I've got a parasitic drain on my battery to the tune of at least 250mA, and after pulling the fuses and testing for it I've concluded that it's primarily from the circuit routed through fuse #8, which lights up the interior of the car in various places, as well as powering the locks. This fuse connection, along with #10 (power windows, which I don't even have) have enough juice to light up a test LED with the key out of the ignition.

Anyways, 250mA is pretty high from what I hear, and I just don't know about tearing my poor car apart to find where it's shorting or whatever. Anyone got any ideas about common weak links in these circuits? Where to look? Something obvious I am overlooking? Just wondering.
Thanks fellas

I had a draw in our '95 855 base - I tracked it to the glove box light - removing the bulb did not cure the problem, but disconnecting the switch did!
--
'96 855R,'64 PV544 driver, '67 P1800 basket case, '72 Yamaha Rd400, '68 Honda 350-4, '12 XC70, the first 5 are mine, heh, heh, 525,000 miles put on 10 bricks James A Sousa

A "test LED" doesn't take much power at all to light. The normal drain of the clock, radio memory, and ECU nvram will light an LED easily.

But 250 mA is serious, and the most common reason is flaky insulation in the door's key switch or lock knob switch wires holding an actuator. The second most common reason is a faulty courtesy light delay relay under the steering column.

To isolate the central locking cause, disconnect a three-position connector above your left knee with red, black, and green wires. If the 250 mA drain persists, try removing the dome lamp delay relay -- looks like a fluorescent lamp starter with four spade terminals.

Beyond that, suspect any aftermarket radio/alarm/keyless gizmos not professionally installed.
--
Art Benstein near Baltimore

Ever wonder what the speed of lightning would be if it didn't zigzag?

I can't seem to find the dome lamp relay. Even after googling up a picture of a florescent lamp starter, I still cannot locate this. Which side of the steering column is it on, and is it closer to the dash or the firewall? The only things I could find in there besides the central locking relay and this other one (which hang out down by where my left foot rests) were the big round connector plug to the dash and a large blue box relay with a lot of wires leading to it, on the passenger side of the steering column. There are lots of connectors but few relays. Could it be somewhere else? The wiring harness appears to have been tinkered with by a previous owner, and going over the maintenance records I know that the wiring harness leading to the rear of the car had been rebuilt, so maybe this relay got moved somewhere, if that sounds possible...? I will also check the circuitry of the glove box light switch just to cover all my bases.

THANKS!

Yes, the silver can wears black clothing.

Above your left knee, clipped to the brake pedal frame, was where it would have originally been placed. I think. Some things change over the years, and I've never owned a 1986. Check the operation of your light to see if you have the upscale feature. And report on the true current being drawn by your unknown consumer and whether you isolated it to fuse 8 and which of the two green wires connected to fuse 8. Have you eliminated the central locking as I suggested?

http://www.brickboard.com/RWD/volvo/1498923/220/240/260/280/kill_fire.html

Do search on "delay relay" for more. The courtesy light is sometimes referred to as a "dome light," a holdover from the 50's.

--
Art Benstein near Baltimore

The taste of low quality lingers long after the satisfaction of low price.

With fuse 8 in there, my ammeter reads -0.28 amps at the negative battery terminal, steadily decreasing down to .20 after a few seconds. With that fuse out, I get a draw of around -50 on the 200mA setting (50mA I presume).

Anyway, I found the dome light relay, disconnected it, and found no change in the parasitic drain. However, the connector at fuse 8 with the DOUBLE GREEN wires is the one which is sucking down that 200mA. What are the double greens for?

Disconnecting the central locking had no effect on the ammeter reading.

thanks for keeping up with this

The decrease in current behavior is consistent with central locking. Each actuator has a positive temperature coefficient (PTC) thermistor in series with it for protection. Can you convince me you isolated the central locking?

Best I know, the double green feeds the central locking and the courtesy lamp delay. I know that for a 91. Oleseahorse separated them (snipped) to find his delay relay issue. Unfortunately, the wiring diagrams don't detail construction, so you benefit from others reporting their experience chasing the wires.

You may learn what they are for by observing what no longer works with them disconnected.
--
Art Benstein near Baltimore

May the forces of evil become confused on the way to your house.

Hi Mr. Geodonut,

As Mr. Benstein says: Probably about two or three years ago, I tracked down that current draw to a faulty courtesy relay by separating the double green. You'll need another spade or splice the green wire to put things back in order after diagnosis.

I trust you have the wiring diagram for fuse 8, but I wouldn't be surprised if that's still your prob.

Marty

There should be a sticker/decal in the inner face of the fusebox cover that tells you the circuits served by each fuse. My diagrams are for older cars but they say Fuse 8 serves interior lights, glovebox light, trunk light, clock, central locking, engine compartment light. You can rotate the switch on the trunk light to manually switch it off in case closing the trunk isn't doing it. Ditto engine light if there is one.

Now that you know Fuse 8 is feeding the drain circuit, you can remove it and jumper its terminals with your ammeter and stop disconnecting the battery. Open the glovebox...does ammeter increase by ~200mA?...glovebox switch is working. No change?...glovebox light was constantly on, so switch is faulty. Work through the circuits like this.

The interior light delay relay I pulled in the PnP yard was found inside a thin black rubber sleeve, clamped to a bracket on/near the brake pedal frame. It's 20mm diameter and 35mm long. In the one I have (my notes say it came from a 1988) the four wires going to its black plastic, 4-terminal connector are green, white-black, blue-black and brown. At their other end, the brown terminates in a small ring terminal and is the ground, and the others go to a 3-way connector. This sub-harness is about 30cm long, inside a black plastic sleeve.

This might help you locate it. If your car has one, disconnect it and see if this gives a major drop in current drain.


--
Bob: son's XC70, dtr's '94-940, my 81GL, 83-DL, 89-745(V8) and 98-S90. Also 77-MGB and some old motorcycles.

Hi,

You might not have the dome light delay relay. I think my 90 has one but my 92 does not.

Travis

I will do just that. This is exactly the type of information I was looking for.

Thanks a ton, and I will update after I do this tomorrow