Help! I crossed the cables while jumping a dead battery

GADAWGFAN · Post by **GADAWGFAN** » 29 Jan 2006, 17:14

I accidentally put "red to black" and "black to red" while jumping a dead battery on my 1995 Volvo 850 Turbo. The cables were connected for 30 seconds before I realized what had happended.
Now when I try to crank the car my starter just turns over without ever hitting. I had a local repair guy look at it and he says that the "brain" is likely ruined.
I have located the computers and my car has a three slot holder but it had only two computer componets; the driver side slot was empty. In the passenger side slot there was a device that had a large "5.3" on it. It also has a series of numbers on it.
In the middle slot there is a device that has a large "8.2" on it. It also has a series of numbers.

Is it possible that there is someway to discover which of these devices control the ability to start the car?

Post by **MadeInJapan** » 29 Jan 2006, 17:49

The one that says Bosch on it is your ECU which is the computer to manage the Engine, and will have to do with starting. The other one should say Aisin or Aisin Warner on it...this is your transmission computer. There is an empty slot there on purpose. Before you go to the hassle of buying another computer, make sure you didn't knock out fuses and relays. Isn't that what fuses are for anyway? Look in the fuse box under your hood and test all of the fuses one by one with an Ohm reader. Replace the bad ones. This in itself may bring your car back to life. Of course, you could have knocked out your starter or other things....Just don't assume your ECU was fried, right off the bat, although possible. If by chance you do need a new ECU, then do a search on eBay for them. Just search for Volvo ECU and 850 and check the "titles and descriptions." There are currently over 30 listed and some are not very expensive. You are lucky that the 850 ECU's are fairly plentiful. Good luck and let us know how things go.

By the way, if you do come to the conclusion that you need a new ECU, post back here. All of the numbers on it are pretty much meaningless. It's really only 3 numbers that make a difference....and we'll need to show you where they are and how to match up a replacement ECU to be an exact fit with your current one (you don't want to buy the wrong one...it won't work).

Guest · Post by **Guest** » 30 Jan 2006, 12:15

What a timely thread this is. I go to fire up the old girl this morning after sitting for 3 days over the weekend and it cranks OK but doesn't start. I then jump with the other car and she cranks but doesn't start. Moist and foggy outside, around 32F. Cables correct, reds to positive, blacks to negative. I agree with poster above, confirm that you did fry something before ripping things out. Will jump this afternoon again after letting sit for about 6 hours but my question is this. I had this trouble once or twice before where I hadn't started in a few days. It's been warm and cold last month (5 - 40F in morning) or so and I'm in year 3+ of the battery so that may be it but while I try jumping later should I:

Do I pump the gas pedal at all before I try to start? If so, how many times? (normally I don't/don't have to, EFI and all)

Pump it during starting attemp?

Hold gas pedal down while starting?

Other?

*Slaps self on side of head, reminds self, for older cars, especially in winter, start car every other day at least!* '94 850 n/a auto

Post by **MadeInJapan** » 30 Jan 2006, 18:00

Volvo's have a self limiting device that keeps it from flooding from what I understand. Hold the pedal to the metal and keep cranking...as long as 1 minute straight if this is what it takes. I've heard this scenario several times on other boards.

Guest · Post by **Guest** » 31 Jan 2006, 08:12

EXACTLY the kind of answer I'm looking for mij. I finally remembered that after I got back with the new (used) Acura that the wife now has, (I don't mind so much breaking down but want to spare her) that it was slightly moved in the driveway. Ask the wife, "Uh did you use the car? I thought you told me you didn't need to go out or else I would have moved the Acura and took the Volvo instead."

The running joke is every time she uses the volvo, I end up with a new problem within 2 days of driving it again. IOW, the joke's always on me... She says, "Oh, yeah, I moved it (so our daughter) could shoot baskets 'cause no bb practice today. I said, "Uh oh, that means you moved it twice in about 30-45 mins. to move it and put it back without letting it run for at least 5 minutes." (winter with cold and warm days a lot lately) She says, "Yep." And the rest is history. AHHHHHHHH!!!!!!!!!!

I pulled the battery and have it on a 3 Amps slow charge battery charger machine (a really old one borrowed from my neighbor) but noticed the date is 8/2000. I thought, woah, much older than I realized but it does say 24/84 ( 2 year free replacement warranty and 7 year total warranty), so I don't hold out much hope.

When jumping yesterday the cranking got worse even though I was jumping hooked up to a running car. Hope I did'nt F*ck something else up.

Anyway, I will now put the "pedal to the medal" when I put the battery back in after a 2-days slow charge and give it one long cranking shot. I did that yesterday once and she almost fired up. If she don't start this time, have to decide to get a new ~$60 battery or put in the selling paper ad, "You must get this thing out of the driveway yourself."

Man, I'm in a bad mood today, sorry... Love/hate relationship with this car but my Japanese cars have spoiled me and this thing is simply tooo much work to keep going. Bad seat backs, unopenable gloveboxes, new struts, 3-month required ETM cleaning and and a replaced CPS (my stalling while driving issues) , you name it, I've been there...Thanks for your help Made_In_Japan. '94 850 n/a

Guest · Post by **Guest** » 01 Feb 2006, 06:41

Followup Question for MadeInJapan and others

OK, gonna try the slow recharged battery on Thursday afternoon looks like. That means the car will have sat from Saturday afternoon to Thursday afternoon = 5 days.

I'm wondering now if I should pump the gas pedal a few (2) times and then hold the pedal to the metal while cranking or just go pedal to metal w/o pumping first..

Or is the gas to the engine not a problem after sitting that long?

95autoturbo · Post by **95autoturbo** » 01 Feb 2006, 11:52

worst scenario is you would have to replace the wiring harness...........

Post by **MadeInJapan** » 01 Feb 2006, 18:32

Don't think it will hurt to pump it a couple of times, but if the fuel pump is working correctly, the key in position II will do the same thing for you. Just turn the key on and after about 10 seconds, try starting it. Good luck!

Guest · Post by **Guest** » 02 Feb 2006, 07:21

Once again, thanks for the input MadeInJapan (oh how ironic that is, the 2 Japanese cars running flawlessly while I deal yet again with the Volvo).

One last question then. Do you think it's worth using one of our other cars to jump the Volvo while trying to start it or should I try the Volvo unjumped. I 'm paranoid about somehow screwing up the other car, which is why I stopped that on Monday, but at the same time I want to make sure I have enough "juice" to give the Volvo a pretty long crank with pedal to metal. Because in the end it just may be the Volvo battery. I was thinking if I try it unjumped, I'll confirm that for sure. It will be about 55F today here at attempt. If I get her goimg though, my driving pattern is such that may be enough to keep her charged although, I guess, ~$60 bucks for a new battery will look good whether I ever get her going again or sell it saying it has a new battery, but buyer has to get her running..

BTW, the 60 seconds you mention in a post above seems like an awfull long time to try and crank a car over for. I tend to stop after about 5-10 seconds thinking based, I think, on I was told years ago that I may damage some other component, like the starter, etc..

Post by **MadeInJapan** » 02 Feb 2006, 19:46

http://www.brickboard.com/AWD/index.htm?id=576164
http://www.brickboard.com/AWD/index.htm?id=1028440

I hope these threads help. From reading these, you will find that by flooring the gas, the ECU thinks that the engine is flooded and won't send any more gas into the engine. This seems to help with the cranking.

My name, even though I'm American is because I was born and grew up in Japan. I have owned Japanese cars...Mitsubishi and Honda's but much prefer the 3 Volvo's we have owned.

I hope you figure out your 850's issues and you get your car started.