I saw a post recently about continuously dimly lit turnsignal intrument lights, and I noticed the same thing on my '74 145. It didn't seem to affect anything else until now.

I had a dead battery after driving home after dark with the lights on the other night. I tightened the fan belt and cleaned the battery terminals.

When starting from cold now, I notice the turnsignal indicators start to glow and get brighter. They go out when I flash the headlights with the high beam, and gradually come on again. for the first few minutes of driving, the engine stumbles when I turn on the headlights. It immediately runs smooth when the headlights are shut off.

I suspect the alternator and maybe even the small battery are marginal, but I never get an amp light while running, only when engine-off/key-on.

Since someone else has seen these dimly lit indicators, I bet several of us have. Anyone nail it down for sure?

Thanks MP.

All of my VW's, which have been late-production air-cooled (REAL) Beetles, ca. 1973-74, have had this problem. Or non-problem, depending on your point of view. The charging system is electrically identical, as far as I can tell. The physical arrangement is different, but the parts involved are the same.
I saw this with both Bosch and Motorola alternators that were fitted to different cars and functionally identical.
I always chalked it up to poor (i.e. high-resistance) grounds on the instrument cluster, the engine, and the battery cables themselves. These units never failed to charge (except for one regulator failure in almost 15 yrs of use). They always lit the turnsignal light just a bit, and maybe the alternator light dimly as well. Like yours it would change or go out when the headlights were used, and fade back on a bit later. I always found 13.5 V or so when I checked system voltage... not strong, for sure, but I was able to verify with an ammeter that it was in fact charging, and after all it didn't take that much juice to turn these cars over. Nice clean battery terminals seemed to reduce the brightness of the light, but not turn it off. It did seem brighter when the lights were on, but hard to say... and now my last VW is a '70 Bus with a generator, so that's totally different.
I would say, if you get consistently good system voltage, and the connection points throughout the system are clean and tight, enjoy the green glow!
--
Rob Bareiss, New London CT ::: "Roterande Fläkt Och Drivremmar!"

The glow seems to decrease after driving for about 15 minutes.

I want to suspect some connection that may be subject to thermal expansion, like at the back of the alternator directly under the exhaust manifold, just to make it interesting, but that big connector block where the secondary connects to positive, just off the battery, is all wrapped in tape and therefore suspect, plus there's a crimp-on at the clamp itself.

I suppose I could take five minutes out of my busy day and fix these.

When bad, it apparently affects the spark, and makes the engine stumble.

Thanks. MP

Be sure and put the year in your post headings. It makes a difference.

On most 140s and earlier Volvos the amp light and the turn signal are on
the same fuse and problems with that fuse or its connection are responsible
for some really weird effects. Normally they do include a glowing amp light
though.

If your battery is going down, it might be clear back at the alternator's
isolation diodes. I've had that problem several times over the years but
again, it was usually accompanied by the glowing amp light.

It really sounds like some kind of a ground problem, either a loose ground
or maybe a short to ground in a relay or some such. Might put a meter
in series from the battery circuit with things turned off and pull fuses
till it indicates no continuity. That would tell you (maybe) where the "leak"
is.
--
George Downs, The "original" Walrus3, Bartlesville, Oklahoma

I would agree with George about the grounds. Since the negative cable grounds to the body ,it might be advisable to put in some redundant grounds from bat. to engine & body. 8 or 10 gauge should do it. Another test for grounds is to use a dig.volt meter[dvom] from neg.cable to engine grd.,alt grd.,etc. You should have less than .1 volt. If more ,then you have a bad or corroded conn. or bad wire. Check the fuses & clean scrupulously with wire brush or sandpaper & replace all fuses periodically too. This is a REALLY common with all ceramic bullet style fuses. Another test for battery drain is to disconnect the neg. cable & put a test light between the bat. & the cable. If the test light glows FULLY there's a circuit on somewhere. Disconnect fuses &,or access. to find the culprit. Be aware that none of the circuits will work during the test & ANYTHING![ie door open] on electrically will activate the light. Good luck

Mike M.