The car will not start. I checked for sparks:OK. Then I checked for fuel pumps operation when bridging terminal 30 with 87/2 in relay connector (relay is now diconnected): Both pumps stayed silent. Then I checked for voltage at terminal 30: There is battery voltage. I tried to energize the main fuel pump by connecting directly (bypassing) to its connecion under the rear seat: It worked. That tells me that the pumps are OK.
Then, I tried to energize a spare pump I fetched in my box of miscellaneous parts: I connected it to terminal 30 with the other post to ground: Nothing happened. I know that the test pump is good.
Can someone explain to me how I can get voltage at terminal 30 but without current flowing through it?
Any other suggestions on what to check?

Thanks

Richard

The circuit from 87/2 goes thru a 4-pin connector (under glove box area?), then to the hot side (left contact ) for fuse 4 before it goes on to the main pump. Since the tank pump doesn't run either, the power is probably not getting as far as fuse 4.

So look for that 4-pin plug. It will have the Y/R pump wire feeding thru, plus the Red/Black wire from Ignition Switch to Fuel Relay 85 and ECU #18.
--
Bruce Young,
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

sounds like you used a test light. a meter will tell you if it's 9.5 or 12.5 volts, both of which will light a light. the 30 power comes straight from the battery through the fuse holder next to it. anything loose will pull the power down. good luck, chuck.

Thanks for the reply.

I used a digital multimeter. It showed battery voltage i.e.: 12.4 Volts

what's the meter say at the fuel pump while the relay is jumped. backtrack until you find 12.4 again. good luck, chuck.

If you mean to connect the meter in parralel with the test pump: I got, maybe, 1 Volt. Anyway, I found out what was wrong and YOU gave me the hint when you wrote that anything loose between the battery and the terminal 30 (in main relay connector) will drive the power down. It was verry basic and required simple common sense logic: BAD CONNECTION AT THE BATTERY POSITIVE POST. How about that! As my wife said to me after I spent 6 hours trying to locate the problem: "Maybe you had spark in the cylinders but there was not much spark in your brain!".
In my defense, considering the bad connection to the positive post, I would love to have someone explaining to me how you can get enough power to crank an engine up but not enough power to get the two fuel pumps running!.

Thank you for every one who gave input.

Richard

Not sure if your car has this (later ones do), but look for a 25-amp blade-style fuse under the hood, along the left fender between battery and coil. It's in a fuse holder and it's notorious for corroding and overheating. Check to see if you have one, and check its condition. If there's any sign of corrosion or overheating, replace it - about $5 from NAPA. Just get one rated for 25a minimum.

Yes I know about this fuse. Few years ago, I had to replaced not only the fuse but the fuse holder as well. The present fuse is working.

Thanks