I am trying to fix my mother-in-laws 96 850 wagon (NA). The battery was dying in it and it was working fine one day, then wouldn't start. If it was just short on spark it sounds like the cam or crank sensor, but the dash lights not working is the weird part, I am talking about all the idiot lights that should come on when you turn the key to the ON position.

I do quite a bit of work on cars, but this one has me stumped. The only thing that made sense was a bad ECU, but that was replaced and did not help. Interior lights and windows work fine, as well as headlights. Any time the car is switched to the ON position the pump at the right front of the engine runs constantly, seems like some sort of air pump.

Thanks in advance for the help!

 

Did you replace the battery? Also, did you clean the battery cable connections real good?

 

If you did played witht the battery cables then you might have missed connecting all the cables. There is a extra red wire that runs to the battery terminal and feeds the controlling electronics. Just some food for thought.

 

thanks that was tasty... any update????

 

The car cranks over just fine and the battery is new, so power is not the issue. Is there a fusible link or anything on the car? It just feels something like that is wrong. I have checked all the fuses in the fuse box, and they are all fine.

The red wire spoken of above is connected, as are all the other wires. The headlights and everything work fine on the car.

 

Maybe it is two things. The crank/cam sensor and that is the no spark. The lights on the dash something else. You can test those sensors if i am not mistaken.

 

The cam and crank sensor were both replaced not too long ago, but I am not ruling anything out as there may have been a power spike or something from the battery going bad. I would look there first except for the dash light issue, they have to be correlated as they happened at the same time.

Has anyone ever had the ignition computer go out before? The car acts the same with the ignition computer in or out, I wouldn't think it would control dash lights though.

 

Check and make sure the connector for the small wires on the positive terminal did not break off.

 

Nope, all of the wires are good. Is there a fuse anywhere inline with that wire?

 

Not that I know of.

Also check the power wire at the starter and alternator and make sure those connections are tight.

 

The car turns over just fine, there are interior lights and head lights, just no spark and no idiot lights on the dash.

 

You are missing power from somewhere. Once you track it down it will run.
I will try to dig up a diagram.

 

Try checking the ignition switch, under the lower column cover behind the tumbler...

 

I have done some more checking. I don't have any spark and I am not sure about fuel. I found an overload relay that was blown (+15v). I tried a generic one that fit in the socket (odd 5 prong shape), but either it didn't work or that one blew also. I am going to head to the junk yard tomorrow and grab a few more. I am also going to grab a main relay. It operated the same with or without the main relay hooked up. I am convinced it was a power spike or something like that. Anyone know what would happen if the polarity was reversed? I would think it would blow the overload relay. Would it do anything else?

 

Not sure what exactly would happen never had one that had it happen to.

 

It runs! Thanks for the help everyone! Thanks to the diagram I got from a member on here I was able to find those overload relays. I hit up the junk yard yesterday and got some new ones, popped one in for the blown one and got dash lights, then it fired right up! Thanks again for the help!

FYI, the relays are in with the fuse box. You have to take the cover off the fuse box (4 torx screws) then you can see them. There are 3 of them with a big J on them. The one that was blown for me was the middle one.

 

Thanks for the update.