.Hi all - I keep blowing the #11 fuse, which services overdrive and rear defogger. The fuse seems to pop primarily when turning the car off. Overdrive otherwise works fine when the fuse is intact.

I have disconnected the larger blue wire from the #11 fuse, which goes to the rear defogger, so i know that is not the issue.

I have also eliminated the relay by wiring around it, and have corrected a previous short in the white wire running from the solenoid.

Don't know why the fuse keeps blowing. If there were other shorts, wouldn't the fuse blow at other times besides when turning the key to off?

Any ideas?

thanks,
John

I am not sure what you re wired but often the problem is the solenoid wire shorting against the transmission or where it goes into the interior of the car.

Dan

I checked the wire from the solenoid again and there was a tiny nick in the insulation where it entered the shifter box, which I have repaired. Seems to be holding at the moment.

Still can't understand why the fuse would blow when turning off the car, but maybe it won't happen again.

thanks all-
John

You may want to recheck anything you changed since you first encountered problems with your overdrive circuit from this prior threads.

https://www.brickboard.com/RWD/index.htm?id=1632121&show_all=1

Without a Bentley to show me ...



https://www.amazon.com/Volvo-240-Service-Manual-1983/dp/0837616263

... and that all my 240s all had or have manual transmission, so I'm guessin'.

Also, while anemic, you have:

http://www.volvowiringdiagrams.com/?dir=

Specifically:
http://www.volvowiringdiagrams.com/?dir=volvo/240%20Wiring%20Diagrams

PDF Page 16 (over drive circuit), 23 (fuse box).

The diagram shows the circuit is powered at both sides when the the key is at on (dash lights) which = engine run after your start the engine.

I forget whether the automatic OD switch, as you press it, with the key set to on (dash lights, yet engine OFF), changes the OD light on the dash?

Does the #11 fuse blow when you turn the dash lights on, and then off?

Also, courtesy of Dave Barton, we have:
http://www.davebarton.com/volvorelays.html

Specifically:
http://www.davebarton.com/volvorelays.html#overdriverelays

Specifically, location description:
http://www.davebarton.com/pdf/relay_93_240.pdf
See item 108.

Dave Barton's image of the OEM Volvo overdrive relay. Made in Germany by Kaehler.


Tasca Parts for 83$


http://www.tascaparts.com/oe-volvo/3523804

While driving, does the OD dash lamp illuminate when you press the on-shift-level OD switch, and the transmission drops from OD to the lower gear? You've tried this?

You may need to open the dash from dash head removal to the center console. Perhaps what you believed to be the overdrive circuit relay with what you replaced it with may be suspect?

In the wiring diagram, both wires on the fuse #11 position load side are shown to have blue with black striped insulation. That may vary.

So, you may trouble shoot with your trusty multimeter for voltages of a spurious nature or continuity faults, such as shorts and discontinuous (broken) circuits.

Others may consider other fault causes as you post back what you're testing.

Questions?

(For others. I'm no auto transmission guy. All three pedals here, as Uncle oldduke says.)

cheers,

dud.
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