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Alternator wire on 700 serie dash

Mr.Borrie

Mr.Borrie

The Sneaky F*ing Ukrainian
Joined
Aug 1, 2006
Location
Netherlands
My 780 diesel to petrol Lh2.4 conversion is running. However i still have 2 things to do

1. Get the alternator light wired up to the dashboard lamp (to get it charge)
2. Get the tach wiring sorted (i will need a 4 cyl dashboard i know)


Right now my main concern it to get nr1 fixed so i can actually drive it :-)

Now its been a few months and i do have a pink wire left that i marked alternator that one needs to go to the dashboard.

Now i just need to know what the pinout on a -89 dashboard is, the donor was a 940 and i used the diagram to cut down the loom to just LH, but i cannot seem to find a proper diagram that mentions color code of the pin-out of the 740/780 -89 dash.

Who has the right diagram for me or at least can tell me the pin-out or color of the wire i need?!

I found something similar for a 200 serie here: https://volvoforums.com/forum/volvo-240-740-940-12/gas-temp-gauges-not-working-my-240-dl-62169/
 
If it's different on a '90 740 I'm a jerk for giving you bad info, but it was red for me. C4 on the big 12-pin joint.

The diagram for the '90 I find much easier to read, but caveat emptor I guess since I don't know what changed in that year.
 
The 780 diesel was a 1986 if that helps.
Its a bit of an odball but i assume Same as the 740 diesel from 86

Another option would be to take the enginebay loom from the diesel (still there but cut short because of all the disintegrated insulation)

If i know the wire color of the wire in the enginebay i could make that work
 
Attached is a charging circuit diagram for '85 model year 7-series. Likely very similar or identical to '86. No distinction identified between the B230, B28 or D24 charging circuits listed in Greenbook. Hope this helps....
 

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sometimes you need to get some revs before the alternator is 'excited' enough for it to start charging and the dashlight light to go out.
other possibility: lightbulb popped? bad ground to the gauge cluster?
 
Janspeed said:
sometimes you need to get some revs before the alternator is 'excited' enough for it to start charging and the dashlight light to go out.
other possibility: lightbulb popped? bad ground to the gauge cluster?
Click to expand...

I get no light at all, i am suspecting the grounds too. The diagram hoever does not tell
Me where this ground is. I think wireloom driverside enginebay. Got all the black wires from the diesel loom to the chassis.

Rintje light burned out, small change but possible
 
The charge light doesn't use a ground in the dash. It uses the ground through the alternator case. then when the alternator is excited the ground disappears and the voltage is matched to make the light go out.
 
Try grounding the wire to the alternator case. If the light still doesn't come on. Check the alternaator case ground and make sure the bulb and the wiring from the dash to the alternator D+ is good. Of course make sure the bulb is good, too.
 
dl242gt said:
Try grounding the wire to the alternator case. If the light still doesn't come on. Check the alternaator case ground and make sure the bulb and the wiring from the dash to the alternator D+ is good. Of course make sure the bulb is good, too.
Click to expand...

Put the red wire from the dash on the altenator cover/ground directly ?
 
Yes, the small red goes to the bulb and when engine is off the alternator grounds the wire connection internally. So if you ground it to the case and turn on the key it should light the bulb. If it doesn't light then the bulb circuit has an issue or the case ground wire for the alternator may be open. You can move the small red wire to another gournd like the cylinder head and if it lights. Then the alternator case ground wire is bad.
 
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