dash lights, tach, and headlight help:

OK, I'm a new Porsche owner and I need to replace a light bulb or two in the dash, near the hearer/air/fan levers in a '74 911. I've purchased the Clymer and Haynes manuals, but as far as I can tell, neither covers these interior items. I have the original owners manual, but no luck there either. Can someone tell me how to get at these bulbs without (potentially expencive) trial and error?

Also, my tach "bounces" slightly when up/downshifting, and takes a second to stabilize on the correct/current RPM reading. Is this normal? It does NOT read high or erraticlly at idel, or anything to suggest voltage regulator problems as described in earlier posts.

Lastly, my high beams do not work correctly (converted to H4's):
1.) On the speedo I get the green light for parking lights, no light for low beams, but also no blue light or high beams.
2.) When the driving lights are on, they stay on with no other external lights on, and with parking lights on.
3.) If I leave the driving lights on when I turn the headlights all the way on, the driving lights go out.
4.) With the driving lights on, when I try to switch to high beams the headlights go out, and the driving lights come on (a cool effect when flashing another Porshe, but I assume somthing is wrong). Could this be somthing simple like a headlight relay (please, please, please)?

Mike H
hansen441@aol.com

You can pull the gauges out by slowly pulling on each side of the metal bezel that is sticking out of the rubber ring that seals the gauge into the dash. That will let you get to the bulbs behind the guages or other areas in the dash. Tach bounce is caused by worn out electrical parts (ballest resistor?) inside the tach and has to be repaired by a speedo/tach repair shop. It can also cause the needle to be slow indicating the actual RPMs so if you autocross it could lead to over-reving the engine. On our car, the driving or fog lights should be on with low beams only (stock setup) and go out with change to high beams. There is the light to tell you parking lights are on and a separate or blue light for high beams. The high beam bulb may be out or as on our 914 it is very dim. Did the lights work okay before the H4 conversion? If so then probably the higher current of the H4 lights has caused either the light switch or dimmer/turnsignal switch to go bad.