Pulled off the small wire and got nothing at the spade on the alt. Later after it cools off I'll cut back the sheath thing.



Dat stance.

EDIT: Oh yeah, my overdrive relay bypass works great. Very happy with it.

 

So I cut the sheath thing back as far as I could and I still couldn't get enough to stop the wires from touching. Since the oil pressure thing seems to be destroyed anyway, I opened up the sheath further down and snipped the black wire. Literally nothing changed. What do I test next?

 

Best bet to avoiding problems going forward is to replace the engine wiring harness. You've found a couple of wires that are bad which means chances are there are more in the wiring harness that have no insulation which will cause all kinds of bad running conditions.

To get the alternator to charge, you could try running a separate small red wire up to the batt light in the instrument cluster. However, you need to get a wiring diagram to find out which pins it goes to on the cluster connector.

 

What does the battery light/little wire do anyway? The light does come on and stay on dimly so I assume there's a connection to something.

 

I just don't get it. It used to get a battery light with either cluster, but now it's just very dim. Even the other lights are dim until they have to come on normally, like the parking brake light. The little red wire is getting under 8v, nothing with the engine off and key in position 2, and nothing alternator side with it disconnected and running. So I spent $40 on a used 740 alternator from a parts site, should be ready for pickup sometime.

Also my radio is terrible. I can't get the actual radio to do anything anymore, and when using a cassette to audio jack adapter it sounds pretty bad. The little cover that shows what station the needle is on fell off too. Also my drivers side speaker stopped working while the passenger side wasn't working until I fixed it.. I guess I'll just get super cheap replacement speakers and an ugly Chinese head unit.

 

The small red wire runs from the alternator through the battery light, through fuse 13 which is connected to the battery through the ignition switch. This is the exciter wire on the alternator and without proper connection, the alternator will not start charging.

Your car has wiring harness issues and you will continue to have problems like this unless you face up and trace down the wiring problems. The insulation on the wires degrades with time and heat and flakes off causing various wires to short together. It was a known issue for models from '84 through '86. Google Volvo 240 biodegradable wiring and you will find pictures and descriptions of this problem.

 

Hm. I tried using a wire to connect the small tab directly to the positive terminal, voltage stayed the same and nothing happened. So I'll just wait until I get my new alternator and see how that works.

 

Welp, it happened. Got stranded with a dead battery. Got it home by letting it charge off another car for awhile. Still nothing from the used parts supplier about my alternator. Gonna check the wiring more later.

 

Did a bit more testing and making sure the wire isn't shorting on anything, getting the full 12v at the little red wire when disconnected from the alt and 8v when connected, nothing on the spade connector alternator side with the wire disconnected, running or not. This makes me think that it really is an alternator and not a wiring problem. Now if only the parts place will call and say my alt is ready..

 

STILL waiting on that alternator. Gonna give that auto place a call sometime. In the meantime, I've got some AC stuff in the mail. Cheapo pneumatic vacuum pump to try and evacuate the system, R134a with ester charge, and a line for the can.

Earlier today I got an old $30 air compressor. I think 2hp, two cylinder, etc. One cylinder needs new valves or something and just blows straight out the filter, but the other one builds up pressure fine. Also ordered compressor tools and a hose.

 

Did my tacho today. The wiring back there was a bit of a mess, looked like someone installed something and then removed it as sloppily as they could. Cleaned it up pretty well and wired in the tach. Positive off the ignition, positive off the wire for the lights in the cluster, (So the tach light is controlled by the dimmer) the signal wire, and ground. Works pretty well except for at high RPMs. I took it up to the rev limiter for a second and it was bouncing like mad. But I'm happy with it.

 

Talked to the parts place, apparently they just didn't call for some reason and my alternator was ready. Got over there and picked it up. It's a '92 740 alt, not sure if 70 or 80a. Old one is 70a. Got it on with minor hiccups and it works perfectly. Now I can drive for more than 5 miles without fear of being stranded.

alternation nayshun - Album on Imgur

 

Whoo, fixed my AC. Ended up drilling out the stock R12 port so the adapter would work right. Except after the first can with ester charge the valve got stuck and immediately let all the pressure out. Messed around with it, pulled a vacuum again, and put in a can of generic R134A. It ****in works. All the electricals, everything. I did leave the hose on the fill port because I'm afraid that the valve will get stuck again if I take it off.

I went to the auto parts store to buy a second can to replace the wasted one and at a light some idiot in a pickup was trying to turn right while I was turning left. So he starts to go past me in the single lane. Not enough room, so what does he do? Hit my car. It was very minor, but I definitely felt it and got angry. Oh well, at least I have AC.

 

Today I ripped out my door dinger. Hate that chime sound. Also my drivers front tire is leaking faster now. I filled it like yesterday and today it was at 20PSI. AC is still working good so I'm not gonna touch that again until it stops working, which it probably will eventually. Did my spark plugs yesterday. Old ones looked mostly okay to me. Today I found some dirt and man, RWD is fun.

 

So all my dash lights were flickering on and off when I revved the engine/went over bumps and stuff. Looked under the hood and saw that the little wire on the alternator came off and was shorting. Crimped it down a bit and put it back on, seems fine now. Last night I made an IPD order for a buncha stuff. Bulbs for the dash and center console, some interior clips, a battery tray, pedal pads, endlink bushing kit, both tailgate wiring harnesses, etc. Also ordered a diff gasket because it looks like there's a leak from one of the bottom bolts on the cover.

Also my hood light started working.

 

Did my $16 aftermarket radio today. Sounds pretty good compared to the old Kraco with a cassette adapter. Only real issue is that I didn't wanna take the gauge cluster out to find a constant 12v wire so the radio loses all its memory every time I turn the car off for now. Looks worse than the Kraco, like it doesn't belong, but I'm willing to live with that. If anyone wants the old KID-B588D with the cover and everything, just message me.



radio 6/13 - Album on Imgur

 

check all your heavy alternator wiring. good chance the alternator isn't grounded or you have some bad connections creating havoc.

I think it's normal for both the high and low beam to come on when you pull back on the high low beam switch, it's to flash people who won't let you by when you are screaming down the autobhan ;-) yea you won't need that feature much ;-) in north america people reach for their handgiuns or stomp on their brakes if you pull that trick. here it's considerd rude, but in europe maybe it's normal. if you did that behind me I'd doubleclutch and drop a gear so you didn't see my tail lights and squirt you with my rear wiper and then speed off with my brake lights on while you fought with your wipers ;-)

I'd run it a week and change the oil again. good to flush out whatever was in it before you got it. just to get some of the crud out and since you;ll have to drain it to fix the plug and you'll likely get grit in the oil by the time you drain and refill it. I'd run 20W 50 since it's probably pretty well worn. the filter will be ok.

the overdrive wiring does go through the switch on the shifter but it also goes through a 4th gear switch on the transmission. If you want you can jump this connector to test if that's the issue , then you;ll get overdrive in every gear. don't drive it like that though. it wouldnt be so bad if it only worked in 3rd and 4th but if you are stepping on the gas in first or reverse and you accidentally put it in or out of overdrive you might break the transmission. I have a casing for a 122 tranny where they broke the transmission housing right in half by doing just this. not sure how the overdrive would fare if you enguaged it when in reverse Lets not try that.. you can check the switch in place with a meter if you prefer. it should be closed when in 4th getar and open in any other gear.

that 4th switch might be bad, I have seen them go south. if you want you can run a wire from the coil on the overdrive with a light to see when it is on and when it isn't or use your meter to check. You proabably have a light in the dash that does this.

the problem could also be the coil on the overdrive. I think it's designed with two coils. one is to pull the solenoid in and it's hot when you shift it , and the other is a holding circuit and that keeps the overdrive solenoid engaged. it'll drop out of overdrive and shouldn't go back in on it's own if you shift to neutral and back to 4th gear because doing so will open the holding circuit. not sure where the relay is located but there probably is one and you might be able to hear it clicking if you switch it when the car is not running. youll find the fuel pump relay and the one for intermittent wipers around under your drivers feet near the carpets. It might be around there.. but could be int he engine bay..
your overdrive should only switch in and out when it's in the 4th gear. there will be another similar switch on the tranny for reverse gear - backup lights. you should be able to put it in 4th and hear it click in and out when the car is not running. Im forget if the wires run through the switch or if there is just one wire that gets grounded when the switch is closed. might beeither way bit it's not complicated you just have to get under the car to find it.

I think some volvos had a button to enguage the overdrive and some may have a switch so there could be subtle differences. on my 122 it has a paddle switch similar to the signal flipper but on the other side of the column. it's a 123 part.

 

I haven't seen any evidence of oil leaking from the drain plug so I'm leaving it until it's time for the next oil change. Running 15w40 BTW. Already fixed the alternator and all its issues by replacing it. I did try a new regulator/brushes on the old one with no effect but the new one solved all issues. As for the overdrive, the wires to the button in the shifter didn't seem to have a connection at all on the relay so I just did a bypass with an AC switch out of a newer 240 and it's been working great so far. I've made sure not to use it outside of 4th and it hasn't had a single issue so far.

 

Took it to a tire shop and they found a screw. A patch later and now I have a nice non-leaky tire. Ordered some AC stuff. It's still blowing fairly cold, but I want to hook up a manifold and pull a full vacuum then fill with the proper amount and some oil. Ordered a new drier with a R134 fill port to make things easier and a buncha cheap R134.

 

Wet sanded my headlights up to 600 grit and couldn't find anything above 1000 at the hardware or auto store so I left it at that and put some UV resistant clearcoat on. Waxed the whole car and my fresh shiny headlights then gave it a good wash with the power washer. It shines now.

Before:


After:


6/15 - Album on Imgur