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tri cabin wiper motor grounding

Posted: Tue Sep 08, 2020 10:41 am
by swampman
im having a problem with my wiper motors, i believe is a bad ground thru the frame . typically if i turn one on it does not work , however all the indicator lights come on as if all three are turned on . If i smack the windshield frame the one turned on will move and the indicators for the other 2 will blink off briefly . I have 3 power wires going up the frame on the port side and i believe just a washer hose on the starboard , but i didnt see a ground wire . anyone know for sure how the frame is grounded ?

Re: tri cabin wiper motor grounding

Posted: Tue Sep 08, 2020 9:49 pm
by RWS
had a similar problem with my 10 meter many years ago

as I recall I added a really heavy ground wire from the frame to the battery negative and then ran ground wires direct to the wiper motors

RWS

Re: tri cabin wiper motor grounding

Posted: Wed Sep 09, 2020 8:58 am
by mikeandanne
Try to check if there is continuity between the frame and your battery negative directly, that will tell you at least if it is actually grounded or not and the quality of the ground if any.

Re: tri cabin wiper motor grounding

Posted: Wed Sep 09, 2020 4:02 pm
by swampman
mikeandanne wrote: Wed Sep 09, 2020 8:58 am Try to check if there is continuity between the frame and your battery negative directly, that will tell you at least if it is actually grounded or not and the quality of the ground if any.
I know with all the fiberglass between the batteries and the windshield frame , it is not grounded directly . Somewhere a ground wire is routed , i was hoping to find exactly where before doing a bunch of intrusive dismantling in areas that may not need to be disassembled .

Re: tri cabin wiper motor grounding

Posted: Wed Sep 09, 2020 6:28 pm
by mikeandanne
When I said directly I meant with a ground wire somewhere . If you connect one side of your meter to the frame and the other to the battery negative or engine ground and show continuity then there is a ground wire somewhere that is still working, might save all the hunting.

Re: tri cabin wiper motor grounding

Posted: Wed Sep 09, 2020 10:57 pm
by P-Dogg
Drop your headliner. Inspect frame attachment bolts. Mine is grounded through one of them.

Re: tri cabin wiper motor grounding

Posted: Fri Sep 11, 2020 8:39 am
by swampman
P-Dogg wrote: Wed Sep 09, 2020 10:57 pm Drop your headliner. Inspect frame attachment bolts. Mine is grounded through one of them.
thank you P Dogg!, that is the kind of concise information i was looking for . although i didn't want to tear into the headliner .
maybe ill wait till i replace the port engine .

Re: tri cabin wiper motor grounding

Posted: Fri Sep 11, 2020 5:44 pm
by P-Dogg
Most welcome. In the meantime, as a temporary fix, you could run a wire from the ground available in the helm console, to any existing screw into the inside of your windshield (or install a new screw, depending on your tolerance for extra holes in things -- mine is near zero).

When you do pull your headliner, consider adding insulation above it. I am considering installing the reflective bubble-wrap variety next time that mine is down, to reduce air conditioning loads.

Re: tri cabin wiper motor grounding

Posted: Fri Sep 11, 2020 5:49 pm
by P-Dogg
After further review..... You may be able to access the windshield attachment by only pulling the plywood piece that spans the slope at the overhead height transition. If you can find and reach the ground wire bolt there, you may be able to avoid half-assing it, or waiting. Wipers are a safety feature that you should not go without.

Re: tri cabin wiper motor grounding

Posted: Mon Sep 14, 2020 8:32 am
by swampman
P-Dogg wrote: Fri Sep 11, 2020 5:49 pm After further review..... You may be able to access the windshield attachment by only pulling the plywood piece that spans the slope at the overhead height transition. If you can find and reach the ground wire bolt there, you may be able to avoid half-assing it, or waiting. Wipers are a safety feature that you should not go without.
As the season is almost over it can be added to the list of winter projects . I pulled the headliner in the forward berth to remove the inner glass skin and rotted balsa coring on the starboard side . was not fun getting that headliner pulled back into place and looking acceptable , so ive been reluctant to do it in the main salon . I would like to remove the entire windshield tho and recondition it over the winter .

Re: tri cabin wiper motor grounding

Posted: Mon Sep 14, 2020 5:54 pm
by P-Dogg
When faced with a zero-extra width piece of fabric after I took down the overhead just inside the aft cabin, I glued the removed fabric to a piece of 1/4" ply, then screwed it into place, using small screws in lieu of the staples in the cover trim around the edge, which had been glued to the fabric. A larger area might prove a challenge for this technique.

Re: tri cabin wiper motor grounding

Posted: Sun Jan 03, 2021 11:24 am
by rbcool
This was the very 1st problem I discovered on my '87 Tri...... of course while out fishing in Very heavy rain!
This is the reason I joined this forum. Seems like within an hour someone told me they were grounded to the windshield frame.
At the bottom of the port side frame, directly across from helm, I drilled a small hole right next to the frame (inside) then attached a 4' piece of #10 wire to the frame screw next to the hole. It was easy to fish the wire over to the helm since under that section is the china cabinet. I then brought it up into the helm wiring area and attached it to the ground bus.
I put a small stainless clamshell over the wire coming from the frame and you can't tell what's under it.... looks great.
All 3 wipers and washers have worked perfect since (10 yrs)

Re: tri cabin wiper motor grounding

Posted: Fri Jan 22, 2021 3:52 pm
by swampman
I haven't got to it yet, but im pretty determined i want to fix the original problem as opposed to a "work around " fix.
Years of work around fixes are exactly what turns an otherwise well kept boat into a hacked up mess.

Re: tri cabin wiper motor grounding

Posted: Wed May 19, 2021 2:10 pm
by swampman
as an update in case anyone else has this issue , the ground wire is attached to the windshield frame mount bolt on the port side and can be accessed by dropping the removable panel on the headliner . the wire still appeared to be tight and the issue was where the stud or bolt comes thru the frame. i loosened the wire and wiggled the stud a fair bit to regain continuity to the frame , then reinstalled wire and tightened.