kevin2012

My 95 993 cabio has a strange problem and need your advice.
When I turn the AC on, the intermittent wiper is on too.

I had replaced the battery and the intermittent wiper relay with a new one, it is improved but still happen from time to time. Meanwhile, I just have to remove the intermittent wiper relay until I can solve this problem.

Cheers

phoneyman

1 potential cause is a ground loop/ bad ground connection somewhere. Have you investigated if the AC and wipers are grouped together in wiring diagrams or if they share any other common relays or fuses?

How does the ground strap from your battery look? If theres any corrosion, it might help to polish or replace the cable. Other than that, unfortunately, its probably pretty deep in the car. Electrical problems usually end up being a b!tch.

kevin2012

Thanks for the advice, I will clean all grounding points in the front trunk. As I can see, there are only 3 grounding points there. Two on the left and one on the right. Any more? The battery negative cable is in great condition.Cheers.

kevin2012

The wipers problem seems solved after I had cleaned 4 groundings in the frunk and 2 in the engine room.
Thanks phoneyman for helping out.

phoneyman

Glad it worked out, Kevin. Since more systems in the car are analog, a lot of electrical issues end up being either a faulty ground, or the battery isnt supplying the correct 12.7V, making the other electronics that rely on constant power, start to act funny when the battery reaches, say, 11.5V.