The_Pied_Shadow

I'm far from a professional when it comes to understanding circuits, wiring diagrams, and electrical systems in general but I'm not a layman either. I've having various issues which all seem related to the wiring in the car and I'm not sure if each is it's own problem or all symptoms of the same issue. 1991 Rx-7 Coupe NA

1. Blinker Switch
The blinkers weren't working when I operated the switch. I suspected the switch maybe was bad but I haven't been able to totally confirm that. However, based on the wiring diagram it seemed like the switch was simple enough. It took a 12v current in from the connection at pass that current to one of two other connectors to either turn on the left blinkers to the right blinkers. So my idea was that for the time being I could rig up a On-Off-On toggle switch to replace the switch temporarily for troubleshooting purposes and until I got a proper switch. My plan was to run a wire from the pin on the connector that gave power to the switch, and then run a wire from each side of the switch to the respective pins for the blinkers. However, I checked the diagram to find out what pin in the connection would have the 12v power when ignition is on but got no current. It also occurred to me that the blinkers should be able to engage even with the ignition off so I checked each pin for something that gave 12v even without the key and found a pin. It wasn't at all the pin the diagram said it would be. I then attempted to route power to the pins the diagram said the blinkers should be and no luck. So I simple tried routing the power to each pin to see what happened. The original switch has control for both blinkers and the high beams. I found two pins which seemed to turn the high beams on, a pin for the left blinkers, a pin for the right blinkers, and also one pin which caused the light next to the rear window defroster symbol to turn on (which boggled my mind this switch doesn't even control that why would there be something in the connector for it?). The remaining pins I didn't notice anything happen when I routed power to them. Also there was a pin which gave power with when the ignition switch was on. This at least seemed to confirm to me that the blinkers worked fine and thus my switch was bad. I rigged up the toggle switch to the pins for the blinkers so I'd have temporary switches so I could use the blinkers until I got a new switch. Then it go weirder. Sometimes (not all the time but often) when I engage the left blinkers the head lights flash at the same rhythm but this doesn't happen for the right blinker. Additionally, when I turn on the headlights, neither blinker works. Again, mind boggled.

2. Add Coolant Alarm and Light
The light saying "add coolant" and the very loud accompanying alarm come on sometimes. Originally, it came on all the time and through a different thread found out it was because some previous owner had removed the coolant level sensor and grounded the wire and for some reason the wire was no longer grounded. I replaced the sensor and wired it back up. Not the alarm and light only come on sometimes. I check the coolant, it has coolant. I'm not leaking coolant to the ground, I'm not blowing white smoke on start up. Sometimes both the light and the alarm seem to fade in rather than just immediately starting at full strength (alarm starts quite and gets louder, light starts dim and gets brighter). The alarm will stop if I jiggle the white circular connector on the back of the instrument cluster (which I tried because I know the wire to the sensor comes out of there). This will almost always stop the alarm but sometimes only for a few seconds. After I go back and forth with it for a few minutes it eventually will leave me alone for a while.

3. Lights and Steering
I noticed just today to further mind bogglement that when I turn my steering wheel all the way to the left....my headlights turn on (they don't pop up just the lights turn on). Haven't had time to dig into that one so that's all I can say, that's what seems like is happening to me.

Really I'm looking first to get some people's opinions if it sounds like I have some wiring problem that is causing all of this or if it's more likely that these are separate issues that I need to address separately as well as advice on how I could troubleshoot or gather more information about these problems and /or things to try. Thanks everyone.

WondrousBread

I'm not an expert on our dash circuitry, but I recall there was a multi-pin ground under the trailing ignition coils that is important for the dash circuits. It's worth inspecting and cleaning. It bolts to the shock tower, white connector.

That would certainly not explain the headlights turning on when you turn the wheel though.

jts749

I agree with the above post, sounds like maybe trouble with multiple grounds.

The_Pied_Shadow

Thanks for the suggestion! There's a couple white plugs in this general location I'm going to clean them all but are there any more details you could give me that would help me identify it for sure? Is there anything about a grounding connector that is different that others in form?

WondrousBread

IIRC this particular ground is a bit weird. Basically on the back of the shock tower (facing the driver's seat) is a small metal piece. One side is a ring terminal with a bolt going through it, the other is a little set of pins that connects to the white connector I mentioned. It should be rectangular in shape. You'll want to make sure the pins are nice and clean, the inside of the white connector is nice and clean, and that the ring terminal & threads on the tower are clean. Use a fresh M6x1.0 bolt.

EDIT: Here, there's a photo of it in Aaron's guide https://aaroncake.net/RX-7/grounding.htm

The_Pied_Shadow

Ah I was definitely imagining the wrong thing. I see it down there now. I'll try replacing the bolt and cleaning the area see if that helps with anything.