Hi all,

My son's beloved '83 245 (290K and runs like a clock) has developed a 150ma parasitic drain on circuit # 6, which is main fuel pump, dome light, and brake lights.

On this older 240, with no key in the ignition, you can step on the brake and the brake lights will light. Could a worn brake light switch cause the drain?

I've pulled the fuel pump relay, and switched off the dome light, but I still measure the drain.

Maybe disconnect the brake light switch and see what happens?

Thx,

Monty
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Past: '79 245, '91 240, '88 245. Current: '90 245, '83 245, '95 940

I have a question too.

Is this a CIS injection system?


Phil

Yes it is, and in reviewing the Bentley manual, I discover that the main fuel pump is on #7, not on #6.
--
Past: '79 245, '91 240, '88 245. Current: '90 245, '83 245, '95 940

Does the car have a cruise control unit? It might be on or wired to be on all the time.
It is hook into the brake switch and might be wired on the wrong side or something crazy like that!

Phil

Hi all,

So, problem solved, and Phil wins the prize!

On circuit #6, which is brake lights only, a green/red wire runs from the fuse to the brake light switch. It's tied together at the switch with another green/red wire. This wire is for cruise control (which this car does not have). When I disconnected the cruise control wire, the drain disappeared. Since the car doesn't have cruise, I just taped the end of the wire, tied it out of the way, and will leave it at that.

Love these cars, love working on them.

Thanks for all the suggestions.

Monty
--
Past: '79 245, '91 240, '88 245. Current: '90 245, '83 245, '95 940

Thanks for the post back as I wondered what you found.

What a surprise to find out there was a prize. I do not know what the prize would be but any case it would a surprising, surprise, to get prizes! (:)

Glad I could help! It was the only thing that did not have a switch in the circuit. I was stumped when you said you did not have a cruise control. So, there was a wire but no fuse holder... Weird but then considering the years, no surprise! (:)

Whatever is on the other end of the wire sure was a small parasite. Maybe it is an alarm system you do not know you have either.
Now, that might later be your prize, when you go looking for something else within the arena of that dash jungle!

Thanks again for the follow up and an answer is the prize we all share.
Phil

Nope, no cruise control.
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Past: '79 245, '91 240, '88 245. Current: '90 245, '83 245, '95 940

So the drain goes away when you pull fuse number SIX right?

I ask, because I read a post about the discovery of SEVEN feeding the pumps.

I see that the brakes, courtesy light with the delay relay of which has a wire, green/red from it, going to the brake switch and onto the cruise control box (red) through a 4 ampere in-line fuse.

Is there one of those similair holders being used for anything else under there?

Does the dome light work properly in all three positions with the front click working on the delay relay? On always, centered and backwards for being totally turned off (smooch mode) which it is in now.

Phil

Phil,

Correct, the drain goes away if I pull #6. I can measure a 120ma draw across it.

The dome light appears to work correctly, but my son keeps it in the center (i.e. Off) position.

When I get back in town tomorrow, I'm going to pull the brake light lamps one at a time and see what happens.

Monty
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Past: '79 245, '91 240, '88 245. Current: '90 245, '83 245, '95 940

Oh, you are right, the center position is off or the smooch at the drive in setting! He is a good boy as he will not disturb the other movie attendees!

Now, we might know the real reason for the light being turned off!

Because, I see Art jumped in about the delay relay. I thought about it but I thought the heater insides cools off and turns the light off. But, it being on somehow or a door switch being stuck on, will work!
I did not any history on the relay. Just like other things, I might add!

I thought about the tail lights but I was thinking that the brake would have to be turn on to get power back there.

Phil

Monty,

You may have a delay off feature on the courtesy lights. It uses a bimetallic thermal delay element heated by a nichrome wire, and may have been an option back in 83, though standard in later years.

The heater in that delay relay can be stuck on, drawing about what you see. Look for an object about the size and shape of a fluorescent lamp starter, clipped to the pedal frame above your lap. Many many posts about this.




--
Art Benstein near Baltimore

GREAT TRUTHS THAT LITTLE CHILDREN HAVE LEARNED:
5) You can't trust dogs to watch your food.

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

CB,

What did you want me to see with the attached link? Is the wiring diagram different than the one in my Bentley manual?

Monty
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Past: '79 245, '91 240, '88 245. Current: '90 245, '83 245, '95 940

The link he gave is for scanned Volvo Green books. The wiring diagrams are much more extensive and there is a separate page for each system. for the more complex cars, 760/940/960 they are an absolute necessity while the Bentley is usually adequate for a 240 (no bentley for the later cars).

It would be good if they were the real deal Green Book diagrams, but the one linked here is a Mitchell. Assumed to be accurate but hard on the eyes.

--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

Disconnecting parts is definately the way to find the culprit.
That is a rather suspect drain though, in that a bulb would pull way more current than that, and light up as well.
Could be the switch is not going to off completely and allowing some current through, but another thing to look at .
Check a wiring diagram to see everything which is on that fuse (unless you did that already), there are sometimes other things other than those mentioned on the fuse panel.