This is a 1983 240 turbo that stalled while I was driving out of a parking lot. Turned over, but I couldn't hear the fuel pump buzz. I thought it might be a fuel pump relay problem and a simple fix, so replaced the relay with a new spare when I got the car home. That didn't fix it. I checked the BB archives and Bentley, and did a bit of troubleshooting.

1. Fuses, 5,7, and 13 are all good.

2. I jumped left connectors for fuses 5 and 7, and the car started right up. So, it looks like the fuel pump relay circuit is the problem.

3. I then disconnected the relay and checked power at the connector positions for 30 and 15 following Bentley, although I'm not sure if I did that right. For position 30, I connected it to either side of fuse 7 using an indicator light, and lit up the indicator.

4. I did the same thing with position 15 of the relay connector and fuse 13 and got no voltage. On this one, especially, I'm not sure if I should have gone from position 15 of the relay connector to ground or somewhere else. Right now I'm stuck. I'm wondering if it is in the circuit for position 15 and ignition switch and/or coil, but am just guessing. Wires connected the coil at 1 and 15 look OK.

I can use any help offered. Would especially be interested to know if I checked the relay circuits correctly and what to do next.

Guri

First, a thanks to all who responded, especially lucid who coached me through learning the fuel pump relay circuits and responded to a number of my updates. What I ended up doing was rechecking the voltage at the relay connector using a multimeter, instead of the test light I was using before. This time all had voltage, but connection 30 read only 3.6V when there was 12V at fuse 7. I started to trace the lead to 30 back to fuse 7 to look for the fault and found, instead, that the wire went through the firewall, directly to the battery (+) terminal with an in-line fuse near the battery, by-passing the fuse 7 altogether. The fuse was in one of those holders without a cover and was badly corroded. There was enough of a connection to light up the test light, but not enough to turn on the pumps. So, went to my discount auto store, bought a new in-line holder and 15 amp fuse, and installed them; the car started right up and ran beautifully. And both of my fuel pump relays tested OK. I'm the second owner of this car and bought it about three years ago. It appears the wiring on this car has been modified, and that's the twist and lesson. All the advice and manuals like Bentley are based on a stock setup, but I know I shouldn't assume that on a 23 year old car without good maintenance records. The expertise on Brickboard was invaluable for me, as has been the case in numerous previous occasions, and gave me the clues needed. I'll think some more on the post from wolfi on the coil and what fuse 7 is connected to. Thanks again.

--Guri

if you got a high voltage shock maybe your coil or coil wire is leaking...the relay connector should have only 12vdc. HV leak from coil to coil's hot feed line could also harm the computer if it is on same circuit. Later model coils (those that still use coil) have added a heavy rubber shoe on hightension of coil for extra protection. Check to see if a spark jumps from center to either of the coil posts (with the computer disconnected).

Guri was checking the coil primary white/red wire for the required pulses at the turbo (K-jet) fuel relay. He learned that when the primary field collapses, that wire carries a good jolt.

He definitely had a "learning experience", finding that his K-jet relay is being fed by an LH type blade fuse instead of #7 fuse.
--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

The other learning experience was coming away with a better understanding of the circuitry for the FPR. Thanks again for your help, Bruce.

Guri

Guri,

You checked the right terminals, but to detect voltage presence, I always ground one meter or test light connection.

Terminal 30 should always be hot from fuse #7. That's the voltage that the relay passes on to all the FI stuff (Pumps, etc.) when the relay gets "picked".

Terminal 15 should have voltage (from fuse #13) as soon as the Key is turned on. This goes to the plus side of the relay coil, which is already grounded by terminal 31.

BUT the coil does NOT get energized until it "feels" Ignition Pulses at terminal 31b. These pulses come on the White-Red wire from Ignition Coil terminal #1. If they are there when cranking. I think a test light will glow dimly.

(NOTE: Some K-jet relays will "buzz the pumps" for a second at Key ON. But I'm not sure if this is a reliable indication of a good relay.)
--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

Can I test it by sticking one end of the tester in the 31b connection of the FPR connector, the other to ground, and cranking? Or testing it at the connection on the coil? Thanks for the information.

