I've had this 1983 242 for about 9 months. Non turbo, auto trans. Has never had problem starting, ever. Horrible squeak coming from alt. belts lately (cold)...so decided to change the 3 bushings that were quite shot, and two brand new belts. Was so excited to go for test drive to enjoy the squeak free operation...but it wouldn't start. Cranks over OK, but not even a cough or burp.

I pulled the coil wire boot from center of the distributor to see if it had spark. Appears no spark at all. Very odd, as it started/ran fine before the alternator bushing/belt job. I did have the alternator out of the mount, but was careful to not put strain on any of the wiring there. I'm afraid I must have yanked too hard on something accidentally...but for the life of me can't figure out what. There is a large blue wire at bottom of back of alternator, which I'm assuming is a ground. Then the large red wire that goes to center post, with plastic insulator cap on it. Then a small red wire that I assumed went to a corresponding blade terminal on back of alternator just above the main terminal. It fit there perfectly (terminal size, and wire length) even though I didn't purposely unplug it, it must have come off when I took the adjuster bracket off and the alt. pivoted towards the firewall. So, I hooked that red wire there. Oh, should point out this has had a new wiring harness installed by PO. I didn't get that deep into anything, that would lead me to believe I disconnected something...but obviously I did something. All fuses good. Not sure the best place/way to start troubleshooting this, and thought you good people may be able to assist. Any ideas would be appreciated.

Thanks in advance, and Merry Christmas!

 

Troubleshooting Guide To Volvo 240 No-starts And Stalls - Volvo Forum : Volvo Forums

 

Thanks for the link. In the page you directed me to, there is another link under spark section, for 83-88 diagnostic flow chart. No matter what i try, I cannot that link to work. I get a "sorry an error occurred" message page. I've also tried to search out that post through other searches, but can't seem to find. Anybody have a better link.

Also, I know it's possible that the loss of spark coincidentally happened at the same time I changed the bushings/belt at the alternator...but I don't think it is. If anybody has any specific ideas on what I could have done while in that area of the engine bay (my work was very central to that area) , I'd appreciate any thoughts on that subject.

Thanks again!

 

did you register for the forum and log on? I think that's required to follow that link, although I could be wrong.

 

Hey Pierce, you've helped me with some issue in the past. I'm loggin in here, but I guess "volvoforums" and "volvo-forums" are two different sights? So I thought I was logged in, but perhaps I need to register there also. So I tried doing that, but the "anti spam" question is "what year was it last year". So, thinking I'm pretty smart, I typed "2013" as my answer. But it keeps coming back to registration page with that answer marked as "data in this field is an invalid format". Guess I'm not as smart as I thought I was. What would be a better answer to that question?

EDIT: OK, apparently last year was actually 2011 in volvo-forum land. Or at least it didn't kick me back with that entry having a "red X" now. I've still to receive an email link to complete registration, but fingers crossed.

Since my first post, I've figured out a couple of things. I do have a Hall effect sensor type distributor, but not one with the little black plastic box connector everybody shows in their posting. Mine has a 6" length of wrapped wires coming out of the distributor with a 3 prong round rubber connector. The corresponding connector goes to the ICU, with 3 wires: yellow, green, black. I've checked continuity from the dizzy side connector and the plug that goes into the ICU. No broken wires, good continuity. I also read that a "quick test" for the Hall, is to turn over the engine and watch the tach. If it does little jumps as it cranks, apparently the hall supposed to be doing it's job. Mine jumps like it should. There are also other more involved tests checking voltage/ohms at the wires that go to the Hall. But my dizzy doesn't look like the ones shown (black box connector again) so I don't know wire colors or how they correspond to the ICU side of the connector. Looking forward to figuring out where to go from here (hopefully not the shop! I have faith in all of you).

 

just did an edit to last, with update info...prolly should have used reply instead. sorry.

 

Hi Pierce,
Still no word or confirmation email from "volvo-forums" so I can view that flow chart. But seeing as they are still using 2011 as the answer to "what year was it last year" I'm assuming they haven't been getting many new members for some time, and I question their relevance in the volvo community going forward.

