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jeverett New Beeper
Posts: 1
(1/23/02 3:08 pm) Reply
69 RR ELECTRICAL FAILURE WHEN HOT
New (remanufactured) Alternator (AC Delco),
New voltage regulator (Paddock),
New main engine wiring harness (Year One),
New ignition switch, ballast resistor, starter relay, starter, battery, ...... etc.
Amp Gauge shows normal discharge while starter cranking cold engine and shows initial charge (14.7 volts) once engine starts. After about 5 minutes of run time the Amp Gauge shows slight charge (12.7 volts). Everything appears to be operating normally for about half an hour.......then the engine dies. When trying to re-start it, the amp gauge shows major discharge with the needle pegged to the left and once it starts the gauge shows a major charge pegged all the way to the right. Then it dies again!! I can hot wire it from the battery to the coil (with the main harness disconnected) and bump start it at the relay and it runs fine. I can't figure out what the problem is but it hasn't run for more than 30 minutes even after replacing everything. Please help!!
I'll have to ponder for awhile but I think I dealt w/ this once. Seems I recall that I replaced a bunch of stuff at once and ended up ;eaving a wire to close to hot stuff. Go over ALL of the harnesses carefully and look at the routing.
I bypassed my cars w/ a big 8 gauge wire from the hot post on the alt. directly to the battery and it worked well. Lots of Mopar trouble comes from the bulkhead connector as all power runs through the alt gauge and strange problems happen because of the passing throught the firewall at that point.
'69 Road Runner 383 going to 440, 6brl hood, likely gonna race it
'70 Challenger R/T clone 440, 2nd owner, 300,00 miles on body, not kidding
'92 Cummins 1 ton, in need of restoration bad
'79 360 1 ton flatbed-for sale
'01 WS6 T/A- for sale
Re: 69 RR ELECTRICAL FAILURE WHEN HOT
You did not mention changing the coil. I would do that if you have not done so. I work as an Electronic Eng and used to work at a plant that supplied and built coils for vehicles and I do know that if the primary windings in the coil begin to fail they will increase resistance and draw more current. This would put a drain on your system quickly. It does also appear this is happening in the run mode and not in the start. You have changed evrything in the start. I also agree as previously stated it could also be wiring or bulkhead. Something heating up causing an increase in current, which a bad connection will do.
jeverett New Beeper
Posts: 2
(1/28/02 12:49 pm) Reply
Re: 69 RR ELECTRICAL FAILURE WHEN HOT
I replaced the coil too!
I work as a Mechanical Design Engineer for Northrop Grumman.
I absolutely hate electrical stuff.
You can't see those little pluses and minuses that magically fly thru those pipes called...wires!!
My latest findings are....when I isolate the regulator and full field the alternator I only get 1.4 amps. When the regulator is hooked up, the alternator pumps out 20+amps at 1200 rpm. It doesn't seem to care if it is hot or cold it still pumps out 14.8 volts and shows 6.2 volts on the field. My old motor manuals say 13.6V - 13.8V max with 1.4V - 1.6V field.
I have ordered a new 36 amp, single field, single pulley alternator.
I believe the "re-manufactured" 60 amp, double pulley, square back with the secondary field clipped and grounded to the housing from the manufacturer.....is a piece of junk!!
I will post the results when the new alternator arrives, is installed and tested!!
Thanks for your input.
jeverett New Beeper
Posts: 3
(6/23/03 2:11 pm) Reply
Re: 69 RR ELECTRICAL FAILURE SOLVED!!
Bad Alternator.............Burned instrument cluster.
Replaced it all......A Year and a half later....Runs Great.
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