Fixed the 740...but headlights inop!

It didn't run *not* because it was being flooded out by too much gas.
The mechanic who had worked on it had the camshaft set so that with
#1 piston a TDC, the rotor was on #3 sparkplug! I reinstalled the fuel
rail, reset the camshaft timing, and it fired right up, runs fine!
Also I found the real cause of what he was trying to fix by
replacing a $50 fuel pump relay.....the problem of it suddenly dying
intermittently. I looked the fuse panel over, and the fuse in #1
position for the fuel pump power was totally shot! It overheated
sometime in the past...the plastic around the socket opening melted,
the two fuse contacts were black and totally loosened. All it would
take is a bump and the fuel pump would shut down with the fuse that
loose. So that was an easy fix, I just broke out the bad/burned fuse
socket and put a pigtail fuse holder in its place.

Now the problem is that the low beam headlights do not work. The
high beams will work if you pull the stalk backward, but they do not
latch on, so they are only on as long as the stalk is held rearward.
The mechanic was working on the fuse/relay panel when he replaced
the fuel pump relay. So I think it is something he induced. I noticed
that there is one relay base that has (I think) four wires going to
it---identified as relay F in Haynes manual. The base is there, but
there is no relay. But Haynes manual says it is for front fog lights
which the car doesn't have. So hopefully the Haynes manual is right
and that has nothing to do with the problem.

There is a red round relay (A) which I believe is the bulb failure
sense relay for the low beam lights. At least the Chilton 90-98 manual
shows only the low beam lights powered through it. So this is a
possible cause I guess. The Haynes manual says that relay K on the
front row is the central locking/main lighting relay.....maybe it is
feeding low beam power ? Unfortunately I don't have either relay.
Advice?

 

Wow, I would not let that mechanic anywhere near my car again if I were
you, he missed checking some of the most obvious things, wasted time
doing other things, and then failed to align the camshaft correctly when
putting it back together. It takes a special kind of incompetence to do
that.

The red can is the bulb failure sensor, you could pop the cover and see
how the soldering on the circuit boards looks. Fuel pump relays can
easily be fixed this same way.

 

James:


Also, to make matters even worse, when it went into this mechanics
shop it had a working radio, a very nice one. When I got car to my
house, the plug-in front had disappeared. Are replacement front
panels hard to get? The mechanic is asking what brand of radio it is
as he has a few panels in his office. But....the brand name was on the
front panel! Now I have to figure out how to get the radio itself
pulled out so I can look for model/ p/n. Don't have a clue. There must
be some sort of fasteners or clips accessible from the bottom...while
I have the fuse/relay panel out to fix headlights.


THe other issue perhaps you can help with is that I found a
two-contact connector right ckose to the block under intake manifold
just dangling! It comes out of a harness that passes by IAC
control valve, going on towards the block, and I think this same
harness goes to the two temp sensors under the intake manifold. There
isn't a code for knock sensor being set, but I think this engine is
supposed to have one....but I don't find a sensor underneath the
intake manifold that is not plugged in. From the Chilton manual, it
is positioned about in the area where the knock sensor should be, but
I've never seen it. I think it mounts with one large bolt.

Thanks, Geronimo

 

Nope its not knock sensor connector, looked at it again in good
daylight, and knock sensor is there, and has a connector on it. So I
don't know what the disconnected connector could be for.

 

iirc, mine has such a disconnected socket as well. Could be a
multi-model harness with an unused connector for your car.

I would make a complaint with the BBB, auto service bureau or such
about that mechanic. He should have been able to HEAR that the timing
was off as soon as you pulled it in. And now the radio front is
missing and he just HAPPENS to have extras in his office!?!?!?

Use an ohm meter and check to see if the switch is sending voltage to
the headlights and then trace the problem from there. maybe the
mechanic switched your headlight bulbs- check to see that the are good
and connected before driving yourself crazy! AGAIN!!

;-)
__ __
Randy & \ \/ /alerie's
\__/olvos
'90 245 Estate - '93 965 Estate
"Shelby" & "Kate"

 

Is this an aftermarket radio? Usually they come with some special
release tools to remove it from the sleeve. Without those, getting it
out will be difficult.

That does sound like it could be the knock sensor wire. The sensor is a
round puck that should be bolted to the block in that general area.

 

I think it is an aftermarket radio, but it fits in the dash like OEM.
Felt around underneath the radio, but couldn't see how to release it,
so I am just hosed as far as radio.

I looked underneath intake manifold in better light and the knock
sensor is there. Randy G. says he also has an unused similar connector
on his 740, so I guess it is not supposed to be connected, its just
unused.

I swapped J and K 4-terminal relays, and then the headlights
worked, so I have a bad main power relay. Simple fix.
Now all I have to do is replace smashed RH turn/ marker lens, get a
set of new tires, fix A/C and its good to go for another 100K. ;-)

Thanks, Geronimo

 

Well you can remove the whole assembly to get to it that way, I forget
how I did that now, does anyone know if this car has the same style
radio cubby as my '87?

 

James: well the radio is a small issue. The speedometer doesn't
work, the sender in the differential probably is shot. For some
months it was intmt before dying altogether. I did check the
connector to it and it was OK, no broken wires. This is a $90 part
new from RockAuto.com.... A bit steep, so you wouldn't have saved that
from the Volvo you parted out, did you? The local junkyards never seem
to have 740 parts....I wonder if the 92 240s (if there was a 240 that
year) and the 940s used the same sender? Thanks, Geronimo

 

Actually I might be barking up wrong tree entirely on the speedo
sensor. Driving it around today I noticed that the odometer is still
working. I would think that pulses from the same sender in
differential are driving the odometer also, so if it still works, it
would have to be the speedometer itself that has stopped working.
Right?

 

Wow...given the string of disasters that guy has caused I wouldn't let
him within 100 feet of the car. You may want to look into having an
independent evaluation done and consider bring suit!

For electrical issues I would get a copy of the Volvo manual for your
car.

 

I've never seen or heard of one of those senders failing in a Volvo,
*ever*. In theory it could happen, but that would be the absolute last
place I looked. Start by checking the fuse for the instruments, then
look at the speedo itself and the wire to the sender.

 

Bingo, you've got a problem in the speedo itself, solder joints on these
are notorious for being bad.

 

Concerning the speedo sender: I think I am barking up the wrong tree
---on second thought---- as I noticed today that the odometer is still
running, just the speedometer needle is always showing zero now. I am
thinking there is only one signal drving both odometer and
speedometer....is that right?

 

I found an entire 92 740 turbo inst cluster for $37.00 on
eBay....maybe it will fix the turbo boost and temp gauge as well!

Thanks, geronimo

 

The other question I have is what do you do when the little ball-joint
plastic mount/support ends break that hold the headlight assemblies?

For now I have two bungees installed on the healdlamp sockets so that
the headlights aren't completely loose, but of course they cannot be
adjusted normally.

 

The turbo boost guage is mechanical, if it isn't working the hose popped
off or split somewhere.

 

You replace the broken parts...

 

Yea, I kinda thought that much myself ;-)

I guess what I was getting at is if the headlight mounts can be
obtained from some supplier, or if that is something that has to be
scrounged from a salvage yard. On the other hand, bungee cords are
cheap and will probably last 50K miles ;-) I can also tell someone
truthfully that the old car is being held together with rubber bands
;-)

 

Dunno, I'd start by calling the parts dept of a local dealer to find out.