Here is a weird story for the forum's edification and my education. I was on the freeway in my new-to-me 1984 manual with electronic overdrive, commenting to my sister (visiting from the other side of the country) how quirky my new little car was. The quirk under discussion at the time was the overdrive, which when activated (well, when the button is pushed) sometimes makes the light come on (and sometimes doesn't), but never actually engages the overdrive. To illustrate the quirk, I pushed the button, demonstrating the lit light and lack of overdrive, then turned it off. About 10 more miles down the road I said we should try it again - and this time the overdrive light corresponded with a sudden change in the engine/transmission noise! Our excitement at the overdrive's sudden appearance quickly turned to dismay, as the car began bucking about and acceleration completely failed. We made it over to the shoulder, and the car wouldn't start again.

Now the car is back at my house, where it still doesn't start. The engine cranks nicely, but never seems to turn over. I'm in the slow process of diagnosing this no-start, beginning with the usual (e.g. spark - yes, fuses - all good, fuel pump - seems to be noisy), but wondered if anyone had ever heard of some kind of catastrophe coinciding with the overdrive trying to engage? Any thoughts would be appreciated - I'm in western Washington state, with no garage, and working in almost freezing rain really stinks.

cheers!

OK, if there's nothing amiss at the fuse panel, I'd be forced to view the OD connection as either a coincidence or the result of some unexpected modifying repair made during its previous 25 year life. So lets just assume coincidence.

An original engine wiring harness with insulation rot can stop an 84 dead. Its AMM can go suddenly. The 25A fuse and its wiring under the hood can cut off the fuel supply if corroded. The wiring to the Hall effect sensor in the distributor is a known trouble spot.

So, spark, fuel, compression.

Compression. You looked at the belt - it wasn't snapped. They don't snap. They just strip teeth way down where you can't see them at the crank pulley. Check to see if it turns when you crank. View the cam through the oil filler cap. A turning belt doesn't guarantee compression; it could have jumped a few teeth, but that's not the most likely event.

Did you say you had spark? If you don't have spark you will in most cases not get fuel either.

Try with the AMM disconnected - it will start then if the AMM has died. Disconnect or reconnect the AMM only with the ignition off.

You mentioned the fuel pump is noisy? Is the tank fairly full; could the tank pump have quit (fuse 5)? The main pump will be noisy if it isn't getting any gas to feed it. Yet the main pump will suck from the tank if it is 3/4 full, even past a dead tank pump or perforated hose in there.




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Art Benstein near Baltimore

Always keep several get well cards on the mantel. If unexpected guests arrive, they'll think you've been sick and unable to clean.

You have probably blown fuse #11 which is for the overdrive, the heated rear window AND the ignition control box on the washer fluid container.

May I suggest you do not use the overdrive or rear window heater until you can trace where the overdrive circuit is shorting to ground.

Duane

"You have probably blown fuse #11 which is for the overdrive, the heated rear window AND the ignition control box on the washer fluid container."

I think we can rule out Fuse 11 as possibly affecting the ignition.

The diagrams show that the Volvo/Chrysler "MPG" control box (pin 2) gets its +12V from the Hot Side or input to fuse 11. The common hot side of fuses 11-12-13 gets +12V from the ignition switch. Meaning the ignition box is not fused.
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Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

Not to flame anybody but what is on paper is not always correct.

Case in point. Duane the ODGuru is the worlds best Volvo mechanic bar none..:>)

The service manual diagrams indicate the side of the fuse where the wire is connected, but not the multiple connections behind the connection point that are fused. Technical illustrators in automotive giants pushing paper do not always draw or copy the correct diagrams. They are there to make it easy to follow.

The Volvo Service Manuals indicate checking fuse 11 for the 83 and 84 model years even though they show the wire coming in on the same side as the ignition feed and appear to not go through the fuse.

Volvo's multiline wiring diagrams do not show a fused sided wire coming out of the fuse panel to the ICU, but do show on the ignition diagram at N3 that power comes from 10sub11. 10 is the fuse panel. So their diagrams both appear to connect and not connect fuse 11 to the ignition.

If one looks at the fuse box cover (if it has not been changed) the fuse designation description and Bentley pg 390-2 indicate fuse 11 is for the ignition systems for 83 and 84.

My long departed 83 with Manual trans once died because I opened the rear hatch with the heated rear window switch on. Even though the wiring diagram indicated to me at that time as Bruce has surmised, it's not fused and I spent a tow and three hours trying to start the vehicle, I finally had the spouse bring the service manual, and replaced an obviously blown fuse 11. Car started. I kept the hatch closed while the the window circuit was on from then on until I changed the hinge harness.

