headlight relay - 240

I have recently been driving more at night than I have in quite some
time. While I do use my headlights in daylight quite often, this
problem would not have shown in daytime. Over the last few night
drives, after the headlights have been on for about 25 minutes, they
begin to flicker. Not fully off and on, but enough to be easily
visible. I tried turning the headlight switch off and on a few times,
and flashing the high beams, but the problem is so intermittent and
happens so seldom that it is difficult to tell the source of the
problem using that method.

I finally worked on the problem this morning (hard to remember to do
it- it's too dark and late to work on at night when I get home, and I
don't see tem flicker during the day and so I forget). I first
thought, "maybe a dirty fuse," but there are no fuses for the
headlights. Next logical step 9and the easiest) was the headlight
relay. Easily found without a shop manual by flashing the high beams
on and off a few times. It is located right next to, and behind the
battery on the inside of the fender well. I removed it and pried the
case off by bending the little tabs back, and found that the contacts
were arced more than I would like and had a bit of carbon on them.
After cleaning the contacts up I also cleaned the spade connectors on
the base of the relay and applied a bit of silicone dielectric grease.
haven't driven it for any length of time yet, but from the looks of
things, that was the solution.

On a side note, the workings inside the relay are a thing to behold!
__ __
Randy & \ \/ /alerie's
\__/olvos
'90 245 Estate - '93 965 Estate
"Shelby" & "Kate"

 

That's the high/low selection relay, there's another headlight relay
behind the dash, location depends on the year, but I've replaced two
that had oxidized and melted down the connector, had to replace the
connector as well. They're the small cube shaped 30A Bosch relays with
the standard 5 pin plug. Next time I find one burned up like that I'll
replace it with two in parallel.

 

Thanks, James... I will search out that one and check it as well. I
think I have a spare from the Pick 'n Pull..

I forget to mention two things;

1- the main problem I found with the high/low relay was that they have
two internal "arms" which are extensions of the two output spade
terminals. These are each held in place on the plastic base with a
single, small copper rivet. One had become a bit loose, so I reset the
rivet.

2- when replacing the large Phillips head screw that holds the support
bracket, be sure to replace the ground wire for the left front turn
indicator and the parking lamp. :-/

__ __
Randy & \ \/ /alerie's
\__/olvos
'90 245 Estate - '93 965 Estate
"Shelby" & "Kate"

 

Greetings Randy,
When I had a 240 decided the headlights weren't bright enough, so put in
higher wattage bulbs. Fantastic, no issues with seeing, except sometime a
similar issue as to yours developed. It was only after an hour and 1/2 on
the highway that I started smelling a burning smell in the dash and could
not find it. Discovered after investigating that the light switch itself
had got too hot and between the spade connector bits sticking up, it had
cracked between different ones and they were now a bit loose and this was
the source of the problem.

Went to volvo for a new switch, they said that this issue was not uncommon
if wrong size headlights had been fitted. The price was too high, went to
Import Advantage in Brisbane and got exactly the same part, same part number
(bosch if I recall right) for a fraction of what Volvo wanted me to pay.

Short story - if it's not the relay, could be the light switch. If the
light switch you may be able to source from Bosch for much less.

Jeff

 

This is a common problem, it depends on the year though, the earlier
240s run the headlight power directly through the switch, I think the
later ones run it through the relay. The factory wiring is barely
adequate, if you want to run higher power lamps, you have to add relays
under the hood and rewire the lights to run from those. I did that on my
740, with fuse holders coming right off the alternator feeding relays
for high and low beams. The lights are brighter even with stock bulbs,
less drop in the heavier wiring.

 

My '83 recently had a similar burning smell, along with some interesting
electrical type sizzling sounds...

http://home.pacbell.net/clayt/08102314380_1.jpg

 

That looks a little familiar, I'm assuming it smells the same as mine did.
LOL
Jeff