Intermittent Speedo & Voltmeter problem
10-31-2009, 12:33 AM
#1
Burning Brakes
Thread Starter
Intermittent Speedo & Voltmeter problem
'82 5 speed.
I've been chasing a problem with intermittent instruments. My speedo and voltmeter are working sometimes - sometimes not. Sometimes they go out in unison sometimes one works and the other doesn't.
Last weekend I did a podectomy & burnished all the connectors & took a scothbright pad to the lugs on the underpod ground point. No help. (cleaned the grounds behind the central electrical panel about two weeks ago.)
Then on the drive home, after about a mile the voltmeter started working. After about 15 miles the speedo came back to life (the drive home was on rural back roads with 100 watt highbeams on most of the way). Next day - speedo, but no voltmeter. Next day, no speedo or voltmeter. Since then speedo has worked most of the time.
Yesterday I had to drive from NorCal to Riverside Co. (475 miles - 7 hours). Speedo worked the whole way. Voltmeter came & went - no voltmeter for about the first 300 miles, then it worked for about an hour & the next time I looked down, it was limp - then it started working again. Today everything was working normally.
Obviously, The system is charging - I wouldn't have made a 7 hour drive on the battery - & it certainly would not have started this a.m.
Tomorrow I have to do the return drive to Sonoma County.
I'm scratching my head. Any suggestion would be greatly appreciated.
James
I've been chasing a problem with intermittent instruments. My speedo and voltmeter are working sometimes - sometimes not. Sometimes they go out in unison sometimes one works and the other doesn't.
Last weekend I did a podectomy & burnished all the connectors & took a scothbright pad to the lugs on the underpod ground point. No help. (cleaned the grounds behind the central electrical panel about two weeks ago.)
Then on the drive home, after about a mile the voltmeter started working. After about 15 miles the speedo came back to life (the drive home was on rural back roads with 100 watt highbeams on most of the way). Next day - speedo, but no voltmeter. Next day, no speedo or voltmeter. Since then speedo has worked most of the time.
Yesterday I had to drive from NorCal to Riverside Co. (475 miles - 7 hours). Speedo worked the whole way. Voltmeter came & went - no voltmeter for about the first 300 miles, then it worked for about an hour & the next time I looked down, it was limp - then it started working again. Today everything was working normally.
Obviously, The system is charging - I wouldn't have made a 7 hour drive on the battery - & it certainly would not have started this a.m.
Tomorrow I have to do the return drive to Sonoma County.
I'm scratching my head. Any suggestion would be greatly appreciated.
James
10-31-2009, 01:07 PM
#2
Burning Brakes
James
Did you get a chance to test the foil strip itself? Checking for continuity from one end of the connections to the other can indicate a break in the path.
I am assuming that you have tested for proper voltage at the battery and the jump post to verify that the alternator is charging properly.
Did you get a chance to test the foil strip itself? Checking for continuity from one end of the connections to the other can indicate a break in the path.
I am assuming that you have tested for proper voltage at the battery and the jump post to verify that the alternator is charging properly.
10-31-2009, 02:07 PM
#3
Drifting
Probably the printed circuit has broken solder. My own speedo works intermitantly, when it does it rarely goes over 40 mph although the odometer seems to work in those circumstances. 928 International has new ones for about $100, although Dwayne has a howto on resoldering the PC on this site. I am going to repair mine over the holidays.
