Greetings RX7club.com! Recently purchased a 1986 base model, been dismantling and checking everything over and have run in to a few issues I can't seem to sort out. I did try searching, but wasn't able to find anything similar enough for these two issues.

First, the dome lights don't seem to work. The main vanity light and the two individual side lights do not function at all. I've tested for power across the fuses, which are all fine, but there's no power making it to the switches themselves. Any idea where I should be looking for common faults here? Other interior lighting (the dash, radio, hvac) don't seem to have issues.

Additionally, my wipers only seem to work when the switch is set to I. If it's set to Int or II, the wipers will just freeze in place wherever they might be, and they don't function. The motors seem to be just fine as they don't struggle at all when set on I. Any advice on how to diagnose this?

Thanks in advance!

 

welcome to the forum. as a new member i would suggest downloading a copy of the FSM and wiring diagrams. good luck.

 

Yes, I have already done this. I was looking for specific advice on where to start my search rather than fumbling blindly.

 

As an aside, all the links in the newbie FAQs basically lead to malware. Probably should get those updated. Many of the forum links are dead and lead to parked domains that ask you to install browser extensions that are known to be traffic scrapers. Less savvy users might think they actually need to install these to access the content.

 

This will most probably fix your issue: FC3S Pro v2.0:&nbsp How-To - Fixing RX7 2nd Gen Wiper Switch
Searching the forum for wiper switch also gives you plenty of threads. You can also use the Google search option and search for "2nd wiper switch".

 

Relays aren't bad, already tested them. The switch itself is fine. That link explains how to replace a relay that is confirmed to be bad, not really anything else. Gone through all the service manuals and followed all testing procedures and haven't really found anything that jumps out as being incorrect or broken.

I have used forums before. I know how to use search and I know how to use google. But you're right, someone, somewhere, buried deep in a thread probably posted the solution to my issue, and it's my fault for not spending 10 hours digging through nearly 20 years of threads and conversation to find it.

Thank you for the suggestions.

 

You didn't mention you already checked the relay and your symptoms are dead-on for stuck / non-conductive high-speed relay. Do they park by themselves if you turn it off? When the wipers are parked and you turn them to INT, do they move up a bit?

If the relay operate correctly the only way II won't work (at least from what I'm seeing) is that continuity on the motor supply is broken. There are two things on the switchboard side you can check:
- The relay has a proper ground
- The relay has a proper connection to the motor supply
As a note, the switch works in the following way: There are two power supplies for the motor, for LOW and HIGH speed. Both these get voltage on the motor's end while the relays in the switch ground these lines. The 5-pin (middle or upper) relay grounds the LOW speed one, while the bottom relay grounds the HIGH speed one.

If these work you can check if the HIGH speed line is connected to the motor.
I attached an image marking the appropriate pins. You want to test GROUND to the B pin in the connector, and the LR marking to the LR pin in the connector (LR and GROUND markings are two sides of the normally-open side of the relay). Additionally you can check the LR cable going to the motor. If the relay closes properly on the II setting one of these should be broken.

The soldering on this board can also be quite bad so having a go at generally resoldering everything might fix it too.

 

I rechecked everything for a third time, and there must have just been something loose (or possibly some corrosion buildup that was hard to see) because I changed nothing, put it all back together, and it's working properly now.

 

Either that or some of the solder joints are a bit bad. When mine didn't park it fixed itself after I replaced the relay (which did fix my speed II issue, but was probably unrelated to parking), then decided to break itself after a while. If it breaks again I'd resolder everything.

 

Indeed, seems I did speak too soon here. Took everything apart again and was going to reflow the solder just to be on the safe side, and found a blown component. Not sure exactly what this is, probably a transistor? I can replace it easy enough, but having difficulty finding exactly what this part is.

 

That should be a PNP transistor. It has something to do with INT / Park, but I'm not good enough at electronics to figure out how exactly that part works.