So, perhaps you can assist me a bit (I'm hoping). I found another post of yours from back in 2012, where a another member had a no spark condition on a 1986 that also has the "simpler" system like mine. I've pasted a link to it below. You did a good job of explaining the "flow" of the ignition system! Although I am a little confused by it. Trying to avoid the shotgun parts-canon approach if I can, and I don't have another working 240 laying around to do some known-good parts swaping for the process of elimination.

https://volvoforums.com/forum/volvo-...-module-66283/

I've narrowed it down (assuming it's not just a bad wire someplace...but it has new wiriing harnesses) to the hall sensor, coil, or ICU. This was very much a "worked one moment and not the next". No sputtering, getting stranded on the road, on again/off again processed involved, like seems to be common with these types of issues. Always started great, changed alternator bushings/belt...absolutely no spark since immediately finishing job. So what would be ever so helpful, would be a way to see where the break in the ignition chain is.

I know I have power at the blue wire at ICU when key is on. I have power at the coil with key on. How do I know if the ICU is sending a signal to the coil to create a spark for the distributor (I have test light, volt/ohm meter)? I'm assuming, from your previous post linked above, would have something to do with the ICU green wire #1. Easiest way possible is good for my limited electrical experience. I did find the Hall test procedure (one simple, one involved). Mine passes the simple test, in that the tach jumps at every crank. Haven't done the involved test, as I have the round plug style at distributor, and suppose I have to strip away the black sheathing to determine which wire is which color at the connector (?), in order to do that. Or is going further with the Hall warranted? Not sure how the hall comes in to play, in regard to the ICU sending spark signal to coil, but obviously it's all connected.

Again, I really appreciate your time and help. I've got a tremendous amount of good info from many of your posts since I've got the car 9 months ago...thats helped me get this car sorted so far. Your a veritable vat of volvo knowledge!

 

PROBLEM SOLVED:

Very much a "duh moment" over here. I appreciate all the help so far. Turned out that when the alternator pivoted down when releasing the bracket for bushing replacement, it unplugged the connector from the ICU (one spade / 2 white wires) that I think is probably the connector from main wire harness to the ignition wiring harness (not exactly sure, but makes sense). Since the other side of that connection, by the alternator, fell down and under the block I didn't see it while inspecting for unplugged wires, damage, etc. When I decided to go deeper on wiring inspection while awaiting more help on component diagnosis from you fine people, I saw that "dangler" and noted it reached perfectly to that that little plug from the ICU. I would have figured it out sooner, but I thought that plug from the ICU was probably for an option or bypassed component/system (a/c, turbo, cruise, etc). Since it has some mods by previous owners (wiring harnesses, by pass a/c pulley, bypass OD, etc, etc) seeing connectors with no partner is pretty normal on this car (should probably give all those the shrinkwrap treatment to avoid these things going forward). I know you would have helped me get to this point, but glad it didn't cost any money!
Thanks!
Doug

 

the "Chrysler" ICU itself has a 10 pin connector, which is quite fragile and shouldn't be messed with unless absolutely necessary.

oh, I see, right near the ICU on the 84 schematic (I don't have a 83 schematic) is a 2 pin connector, one wire is white-red, and the other is blue on one side and has a blue and a brown wire on the other side? thats blue wire is power to the ICU, and the brown wire is power to the coil pin 15. not sure what the white-red wire is, its not part of the ignition circuit from what I can see....

 

Yeah...there are three "branches" coming off the ICU plug. The main batch goes down by the alternator, up around the timing belt cover includes the 3 wires to the distributor and a couple others. Another branch goes through the firewall and up by the wiper motor and plugs into a connector that is the blue/brown/white-red that you mentioned (yes relating to power to ICU and brown to coil). The 3rd branch at the ICU (the one that accidentally unplugged) has two "whitish" (if stripes on them..very faint) wires but a single spade connector that plugs to another sheathed wire (not sure of color without going out to garage) that also runs down and behind the alternator. I'm not exactly sure where it goes either. I found a couple wire diagrams, as well as some photos of actually wire looms from Dave Barton...I haven't figured out exactly where those go, as I didn't spend time down there yet tracking them. However, I know one thing; when plugged in you have spark at coil and plugs. When unplugged, you have neither. I think part of the frustration with with electrical issues on these 30+ year old cars...is that there are subtle changes with the way things are wired from year to year, European vs. USA, turbo vs. non, etc., etc. So you find some info that you think relates to your situation, only to find it doesn't (ie: hall / cps, power stage / ICU, etc). Thank the good Lord for these forums!!

Doug

 

my reference source for the wiring of these cars is the CD set sold by VCOA (Volvo Owners Club), one disk for 240/260, another for 940/960, and a 3rd one I don't have for 740/760. These have a wide selection of the 'greenbook' service manuals on them, including year by year wiring diagrams, showing all the variations. They are very copy protected.