Hi there
1981 240 B21F
Tracing the short in the fuel or ignition system, I just thought i would check to see if i am making any really obvious wiring errors.
Off the coil, the brown wire is on the side labeled +, the red-white wire is on the side labeled -. Correct?
Off the starter solenoid the blue-yellow pair are on the drivers side of the car (towards the wheel), the brown on the passenger side of the car. (i cant see any markings on the solenoid from here) Also correct?
Still greasy and grumpy...
Delphine

Yet another mystery wire: The r-w wire from the coil goes to the ignition control box, hooks into a white wire out of it, which then splits into 2 r-w wires that go through the firewall, one goes to the fuel relay, the other to a female end that is bundled with the instrument panel wires but doesnt seem to hook to anything there (theres a nonused male connector off the back of the panel, but it is a small one, not normal sized, dont know what goes there either)
This car just gets weirder the deeper i dig. I'm taking notes on all this and drawing a "what is in this car" wiring diagram that i'll show off once it makes sense...
Delphine

Delphine,
Checking your description to the wiring manual. It seems everything is correct. Except for the one wire?
When you get a drawing of the wiring. Please post.
I like a challenge.
Wayne

Wayne: the file for the drawing is 17 mgs of bitmap. it's extensive. i dont think i can post it. i can mail it to you zipped if you want... but i'm still revising it as i dig through the car... i can mail you just the section i am sure of (the stuff around the fuel relay) if you want...
The brown wire does change to blue off the control module, i see no ballast resistor.
I removed an aftermarket cruise control when i started messing with the wiring, it didnt work and was in my way. i'm wondering if something from that surgery is still hooked in somewhere. i thought i got it all...
Last thing it did last night, after i had rechecked all the wires, resoldered the relay and tried to start it was blow the #5 (i think) fuse again. At least it didnt blow the relay, i think i did a better solder job, so it blew the fuse instead...
Thank you for your continuing interest in this, if nothing else it helps to talk to someone who knows what i'm talking about. My friends and family are just flat lost when i say anything about this car after "it still doesnt run" :)
Delphine

Hi Again,
Hang in there! I know it's fustrating.
O.K.- going back to the brown wire to the ignition module.
From fuse # 11 there is a blue wire that tee's off. One side goes to the ignition module terminal # 15. The other side goes straight to the ballast resistor. Then from the resistor ( color changes) to brown to the ignition coil terminal # 15+.
As far as #7 fuse goes. That is the main fuel pump.
Here is a suggestion. Can you remove the wire connectors from the main pump. Turn on power & see if the fuse blows again?
Also do you have a multi meter?
Wayne

Sorry about spelling errors in last message. I reread it a bit too late.
Forgot to say about removing the wires to the main pump: that involves jacking the car up, and doing surgery on the underside. I'm not feeling well today so i'm not pushing myself to do things like jacking etc. I did pull the fuel pump wires off the relay and got another blown fuse for my efforts.. wonder if i should pull wires off the relay one at a time and see what does and doesnt blow fuses...?

Here goes.
First the ballast resistor looks like a short white cigarette. It's by the passenger side along the left wheewell. Just below the hood hinge assy. Two wires connect to it.
You mentioned that you did disconnect the wires to the pump at the relay for the fuel pump. And got another blown fuse!
O.K. this eliminates the fuel pump as being the problem. One step at a time. What I'm trying to do is work backwards till you no longer get a blown fuse. You are right in eliminating one wire at a time.
The only concern here is how many fuses till the problem is found.
With the pump wires still disconnected try removing another wire till only the power wire is left- #30. What happened???
Wayne

Hi :)
Ok, there is no such item that fits the description of the ballast resistor anywhere in the engine bay.
Fuses are cheap :)
Removing the blue pair of wires (87b) makes the car run, nothing blows, starts right up. i'd say they are the issue. One of them goes to the control pressure regulator, one goes to a junction where it hits the brown wire from the coil, and then continues blue to the ECU.(going nowhere near any ballast resistor along the way).
Will try to upload the cropped bit of the wiring diagram thats relevant to my webspace www.zianet.com/~dtomei, check and see if it's there. and if it is, forgive the ragged bits, i blew it up to 36 x 36 inches and had it printed on a blueprint machine and mounted it on a board to use while i fought with the wiring, it artifacted bad when enlarged, and not all of it has been repaired. I think everything in that segment is accurate according to the car.
Delphine

Webfile address correction:

www.zianet.com/dtomei/WiringCrop.tif

my brain likes to think of too many things at once, computers and cars at the same time overloads me :)

I am informed that that file is huge, (issues with my computer about saving files to some formats) so it has been made smaller. the smaller version is:
www.zianet.com/dtomei/WiringCrop.gif
:) Delphine