"Can I test it by sticking one end of the tester in the 31b connection of the FPR connector, the other to ground, and cranking? Or testing it at the connection on the coil?"

Yes test at the relay first. You can leave the relay connected and "back-probe" with your test light where the white-red wire goes into the plug. I now believe the light should "flash" (rather than glow dimly) if coil pulses are there.

If you don't get any pulses at the relay plug, then check at the coil. Sometimes just taking the coil connectors off and on a few times will rub off any oxidation or corrosion.
--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

Here's what I did tonight. Removed and cleaned connectors at the coil; applied a little dielectric grease before reconnecting. Then went to the FPR relay to check 31b. I couldn't get a signal by sticking the probe on the test light into the back of the connector, so I disconnected the relay and inserted the probe in the plug side. I didn't tell whether I got a flash or dim glow, but I did get an H*** of jolt when I cranked it. I was holding on to the metal housing of the test light at the time to keep in place and dropped it. My arm still tingles; must have given my nervous system a test while I was at it. I guess that must mean that 31b got power from the coil. I also tested the ground position of the FPR connector at 31 and got power to the test light when I connected the other end to left side of fuse 7. The only circuit that I haven't been able to get power from is the one connected to position 15 on the FPR connector with ignition switch on. Does this mean that I've traced it to the circuit to the ignition switch or the switch itself? And, if so, what next? From the wiring diagram it looks like 15 on the FPR connects to fuse 13 and goes to the ignition switch if I am reading it correctly.

--Guri

"Does this mean that I've traced it to the circuit to the ignition switch or the switch itself? And, if so, what next? From the wiring diagram it looks like 15 on the FPR connects to fuse 13 and goes to the ignition switch if I am reading it correctly."

I find it easier to think of the voltage as going in search of a ground. So it goes from the battery to the ignition switch to fuse 13 to relay 15 to the relay coil to ground at relay 31.

If you don't have it at relay 15, my money is on fuse 13 -- or possibly weak, corroded fuse 13 contacts. It wouldn't be the first time that fuse has caused a no start. It's not common by any means, but it does happen.
I'd say you have it just about nailed.
--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

Last night, I checked fuse 13 and it is OK. I also checked the fuse connector before and after the fuse, and I get power to the light with the key on. The last thing I did before quitting was to put the test light between 15 and 31 on the FPR connector and, now, I get voltage there. So, it looks like all the circuits for the FPR are OK. Bentley states to check/replace the ignition switch at this point. I jumped across the left side of fuse 5 and 7 again, just to verify pumps, and the pumps come on and the car starts right up with a turn of the ignition switch. So, switch is OK as well? Back to square one? Could it be that my new relay is a lemon?

"The last thing I did before quitting was to put the test light between 15 and 31 on the FPR connector and, now, I get voltage there. So, it looks like all the circuits for the FPR are OK."
• I agree. Don't know why you didn't get voltage at relay 15 before. Maybe testlight had a bad ground connection.

"Bentley states to check/replace the ignition switch at this point."
• I think that Bentley NOTE is screwed up. It says if you have power at terminal 30 of the ignition switch...the switch is faulty???
That makes no sense to me. Switch terminal 30 is where the relay 15 power comes from:
Ign. Sw.30=>Fuse 13=>Relay 15. You must have power at Sw terminal 30.

"I jumped across the left side of fuse 5 and 7 again, just to verify pumps, and the pumps come on and the car starts right up with a turn of the ignition switch. So, switch is OK as well?"
• Sure — it must be if you saw voltage at fuse 13 and relay 15.

Back to square one? Could it be that my new relay is a lemon?"
• I'd have to say yes to that, since you have voltage at 15, pulses at 31b, and a ground at 31. With those conditions, the relay should "pick" — and connect the input (fuse 7) voltage on terminal 30, to the output terminals 87 and 87b.
--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

Thanks. Will check when I get home from work today. --Guri

The 1983 and 1984 240s have two relays in there, later models have only one, and it's a unique one.

Did you replace both relays? Check the connector bases for overheating or water damage?

Just a quick answer. Past my bedtime now.

Good Luck,

Bob

:>)

Two relays? I changed the green one, which should be the fuel pump relay. Would appreciate more information on this.

Guri

bc was thinking you had a non turbo