triumphs
[Top] [All Lists]

Re: TR3 ignition light?

To: TR List <triumphs@autox.team.net>
Subject: Re: TR3 ignition light?
From: Dave Massey <105671.471@compuserve.com>
Date: Tue, 10 Aug 1999 13:04:27 -0400
Cc: William Hook <wghook@earthlink.net> charset=ISO-8859-1
William Hook writes:

>My TR3 (still + ground) ignition light has me baffled..  When I turn on
>the ignition it shines bright and goes out when I start the
>engine....just fine... but it starts to glow when I reach 2500 rpms and
>gets brighter as I rev higher.   At idle or if I let off the gas it goes
>out.  The Ampmeter reads zero except when under load (ie blinkers or
>brake lights and reads -15 with headlights) and doesn't seem to respond
>as the light changes nor does it seem to recover from small loads like
>wipers (-5 or 6).  New battery - (reads +/- 12.9v no load to +/- 11.8v
>w/ wipers no engine).   After hard fast driving for several days (yes!
>it made it to the ATDI in Wenatchee WA - a great NW warm up for  VTR
>2000) my battery now is at 10.v and not enough juice for the
>starter...obviously not getting charged.    I had replaced the generator
>(2nd one - first was a dud).  I tried a new regulator and the ampmeter
>immediately went to +30 so I put the old one back in rather than fry
>everything.  The belt is new and tight and the gen .pulley is tight and
>has the woodruff key in.
>SO.....
>Is it possible that the generator or the regulator work only at low rpms
>and kick out just at high rpms?.
>Why wouldn't the light glow brighter at low rpms rather than just high
>if the system wasn't charging??
>Why would a new regulator  immediately over charge?
>
>Perplexed but really learning to love this car.
>Bill Hook ,
>rookie w/ 57 TR3 and now seriously wanting an overdrive..

Bill,

My guess is that the regulator is bad.  Consider this:   
>>>you replaced the regulator and the ammeter went to +30 
>>>the batttery is at 10 Vdc
>>> the Generator light glows at high revs

These symptoms suggest that the generator connect contacts 
are not closing allowing the generator output to go to the rest of 
the electrical system allowing the battery to discharge over time 
and at high revs the generator output voltage is reaching 16 - 18 
volts causing the light to glow.  

Remember that the light works off of the voltage differential of the 
electrical system (switched) and the generator output.  When the 
key is on the system voltage is at 12 Vdc and the gennerator is at 
zero (engine at rest.)  When the engine is started the generator 
raises to 14 volts and the contacts in the regulator close connecting 
the generator output to the system voltage to recharge the battery
and run the electrical loads.

When you installed the new regulator and started up the engine 
the regulator caused the generator voltage to run up to 14 Vdc 
and since the battery is heavily dischaged it pulled some 30 amps 
of charging current.

My suggestion is to reinstall the new regulator and run the engine 
with the voltmeter connected to ensure that the system is not 
overcharging the battery.  As long as the voltage does not exceed 
14.5 volts you are OK.

Good luck and BTW: no the generator does not only charge at 
low RPM's.  In fact it should work better as the RPM's rise.

Dave Massey
St. Louis, MO USA

<Prev in Thread] Current Thread [Next in Thread>