1990 740 volvo wagon
Was running fine then all electric left. Not even 4 way flashers worked. Then a faint tink sound and all was back Ran fine again then that tink sound and all electric gone.
Is their a circut breaker working someware? Now all electric is gone and staying dead.[]

 

Check the connections at the battery and starter and alternator.

 

WELL
I have been pulling wrenches for 35 years so when it quit on me in town I had some time to go over all the stuff I could think of.
This is the first volvo I have owned so a lot of the electrical is new stuff to me. I did check the bat (remove& replace the well greased terminals) .
I also checked the alt connections, And all Other connections under the hood.
I then took apart some of the dash and found and checked the fuses and relays as best I could.
The entire fuse panel seems to be dead no elect any where.
This car started acting up before I went to town . It would start fine and run until I put to much of a load on the electrical system, Run fan on high turn on lights = faint tink and all electric gone.
Sounded like a turn signal flasher clicking one time.
After it had time to cool down another tink can be herd and all the juice comes back .
The tink seemed to be coming from the fuse panel aria but it might have been more to the right or perhaps on the other side of the fire wall.
From all my tests I think their is some sort of power relay which when hot will chop power to the entire car. The 4 ways won't even come on.
This has me mystified as I am not familiar with what all bosh and volvo have done to this car.
What ever this is, it has clicked it's last and now must be found, as the car has no electric at all .
If you have no ideas as to where to start my search I will start to follow the hot wire with my test light and work my way back from the engine compartment .
With all the wires and looms I will be their for quite some time.
I do have a manual coming from amazon but it is in the mail.
If you have any suggestions I would like to here them. Thanks Much
Mike

 

Would the on board computer kill all power to the car if it went out ?
Do the on board computers have a reputation for on again off again failure?

 

I had a similar problem on my 89 240. The first thing you want to do is pull out all of the fuses and clean the brass fuse connections very well with steel wool. Then replace any fuse that looks questionable (I just went ahead and replaced all of them with brand new ones). Next check your alternator belts, make sure that they are nice and snug and in good condition. Next check the connections at the back of the alternator (including the ground wire and "tickle" wire that goes to the dash light) if any of the wires are corroded or cracked, you might want to replace them. I had a cracked ground wire and replaced it. Next you might want to throw the battery on a charger and see if it will hold a charge. We had a cold snap and my old battery quickly died. It would work fine sometimes then it would just cut completly out. I also re-soldered the main battery post connector as it was pretty corroded and wire was hanging out of it. There are so many electronic components that need constant voltage on the fuel injected Volvos that if the voltage dips, everything shuts down. Not like the cars of old that would run just on alternator power, or have dim headlights etc. The sound that you heard was most likley relays tripping. Relays are set by voltage and when it is gone, they trip and/or try to reset by residule voltage. I also had a wire for the rear seatbelt warning light that was shorting out on the metal frame of the armrest. The darn thing was blowing fuses and it was connected to the fuse that ran the fuel pump, so it would start and then quickly die. Just some food for thought.

 

My '89 740 Turbo has been doing the same thing lately. The alternator is starting to go out on mine.

 

I towed the car home and put the charger on the bat . The charger told me the bat. was ok but I left it trickle all day. No change.
The car is still dead. interior lights, gages,4ways, everything inside has no electric.
I did check under the hood their is power at the alt. thats about as far as I was able to determine as it's cold out their.
Tomorrow I will push it into the garage and do some more checking.
I have just bought this car and have replaced the struts shocks exhaust and now this .It's starting to look like a money pit . Perhaps all I have herd about Volvo is not true.
Starting to think I should have gotten a Toyota LOL
Thanks for your input so far no go .

 

There is no main relay that controls voltage to the entire car. The electrical part of the ignition switch is known to go bad, I have replaced 2 in a little over 500k. Do you know how to do voltage drop testing ? You may have a bad battery cable. See if you can get starter to turn by putting 12v to the small connector on starter. If it cranks I suspect ign switch, if it doesn't bad connection or bad cable. Voltage drop test will tell you where.

 

Yes the starter will crank if I jump the solenoid however I can find no power inside the cab whatsoever. I have been searching with my test light and so far no dice.
The fuse panel is completely dead . This panel should be fed by a positive wire yet no power . Someone on another forum said to check behind the glove box for a cluster of wires and clean them . I will tackle that tomorrow when I get the car in out of the cold. I have the entire dash pulled apart testing all sorts of things people have suggested so far all in vaine.
It's going to take me a whole day to put this car back together once I find the problem ..LOL
Thanks

 

today I have checked the cluster of wires behind the glove box ( what a job to get to them)
I find no power on any of these wires.
It looks like I will need to get out the razer blade and start to open up the looms under the hood.
This isn't going to be a lot of fun as they run all over the compartment. Yikes!! what a bugger.
I had hoped someone would point me in the proper direction but so far no go .
I will keep checking in just in case someone out their is in the know as to where I should be concentrating my efforts.
Thanks