1974 Problem-Turn Signal Indicator on Dash

[Paul L.]

The right dash indicator on my 1974 works fine. The left blows the #1895 bulb consistently. At first I thought it was just a bad bulb but I went through two new today before not taking that exercise any further. The actual/external turn signal lights front and rear on both sides work fine. So why is the right indicator light OK and the left troublesome?

[Martin N.]

Re: 1974 Problem-Turn Signal Indicator on Dash

PAUL-
I just noticed last night that my left t.s. indicator bulb is out on my 74. All the external bulbs and functions are fine. How does one go about replacing it. Seems kinda tight under there. This is the first time for mine in 7 years, and I haven't been into the dash on my car yet. Perhaps yours is a issue of jarring the bulb (being so tight under there) during installation and the filiments are touching each other and shorting out?

Marty

[Paul L.]

Re: 1974 Problem-Turn Signal Indicator on Dash

Marty,
You can get at it. I used a flashlight and a mirror to locate it (light blue single wire), then got my hand up there without losing too much blood.

I tested the bulbs with the socket hanging down loose so jarring is not the problem. I bought some more #1895 bulbs this morning and will fool about this afternoon but would certainly appreciate comments here so I don't just blow more bulbs.

*Edit*-Re hanging loose, I am wondering if I have lost ground for that bulb socket by not reconnecting it to the dashboard??

[William C.]

Re: 1974 Problem-Turn Signal Indicator on Dash

Yes, the ground is via the dashboard if it is attached with a single wire.

[Paul L.]

Re: 1974 Problem-Turn Signal Indicator on Dash

Yes, the ground is via the dashboard if it is attached with a single wire.

Yes, a single light blue wire. Thank you for that tip! I should have read between the lines in the shop manual. It does not mention the consequences of testing the bulb with the socket detached from the speedo unit, i.e. without ground. But the clues are there for a good detective. The diagrams show both speedo and tach units with male spade connections for grounding through the dash harness. I should have twigged to that and the fact that all bulbs in those units ground through the units' casings . By testing the bulbs with the socket hanging loose I was dealing with an incomplete circuit.

All is well now and the left turn signal indicator is happily showing flashing green. My thanks for the comments!