Now my 85 which has the same wiring diagram for the ignition, OD and rear window is not affected by fuse 11 even though the Volvo Service Manual indicates that it is.

Now in this case it may not be as obvious as a blown fuse, but to me when one shifts into OD and the car dies, something somewhere is related. In what manner may turn out to be a PITA to determine.

Eliminate the obvious first.

Duane

"Volvo's multiline wiring diagrams do not show a fused sided wire coming out of the fuse panel to the ICU, but do show on the ignition diagram at N3 that power comes from 10sub11. 10 is the fuse panel."

• Agreed, Duane—except that the (later or model specific) diagram at N3 actually says "10/11IN", which I took to mean INput or "feed side". That's exactly where the older Bosch ICU got it's power, as shown in the earlier diagram in the front. And it would make sense, for wiring harness consistency between models, to use similar circuits where possible.

"So their diagrams both appear to connect and not connect fuse 11 to the ignition."
• Not if you see the earlier (C&D column) diagram as showing the Bosch ignition being "not connected" to fuse 11, but to the input side. And the newer V/C ICU on N3 also being "not connected" to fuse 11 (output), by virtue of the 10/11IN off-page identifier.

I tend to put more faith in the "multiline" diagrams (good term), having often found errors in the Green Book service manuals, as well as fuse panel labeling. I believe those things are written by tech writers early in the game and apparently never updated. Such as the "Fuse 6 - Main Fuel pump" label on LH2.2 cars, when it's not true for U.S. market 240s until 1991.

But this may be the time when the detailed diagrams are wrong, and the high level stuff is right. In any case, it's hard to argue with your closing comment:

"Now in this case it may not be as obvious as a blown fuse, but to me when one shifts into OD and the car dies, something somewhere is related."
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Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

Hi Duane,

You have me with two pair of glasses squinting at the Bentley wiring diagram reproductions again. I saw that reference in N3 - "10/11 IN" thinking I had just ignored the meaning of "IN". It is the same for 83 and 84 on the Bentley pages; my closest full green book WDM is 85 to cover the 84.5 turbo.

I checked again my car-stopping fuse (12 in 83, 13 in 84) in block K5. The Bentley repros seem to have the 83/84 differences drawn there. Now my eyes are sore.
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Art Benstein near Baltimore

An expert is a man that has made all mistakes possible in a narrow field of expertise (Albert Einstein)

Hi Bruce,

I learn something every day, though I shoulda known it. Fuse 11 is a common victim of the frayed OD solenoid wire on top of automatic trannies, without stopping the car. The one that stopped the car on me was fuse 12, when a frayed AC Clutch wire shared it with the fuel system on the 83. That one got moved to fuse 13 on the 84.

You still keeping the Bentley errata? I now have another red mark on 390-2 in the fuse chart.
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Art Benstein near Baltimore

"Body work is just like drywall. Frame it right, hang it right, use less mud. Don't paint until its perfect." -AB

Hey, thanks for the input so far. Here is a little more info...

The car isn't turbocharged. I had to have it towed back to the house - after the freeway death, it hasn't started again.

The timing belt hasn't snapped - I took the cover off this afternoon and took a look. Don't know yet if it jumped around or has lost some teeth, but the starting attempts sound very normal to me (rrr--rrr--rrr).

A further note about the overdrive switch - I did check the wires when I first got the car to make sure they weren't the problem. The wires are at least very well connected to the o/d button.

regards,
-N

I agree with Duane, though you checked the fuses and spark. They often look good along their length, but wind up with a circle cut from the element at their ends. Swap fuse 11 with a new one, make sure the fuse clips are clean, and use a test light or meter to verify the voltage at the inner terminals of 11, 12, and 13, where the fuel system gets its ignition-switched power. The inner terminals are on the fused side of the panel.
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Art Benstein near Baltimore

Those who race through life finish first. (Darrel Hunsbedt)

These are just guesses based on limited information but I think the OD issue is not related to the conking out/no start condition. Guess #1-teeth stripped from -or-broken timing belt (does the cranking sound normal rrr--rrr--rrr or like just spinning rrrrrrrrr?) Guess #2--fuel pump or circuit problem. The OD condition can be caused by multiple probems--chief among them - wire or switch problem at the shifter causing the intermittant indicator lamp -- low fluid or bad solenoid the non-engagement.

Hi there,

My first question is, how you got it home. Under its own power, or towed? Is the '84 turbocharged?
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Art Benstein near Baltimore

Marathon runners with bad footwear suffer the agony of defeat.