Hello,
First Is your engine a B21f- MPG? If so then you are right! There is no ballast resistor in the system. Sorry for chasing a ghost. I have a B21F.
Any way, glad to see that the car is running. O.K., now I check the web site of the wiring diagram. WOW! It's huge.
I'll be printing a section at a time. Then tape it all together.
Let me study it for awhile & get back to you.
Wayne

One more item.
Checking the wiring diagram between the ignition & fuel systems for the blue wires. One goes to the ignition coil after changing to brown. If the car runs then at this point I will assume that one side of the blue wire is O.K. The diagram only shows one wire(brown) at the coil. Do you see more then one wire on the + side of the coil? I know sometimes diagram can be misleading. This would leave the other blue wire going to the control pressure regulator.
Can you disconnect the connector on top of the regulator and see what happens. This is with the connector on #87b installed on the fuel pump relay.
The reason for this is- 1) the heating element inside the regulator is shorted or more of a possibilty 2) the 'infamous' wire bundle under the intake manifold that cracks insulation off wires due to heat. This could be the smoking gun?
I'm still working on the drawings by the way.
Wayne

Wayne! THE CAR RUNS!!!
I found the short!!!
Of all the stupid ways to short a wire, this has to be one of them: it had gotten caught between the intake manifold and the head and bolted tightly, making a lovely ground. Under the #3 leg of the manifold, where i couldnt see it.... had to tear the intake off to fix it.
Thank you SOOO much for all your help, and i'm still going to finish updating my wiring diagram before this game is over...You said that pic was big, it's about an 10th of the whole thing. it prints out to 36 x 36 inches... and i drew it pixel by pixel (literally)... Did the first version of the diagram in my manual before i tackled rewiring most of the car (lots of burned stuff) and as i have learned things they have been marked, so i can update. I should end up with a diagram thats big enough to read easily that is correct for that car (with all its quirks)
It RUNS!!!! :D :D :D
Delphine

Delphine,
I replied on the other post on a great job! By the way, I'm curious about
the wire under the manifold? Was it the wire to the control pressure reg?
It's great to hear about a success story.

Wayne: Thank you :)
yeah, control pressure regulator wire was trapped under the #3 leg of the intake manifold. I had traced it from both ends but couldnt reach it in the middle, only about 3 inches not accounted for, has to be ok, right? Wrong. squished flat under well torqued down nuts. i couldnt even get it off to just splice it without taking the manifold off. Blech, what a job. Today i'll put my interior back together and take it out for a run, blow out the crud....
Delphine

Hi :)
I have been amusing myself by removing the seat belt buzzer system! (it didnt work, and i dont need a reminder, and its just more wires in my way, plus its fun, as opposed to the stuff thats making me crazy)
Does a ballast resistor look a lot like just a double wire connector? that i have. thats all.have one of those by the in tank pump too, and the diagram clams theres a capacior there, but thats all i see.
I have a multi meter but am not very good at using it, i dont understand it. The directions for it assume you know what you are looking for, and i am never certain. i was taught to use it to check for shorts, have done that to all these wires that are in question.
Delphine

i was wrong: fuse #7 blew.

Hello Delphine,
I'm tracing the color wires in the Volvo 'green' manual. So far you are correct. The brown wire you describe on the passenger side? Off the starter soleniod? I don't see any brown wires?
By chance did you replace the fuel pump relay?
Wayne

Wayne:
Did i replace the fuel pump relay? Which time? a few months ago,then yesterday the bad relay was soldered by a mechanic and blew again immediately.(i posted it on the last thread). I must have a short somewhere, It's noplace obvious, thats why i thought i would make sure i wasnt doing something dumb with wires and not knowing it. My wiring diagram and my car both show a brown wire that comes from the coil to the starter and up to the fuse (#11). That one is hooked on the passenger side of the car side of the solenoid. i dunno if it matters, maybe all contacts off the solenoid are the same. I'm hunting for straws here, anything that might be wrong. I have no obvious shorts, but something is bad.

Hello again Delphine,
I went back to the first post you mentioned & saw you did replace the relay. Sorry I didn't see it earlier. Anyway, the brown wire you mentioned is correct. I was looking at the diahgram for CI fuel injection system. I looked up the starting circuit and found the 'brown' wire you spoke of.
Yes, the wire connects to #16 terminal on the starter goes to the ballast resistor and then to terminal #15 of the ignition coil.
From what I see. Power comes directly from the battery to terminal #30 on the starter. No fuse #11? Can you give me more details from where to where this wire connects to?
Fuse #11 is for the overdrive & rear demist.

Still checking.
The wire to fuse #11 should be a 'blue' wire from fuse to the ballast resistor. This then tees off to the ignition control module.