is fairly new and the fanbelt is fine. What really stumped me was why the car continued to hesitate badly for some time afterwards.

Richard