carnut1

My 1979 RX-7 started having the low oil, low coolant and charge lights flicker on starting last week. Now they stay on whenever it runs. It also now has the tach reading at 3000 rpm at idle as well. If the turn signals are used, the tach needle bounces down 500 rpm in sync to the dash arrows flashing? My thought is loss of ground somewhere? and the turn signals are feeding back thru the tach. Where would be the most likely area to check. Ignition switch wiring or behind the cluster? Thanks in advance, Bill.

Rogue_Wulff

Actually, it's something in the charging system. The lights are supposed to come on when the key is on, engine off. It uses a signal from the alt to shut them off.
Since your car is a 79, the tach also doubles as a volt meter, when the key is on, engine off. That's what the lower set of numbers are for.
It could be a bad connection at the alt, voltage regulator, or battery. Could be a bad alt or VR, as well.

carnut1

Thanks so much for the quick response, makes sense! I'll ck and report back.

Rogue_Wulff

No problem. You would have figured it out soon enough, as the car wouldn't start due to the battery being discharged.
One thing I love about the RX7, no matter what year it is, all the warning lights will come on if the alt quits charging. Especially handy when the air pump is removed, and only using one belt to drive the alt and water pump........

carnut1

Whats odd is that there have been no weak battery issues. This car is driven almost every night for at least 30 min. Could there be a specific wire at the VR that would affect the red lights but not affect charging?

Rogue_Wulff

Over near the VR, there should be a "check relay" this the relay that controls those lights.
If everything checks out in the charging system, check that.