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/av-943.gif) at Ian's perfect description of what happens when the random parts swapping occurs . Truer words never written (IMG:style_emoticons/default/type.gif)

I'm happy to support you in the endeavor to find root cause.

The fastest method of troubleshooting almost anything is the half split method. Know the system you're working with. Find a way to divide it in half, part A & part B Is the problem in Part A? No? Then it must be in part B.

Now divide part B in half. Let's call them parts C & D. Problem not in C? If so, it must be in D. You get the idea.

In the case of your "suspected" issue of not having fuel pressure, the relay board is a perfect place to half split the system.

Let's divide it as power into the board as part A, and power out of the board as part B.

In your case, the intermittent nature of the problem when it's hot makes things a bit trickier but at least we know that you can duplicate the problem when it's hot. That's a great start.

So let's start by verifying (with Schematic & DMM) what all power conditions are when its running cold. Both on Part A (power input) side of the board, and part B (power output)

Then warm it up until you can duplicate your no-run condition.

Then recheck Part A (power into the board) -- if good when hot -- your problem isn't on that side of the system. If not good, then we work to figure out why it changed and where root cause is in Part A.

If the power output in Part B is not good when hot, we'll work our way through the Part B side until you find it.

Bottom line, you can do this, and I'll help in anyway possible, but it needs to be done logically, and methodically. (IMG:style_emoticons/default/grouphug.gif)