Welcome, Guest. Please login or register.

Login with username, password and session length

 
Advanced search

3886 Posts in 1208 Topics- by 2247 Members - Latest Member: Steve Ahmann

May 23, 2012, 02:11:20 AM
Maintenance IssuesTR6Voltage gauge: pegged
Pages: [1]   Go Down
Print
Author Topic: Voltage gauge: pegged  (Read 669 times)
Lazslo
Newbie
*
Posts: 11

1976 Triumph TR 6


« on: August 06, 2011, 12:01:55 AM »

My voltage gauge is fluctuating between normal and fully pegged (red line). Is there any suggestion as to how to test for bad alternator/voltage regulator or bad gauge? It's on my '76 TR-6, and any suggestions would be appreciated.
Thanks,
Laz
Logged
TR3driver
Full Member
***
Posts: 245



« Reply #1 on: August 06, 2011, 09:48:46 PM »

A digital multimeter is one of those things that every LBC owner should have.  I literally carry one in each Triumph!  If cost is an issue, a cheap unit (under $5 on sale at Harbor Freight) will do.

Set it to a DC volts range that will cover 20 volts; then start checking voltages at various points.  I would probably start at the battery terminals, since overcharging the battery is the biggest concern.  Then check directly at the alternator output (case and big Lucar connector).  If either of those are above about 14.4 volts, then there is a problem with the regulator or the wiring to it.  If both look OK, the final test would be on the terminals of the voltmeter, while it is reading too high.

However, if you need to do something right now and don't have a DMM handy, check the battery cells when the voltmeter reads too high.  If the voltage is really going that high, all of the cells will be bubbling vigorously and the smell of sulfuric acid will be quite apparent.
Logged

Randall
58 TR3A TS39781LO :(now totaled Sad
56 TR3  TS13571L daily driver
71 Stag LE1473L waiting for engine rebuild
71 Stag LE2014LBW waiting for 4-speed rebuild
Lazslo
Newbie
*
Posts: 11

1976 Triumph TR 6


« Reply #2 on: August 17, 2011, 05:23:40 PM »

The mechanic has checked via his volt meter and the alternator/voltage regulator seem ok. The pegging of the meter is not constant, but rather it peggs, then returns to normal. Had the TR6 out today, and there was no bubbling or smell apparent. Seems more like a gauge, or connection.  The battery is 5 years old, and could a failing battery cause these symptoms?  Voltmeter suggests that the battery is good however. Time to crawl under the dash to check connections, I guess.
Thanks for your reply.
Logged
TR3driver
Full Member
***
Posts: 245



« Reply #3 on: August 17, 2011, 10:44:57 PM »

Hmmm, Did the mechanic check the battery voltage _while_ the voltmeter was pegged?

Offhand, I can't think of any wiring fault under the dash that would cause the voltmeter to read too high. A bad battery wouldn't do it either. If the battery & alternator output voltages are OK when the symptoms are occurring, then my next guess would be the voltmeter itself.

FWIW, when I tried to calibrate the voltmeter from my 71 Stag, I discovered that the adjustment was so loose that it would change on it's own.
Logged

Randall
58 TR3A TS39781LO :(now totaled Sad
56 TR3  TS13571L daily driver
71 Stag LE1473L waiting for engine rebuild
71 Stag LE2014LBW waiting for 4-speed rebuild
douglas foster
Newbie
*
Posts: 4



« Reply #4 on: August 28, 2011, 06:41:27 PM »

the dark side of Lucas
« Last Edit: August 28, 2011, 06:47:18 PM by douglas foster » Logged

VTR Gold 2002
Pages: [1]   Go Up
Print
Jump to:  

Theme orange-lt created by panic