Printable Version of Topic

Posted by: Tom Nov 1 2010, 02:25 PM

Looking to get a used relay board for some testing and repair/renovation. Any reason that any one would work on any car?
I have been thinking that a good place for the hot-no start syndrome is the rivited contacts to trace connections in the relay board. Maybe a good cleaning and then soldering these higher current contacts would make the relay board better.?
I think I have read on here that they are all the same, but I'm not sure. What do you think or know?
Thanks,
Tom

Posted by: type47 Nov 1 2010, 02:33 PM

Only difference I know is between -4 and -6 boards. -6 boards are rare enough that you probably won't see any for sale.

Posted by: jmmotorsports Nov 1 2010, 02:35 PM

Tom, I have several from 70 to 76 including a new OEM one from Porsche. The only difference I can see is the newer ones don't have the threaded rod to hold the cover on. Every thing else looks the same.

Jerry

Posted by: underthetire Nov 1 2010, 02:58 PM

Just broke out all the tar on the bottom of mine yesterday. Think it would be super hard to solder unless you could do some kind of acid etch first.

Posted by: Drums66 Nov 1 2010, 04:12 PM

QUOTE(type47 @ Nov 1 2010, 01:33 PM)

Posted by: markb Nov 1 2010, 05:06 PM

QUOTE(type47 @ Nov 1 2010, 01:33 PM)

Posted by: carr914 Nov 1 2010, 05:23 PM

I've got a buy one get one free in the Classifieds for the -4 Variety

And I've got an NOS -6 Board

T.C.

Posted by: Tom Nov 2 2010, 06:52 AM

Thanks for the replys. I have one coming to see what can be done. I'll post results sometime later. I know how difficult these can be to solder. I soldered my fuse holder on the top due to high resistance and I had to wire brush and alcohol scrub it pretty good to get good flow with the solder. Fixed the connection, tho'.
Tom

Posted by: Joe Owensby Nov 3 2010, 07:44 PM

Clean the bottom of the board very well, removing all the gunk. Then use a dremmel tool with wire brush or burr tool to thoroughly clean both the copper trace and the connection that goes to the top. Then, it will solder very easily. Has to be shiny for the solder to stick. Finally, apply a coating to protect the traces again. You can buy commercial potting compount, I think 3M sells this among others. I have read that other people use Silicon seal or other stuff. JoeO

Posted by: underthetire Nov 4 2010, 08:18 AM

Actually, no it really won't solder easy. Problem is the oil from the tar gets under the rivet heads. Thats why I suggested a mild acid etch.

Posted by: Tom Nov 4 2010, 11:04 AM

Guys, thanks for the replys. This WILL be a learning experience to see what works and what doesn't. Still waiting for my test board to arrive. I'll post results when I have them.
Tom

Posted by: DJKnut Nov 4 2010, 11:47 AM

Acid and electronics are a really BAD combination!!! It tends to keep working, corroding everywhere! If you do etch it, then neutralize the acid with a soda dip, then wash it real well with detergent to remove all the foreign stuff. Afterwords (let dry for a couple of days..), I highly recommend spraying it down (both sides..) with LPS-3 which is a water displacer and corrosion inhibiter... It has kept my saltwater boat's electrical equipment trouble free for many years, works great on all the bulb sockets too!! Cheers, Dave

Posted by: Tom Nov 4 2010, 05:41 PM

I will be using rosin core solder for electronics. It won't continue to corrode after use, however, after working on PC board repair in the shipyard, I learned it is always good to clean all soldered areas well before use.
THE KEY to successful soldering is cleanliness! Isopropyl alcohol is a very good cleaning prep for soldering when used with a small stiff bristle brush. Sometimes I have used a pencil eraser to clean difficult areas, then alcohol wash before soldering. If you are working with extremely sensitive electronics, then a cycled bath with certain chemicals would be necessary to ensure no " sneak circuits "have formed. This would be followed by warm air drying for several hours. Then testing.
I don't think we would have to go to those lengths for the relay boards.
Tom

Posted by: swl Nov 5 2010, 03:33 PM

Tom it should be easy to locate the point of resistance with a multimeter. I can offer suggestions if you feel like playing detective.

Posted by: Tom Nov 6 2010, 10:13 AM

Steve,
Sent you a PM. Ha, I joined this club two weeks after you.
Tom