Question about 1977 idiot lights

[jdbunda]

I drove a '77 coupe last night, owner wants to sell. There were two idiot lights on that he claims go out after 10-15 minutes of driving. Temp and oil pressure gauges indicated normally while we were driving, but the lights never went out. They did seem to vary in brightness a bit with revs. The owner had no idea what they meant.

Here is a "borrowed" pic of a 77 dash - the second light isn't shown (or maybe I remember it wrong, and it was to the right of the speedo?) Can anyone tell me what these lights might mean? Thanks for any advice.

[Walter_Middie]

The light on the left, inside bottom of the oil temp and pressure gauge, is the alternator light. It should come on when you first turn the key to the run position. Once the car is started and the revs get over 1500 to 2000 RPMs, the light should go out. If it does not go out, your alternator is not generating enough juice to recharge the battery. It may vary brightness with RPM - could be the voltage regulator.

There is another light on the dash near where you have circled on my 1975 that is marked EGR (exhaust gas recirculation). This is a little bit of a mystery to me as my car never had EGR. I don't know if the 1977 had it or not.

No idiot light should stay on for the first 10-15 minutes of driving unless it is monitoring the sellers BS meter.

[1976 TN Porsche]

+1 ON Walter.

[The pat holland]

My EGR light came on I tightened the battery connections and it went off …… and stayed off 1000s of miles since. It was actually learned from a post here but I can’t seem to find it

[HaroldMHedge]

On my 914, I think the alternator and EGR lights were tied together. Yes, it does appear to be the same for the 77 911.

1977 911S Alt + EGR light on

EGR could also require a reset but going out at an increased rpm indicates a charging issue to me.

EGR reset?

[spuggy]

Originally Posted by HaroldMHedge

On my 914, I think the alternator and EGR lights were tied together. Yes, it does appear to be the same for the 77 911.

1977 911S Alt + EGR light on

EGR could also require a reset but going out at an increased rpm indicates a charging issue to me.

EGR reset?

^^^ This, what Harold (and Walter) said.

Originally Posted by jbunda

Here is a "borrowed" pic of a 77 dash - the second light isn't shown

Heh. Nice try...

That seems to be a RoW car, not fitted with EGR. Note the temperature gauge is calibrated in Celcius, not Farenheit, and oil pressure is calibrated in bar, not PSI...

From the US '77 Owner's Handbook: