1979 242 coupe charging issues.

Symptoms:

install new battery
replace alternator

after 2 days(driving at rest) the battery gets the life sucked out of it...first the lights start to get dim and my turn signals go out, then I start to stall everywhere and I need to press the accelerator more. At night as I am driving, and the dash is dying, I turn off the lights and my car accelerates/idles normal....

I recharge the battery and everything runs smooth!!! for two days anyways.

I bought it without the original light switch and the old timer mickey- moused the light switch and installed a toggle switch to turn on/off the lights.
Belt is not loose or insanely tight.

some fuse missing

 

have you tested the charging voltage with a volt meter ? a full charged battery that's rested a couple hours should be about 12.6V (give or take, depending on temperature and charge state). when the car is running, it should be at LEAST 1 volt higher from the alternator. if its not, the alternator isn't working right.

I'd not be even a little surprised that your new alternator isnt working right, especially if its a bigboxstore special.

or maybe the D+ circuit isn't working. when you turn the key on, does the alternator light come on the dashboard? and when you start the car, does it go out? the alternator light is an important part of the charging circuit, it provides the 'bootstrap' power so the alternator can fire up.

 

The alternator is bad.....! I got me a volt meter now and it did not read a volt higher rather a volt less...and less and less as it ran....alternator completely non existent...

a no name NEW alternator for sure....


will get a junk yard one instead....


Thanks for your reply!!!!

 

does the alternator light come on when you switch on the car before you start it? it should. if it doesn't, the alternator won't work. if the bulb is burned out, the alternator won't work. if the right wire isn't connected to D+ on the back of the alternator, the alternator won't work. battery + goes to the ignition key switch, then to the indicator light, then from the light to the D+ terminal on the regulator. current must flow through this bulb to generate an 'excitation field' in the alternator. once the alternator is spinning and generating voltage, this light goes out because D+ is at the same voltage as the battery (the battery is connected to the B+ lug on the alternator, via the starter hot terminal).



Do you still have your original alternator? If it was an original Bosch/Volvo alternator, chances are pretty good it just needed cleaning up, and a new regulator/brush module, those are cheap enough.

oooh, a 1979? that might be one of the really old style alternators, hmmm.

here's some stuff on the regulator and etc.
VOLVO Parts and Accessoires. VOLVO Parts for VOLVO repair and VOLVO Performance upgrade! www.VLVworld.com sells New and Used VOLVO parts for 240, 850, 740, 760, 940, S70, V70, S40, V40, S80, 140, 122, 164 and More

 

I did not properly tension the belt so it was not charging at all....new belt and yes the alternator is a bit peculiar. I got 14Volts on the meter when running and battery charges good....

Now I developed a new problem with the alternator working....my in tank pump went out...

1) tightened the alt belt
2) replaced a relay next to battery...the one that is next to a small plastic junction box and a smaller relay...my original read 150w and had a new one that read 250w? Original is pretty nasty looking(still works?) but decided to replace. I see this in all 240s.

3) changed the small relay in the same line..with a new one that had the same numbers corresponding to each connection.

turned on the car and it started fine...test drove at 40mph max and struggling for fuel.
jumped fuel relay and activated main pump.
WHERE IS THE RELAY FOR THE IN TANK PUMP? DOES THE MAIN PUMP RELAY CONTROL BOTH? I replaced the intank pump with another one and tested for power to the in tank pump and no go.....I even replaced the "resistor" nothing...

thank you again for your reply

 

I actually replaced the "headlamp step relay" & "power window relay also multipurpose"

headlamp step relay on my original is 150w and replaced with 250w one...
the multipurpose one is a bit of a odd one...who knows what the hell it is for...

 

let me see if I have the diagrams for a 1979, thats older than I've ever worked on (our 240 is a 87). ok, its CIS of course (also called K-Jetronic or K-Jet for short).

wow, thats a different one... the relay on a 1979 is /only/ for the fuel pumps, also powers the 'control pressure governor' (I suspect htats the moduolator on the side of the CIS fuel distributor?), and the auxilliary air valve. fuse 7 provides power for the relay. the tank pump is on fuse 5, but the main one is directly off the relay. this relay looks to have 6 pins, and has some control logic in it (eg, its not just a simple relay). This relay looks to be on the drivers side of the firewall, probably above the clutch pedal mount bracket?

of course, with CIS there is no electronic fuel injection controller, the ECU is only on the LH systems.

 

thanks...I think the fuel relay is burnt(partially) because the fuse on 5 and 7 are ok but can't hear a thing coming from the pre pump and I used to two days ago. I got to order me a relay now. I found a few junk yard 70's & 1980 240s with CIS but of course EVERY SINGLE FUEL RELAY IS GONE...

Thanks for the info...freaking vital information....watch out for them earthquakes.

 

which engine is on this 1979 242DL ? I /think/ you need relay 3523639, which is $50ish at tascaparts (an actual Volvo dealer). 1979 is so old the parts catalog I have ("VADIS") is less reliable.

 

B21F non turbo...and that sounds about right $50 or more...pictures coming tonight....it has 740 wheels, owner just bought the 4 wheels because of them having new tires...looks ok.

Gratze!

 

nothing wrong with 740 wheels on a 240, they are a perfect fit... They are likely 15" which are easier to find tires for nowdays anyways, you'd put 205/60-15 on that instead of the original likely 195/70-14..

just out of mild curiousity, from this list, Volvo 200/700/900 Alloy Wheels which are they? I've got the Hydras on my 1992 740T wagon, but it came with the Aries. Draco or Virgo would both look right at home on a 240.

 

Dersus, Polished.

So go with the 205 (wider right?) and shorter than stock right? It does give it an odd look...

I remember a person around my middle school driving a red wagon with Hydras....740 turbo with tinted windows...I thought to myself..."that car was very different from the other wagons or minivans"...weird how now that I am into Volvo's I remember all the people that had them when I was a squirt.

 

ah, Derseus are 14", same as the original 240 wheels, so no, stick with the standard 240 size, P195/75-14 or whatever.

the 205 size I mentioned was specifically for 15 rims, which came on many 740's. its the same diameter as the p194/75-14 so the car rides at the same height.