2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

Electrical; wipers

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Old Jan 6, 2011 | 10:18 AM
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From: SanfrAnn Arbor
Electrical; wipers

Lucy's auto-return has never worked. There's also a couple setting on the combo switch that don't work. Is the auto-return in the wiper box itself, the BCM, or the combo switch?
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Old Jan 6, 2011 | 11:04 AM
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Isle rotory's Avatar
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HI Wacky Wipers

Aloha,

My 7 suffered this years ago and the only fix at the time was to replace the cluster which controls all wiper functions.

My wipers are starting to go intermittent again, sometimes they work properly sometimes not at all. I am going to look around to see if someone is rebuilding the clusters and doing a core exchange.

Hope this helps.
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Old Jan 6, 2011 | 11:20 AM
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From: Behind a workbench, repairing FC Electronics.
Please do a search, there are several threads on this topic, one if which is right on the front page of this section.

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/windshield-wiper-washer-936579/

This is what I have to say about the internals of the wiper switch assembly:

Originally Posted by Pele
There are two relays for the front wiper and one additional one for rear wiper equipped cars...

One is a small relay. It is responsible for the auto-park feature that will bring the blades to the bottom of the glass. INTermittent delay relies on this feature as it will pulse the motor up and then the auto-park feature will bring it down to the bottom.

If this relay fails, the wipers will NOT return to the bottom of the glass when you turn the switch off... However, all other features should remain operational.


The second relay is for High/Low speed selection. HOWEVER, keep in mind that auto-park and intermittent will use high speed to move the wipers. Hence if this relay fails, you will not only lose high speed but intermittent AND auto-park. This is the #1 failure in wiper switches.

The third relay in rear wiper equipped vehicles is simply another auto-park relay for the rear wipers. It usually does not fail for a two main reasons... The rear wiper is less often used than the fronts and the rear wiper does not consume as much power as the fronts. It has a smaller motor and only one blade to move versus the two blades and rack under the cowl. Its mechanism is also not subject to the weather...


Now, the relays fail because they are of a TWO PIECE design... That is, they are a regular open relay with a plastic cap over them. You can both feel and see a little groove between the base of the relay and the cap. Occasionally, I find oil and/or water in this groove showing that environmental (Moisture, humidity, etc.) has gotten inside the relay. This contamination will corrode the contacts inside the relay causing them to not pass as much power. (Due to increased resistance in the circuit.)

Also, originally the relays in the switch were standard copper contacts. They were rated for 5 amps I think... This is about what the wiper motor takes when starting up, so already from the factory, you're right on the limit... Add the reduced power capacity due to the corrosion and you have a perfect recipe for failure. I have seen numerous relays pulled from FC wiper switches where the clear plastic cap has become warped and discolored from the heat produced by failed contacts.

The new, updated relays as spec'ed out by Icemark's writeup are sealed... That is they assemble the relay and have a layer of adhesive to completely seal up the relay. No moisture can enter and destroy the contacts.

The contacts are also of a silver allow according to the spec sheet. They are rated to 8 amps, so they have more current carrying capability.

If I can find some of the old relays that are good examples of failure and a good macro camera, then I will post up some pictures of the failures... I usually send the old relays back to the customer so that they can see the damage first hand.
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Old Jan 6, 2011 | 11:37 AM
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From: SanfrAnn Arbor
So the relays are in the switch itself? Because I pulled the combos and turn signal stalk from a junked S4, and they looked in great shape on the outside. Going to have to see what pins need rearranging though. Pele, what's your charge for replacing the relay?
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Old Jan 6, 2011 | 01:19 PM
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Business in PM please.
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