Rebuilt My Turn Signal Relay

1982911SCTarga · 06-02-2013, 09:02 AM

My turn signal relay on my Targa has been intermittent -- working sometimes and not at all at other times.

These original Hella relays can be easily disassembled and inspected with a thin-bladed tool or small screwdriver. I cleaned the contacts with 1500 sandpaper, with no joy and continued intermittent operation. The circuit components all looked fine. There are, however, two 47 microfarad capacitors on the board. I bought replacements for both of those at Radio Shack for $3 and change.

Replacing the capacitors isn't a difficult task if you're confident in your soldering skills. Anyway, a few minutes of work and my original relay is flashing like it should.

Brian

Joe Bob · Joe Bob's Garage

I applaud your successful repair. Most would toss and buy a new one. Good on ya.

timmy2 · timmy2's Garage

Good job. Pictures?

AC78 · 06-02-2013, 01:04 PM

Quote:

I applaud your successful repair. Most would toss and buy a new one. Good on ya.

I DID recently toss in for the genuine part for a hefty $107!! Wish I new about this option earlier

Joe Bob · Joe Bob's Garage

Oz tax? They are like 35USD....

pete3799 · pete3799's Garage

Early SC relays are in the 60.00 range i think ( can't even find a listing for them anymore.....Wayne?). Good work on the repair.

AC78 · 06-02-2013, 02:12 PM

Quote:

Oz tax? They are like 35USD....

More like Porsche tax. We get fleeced pretty good down here. They charge what the market will bear.

1982911SCTarga · 06-03-2013, 07:10 AM

My local auto parts store quoted something like $58 and it was a special order item. It was enough money and hassle to encourage me take a second look at repairing the non-working original relay.

Brian

1982911SCTarga · 06-04-2013, 06:05 AM

I should add that when replacing capacitors on a circuit board, always make a note of the polarity (positive and negative poles).

Brian

euro911sc · euro911sc's Garage

How did you know it was the caps? I had to replace mine last year... but I still have the original one. Might be worth screwing with...

1982911SCTarga · 06-04-2013, 08:15 AM

I didn't. Replacing the capacitors was an informed guess. The relay coil and the resistors on the board all had continuity. Capacitors are difficult to test without specialized gear, but they do fail/become flaky over time. For $3, I guessed correctly. And I wasn't out much if the hunch was wrong.

Brian

HawgRyder · HawgRyder's Garage

Side note...when replacing capacitors...check the operating voltage of the old one...replace with same capacity but higher voltage rating if you can.
Also...there are caps with bi-direction capability if you cannot determine the polarity of the old one...although a simple voltage check will tell you which side is the positive.
There is also the operating temperature to consider....a gold rating of +80C is about normal...but there are caps with +120C available.
The higher limits for the cap will extend the life expectancy.
Bob

T77911S · 06-04-2013, 05:40 PM

do you think it may have just been a bad solder joint and replacing the caps just fixed the joint?
just asking because i see a lot of this problem.

dshepp806 · dshepp806's Garage

I you removed the ORIGINAL electrolytic caps (check the manufacture date stamp), then you surely made a very smart move,..very cheap fix. that electrolytic isn't like wine, for sure. They, eventually, need replacing. A higher voltage rated cap would be a smart move, as well.

Good work!

Doyle

T77911S · 06-05-2013, 03:24 AM

are they electrolytic or ceramic caps? the electrolytic caps WILL "dry" up and go bad.
they were a nightmare when we had an old military voice switch here back in the early 90's. i still have a drawer full of them.
electrolytic caps are generaly polarity sensitive as said. if there is a band or crimp, that is positive. there may be an arrow pointing to negative. if nothing, dont worry about it.
this is why CD units go bad and still have the whine, the large electrolytic cap goes bad.

1982911SCTarga · 06-05-2013, 06:22 AM

Quote:

do you think it may have just been a bad solder joint and replacing the caps just fixed the joint?
just asking because i see a lot of this problem.

No, this is a small, very simple circuit board, and you can easily check it for cold joints, etc. I also went around it checking continuity. Process of elimination.

The old capacitors lasted 31 years, and the relay lives on...

Brian