Testing relay boards...., Can you bench test a 914 relay board....??? Options

[second wind]

Hello out there....my car has been dying after getting a good warm up but starts the next morning. The tell tale symptom is that the fuel pump does not run when the stall occurs and even after hours of cooling off it still does not start...but it does in the morning....???
So talk on the street is the relay board is too old to work properly.....the description of 914 LTD's improved and rebuilt relay boards matches the symptoms of my car perfectly so as soon as I scrap up the money I will buy one.....meanwhile I have two spare relay boards and one looks really good. Is there a way to bench test the relay board before I swap the boards ?? These cars sure keep you on your toes and a relay board with fresh soldered connections sure sounds appealing so Brad is holding one for me. So back to the swap out....I hate to go to the effort just to install another faulty board. Look forward and appreciate any and all comments and help....thank you very much!!!!
gg

[Superhawk996]

(IMG:style_emoticons/default/agree.gif) with a couple modifications:

There is nothing magical about the relay board. It is actually from the stone age. Just large copper traces inside a plastic housing that runs continuity from point to point.

1) As a former electronics technician it annoys me to no end to see all the forum threads about electrical troubleshooting where the proposed solutions are simply guess work and parts swapping (Note: not targeting @second wind - just a generalization) I've largely stopped trying to participate in those threads because people refuse to use a schematic and a Digital Multi Meter (DMM). I know it might take some time to learn how to read schematics and/or to use a DMM. The reality is that if you're going to play with 50 year old cars, you're going to have to learn sooner or later. Google & YouTube are your friend for learning how to read schematics and to use a DMM. Otherwise:

a)You're going to pay $$ to someone skilled enough to use a DMM, a schematic, and then to troubleshoot properly.
b)You're going to waste $$ on needless parts and parts swapping
c) You're going to pay some other "mechanic" to do the parts swapping and guessing for you which is the worst possible outcome both for time and $$.

2) These boards do have a lot of swagged connections within them as 914 LTD states on the website. However, swagging is a form of crimping that is more reliable than soldering per Auto Industry, Aerospace, and NASA white papers. Yes, it is possible that a swagged connection could be come loose, but it is less likely than one of the soldered connections within the relay board with a cold solder joint, and/or a stress cracked solder joint. Sure you can solder every swagged connector as belt and suspenders, but in reality you're more likely to have a bad solder connection due to a dirty board and/or improper fluxing over the swagged connection than a bad swagged connection itself. If acid core flux is used to do the soldering, you'll have a long term corrosion source on the board itself if the flux is not completely removed. NOTE: I'm not trying to tear down the 914 LTD relay board. I understand why he's offering this as a service as there are bad boards out there with corroded traces, traces screwed up form DAPO's shooting long regulator screw across traces creating shorts, bad potting, and even some with stressed solder joints and/or swagged connections due to corrosion or improper handling over time. I understand why the solder belt and suspenders approach holds appeal and it's not likely to hurt anything. Having de-potted a couple boards myself, his pricing is fair, so is @914sixers for restored boards. It takes a lot of labor to remove the potting, continuity check, redo these boards with new potting

If you really want to do the whole bench test routine, do as @914sixer suggests and simply test all connections for continuity at room temperature.

If you want to go the next level and really think heat cycling is your problem, warm the board in your oven to about 150F - 200F then test continuity again. If you have the board de-potted, you could also use a heat gun (carefully) at the specific swagged connections of interest.

Going back to point #1, you don't have to test all continuity across the whole board, just those traces that handle the fuel pump, the ignition coil, the tachometer (which is also connected to the coil), and the ECU feeds (if fuel injected),

In OP you don't mention if you've already ruled out the relay itself, and whether you've verified the integrity and power feeds to the components (coil, pump, ECU) itself both hot and cold. I'd do that before jumping to swapping relay boards.

[raynekat]

(IMG:style_emoticons/default/agree.gif) with a couple modifications:

There is nothing magical about the relay board. It is actually from the stone age. Just large copper traces inside a plastic housing that runs continuity from point to point.

This is so true.
Get a multimeter and a wiring schematic for the relay board and have at it.

On my 914-6 relay board, I found two (2) of the copper traces that had a break in them that needed a bit of solder and all was good.
If you are seeing sporadic stuff happening during the day, there's a good chance that a trace has a small break in it that shows itself from time to time.

Definitely not rocket science testing this relay board with a multimeter.