I would like to somehow get better light output for the 1992 Volvo 945T. The 91 240 has superior headlight performance but I don't know what the difference is.

I haven't paid attention to the new technologies. Is there a product that:
1. Is plug and play (no rewiring required)
2. Provides better light output than standard bulbs.
3. Doesn't mess up the bulb out relay

Note that the glass lenses are clean and not yellowed.

Any info appreciated.

Brian Mee
92 945T
91 240

Should you try to clean your reflectors, be very careful - you can easily destroy some reflectors.

A voltage check is OK, but it ic current that powers the lights.

So is checking the aim of the lights - If you trade regularly with a garage that can aim lights they may check your lights for a very low fee.

I had a 740 that had a headlight out, but showed voltage? When I checked the wire to it, I found that about a foot up the wire it had corroded to just one good strand.

Consider this - as bulbs age, they can deposit filament metal on the inside the bulb envelope - also age can cause dimming

Try Sylvania Bright Stars, they made a big improvement for me. Keep the old bulbs in the car for spares.

Bring your car to stage 1. Keep used ignition parts in the car - for instance you can check to see if your engine has spark by putting a used plug in one of the wires, instead of pulling a plug from the engine.

Also, consider unpluging all connectors and cleaning them, add dielectric grease when you put them back together - clean grounds as well. (use dielectric grease for your new headlights.) I did one connector every few days in case i had a problem with the process, I knew where to look.

"A voltage check is OK, but it ic current that powers the lights."

Ehm, no. Current and voltage cannot be seen separate from eachother.
And especially on incandescent halogen bulbs designed for 12 V, the rated output is at that particular voltage, which means that when the alternator is running and outputting, say 14 V, you get more power and thus more light (at the expense of lifespan).

Look at Ohm's Law describing the relationship between voltage, current and resistance, and you'll see a mulplier in there: V = I * R.
With a fixed resistance R, change V and I has no choice but to change as well.

Voltage drop in bad wiring and contacts can have a big impact on light output and shouldn't be disregarded out of hand as a possible cause of poor light output.

Now, LEDs are a different beast being run from current limited supplies. But still Ohm's Laws apply. There's just a control mechanism in place that isn't there on incandescent bulbs, and within certain limits the voltage may change without having an effect on the light output. Sadly where I live to this day, retrofit LED bulbs are not compliant with regulations in all but some very rare cases.
--
1992 245 Polar B200F M47

Grey 245 -

Did you read what happened in our 745?

I agree whole heartedly that both current and voltage are important - the other poster just suggested a voltage check. Not enough.

I submit to you that if a load is drawing its proper current in a good circuit, then the voltage has to be adequate.

I have e-codes and headlight relays installed on my 1994 944T. I'll rate the headlights as a 10 out of 10. The e-codes are genuine Volvo.



--
john

Before throwing money at the issue do a couple checks to see if what you have is working properly. Maybe its just an alignment problem.

1. Check that the cars are level, maybe the rear of one car is sagging a bit.

2. Park each car 20 feet from a wall, on flat ground, and measure the height of the light centers.

3. Buy an inexpensive multimeter and measure the voltage at the headlight connectors.

hi brian

there's an earlier thread about 940 LEDs- use the brick search engine.

direct swap leds are one solid option.
i did that and then went to e-code light conversion with leds with my 1993 940.
i've kept the headlights adjusted out of oncoming traffic and had no trouble with inspections or police.
now i'm using lasfit units for the 940 ecode headlights. $42 at ebay last summer.
Lasfit 9003 H4 HB2 LED Headlight Kit High-Low Beam 50W 6000K White LCplus Series
i forget if the sae bulb is the same, there will be a unit to fit your base.
they seem to be current limited devices and one draws more than the other.
the high and low beams don't converge on the same spot. maybe that can be adjusted out but i'm on vacation for playing with the car now.
it's close enough to forget.
i pulled the lamp baffles and got better light- easy to put back in if you want.
i rate them a 7 out of ten.
standard lights are maybe a 2 out of ten.
sae plastic lenses are worth changing. the tyc e-code units have great glass lenses but leave plenty to be desired with flimsy lamp adjusters and poor dealer support.

if you shop ebay there's a raft of offerings changing daily.
dealer specs vary far and wide from the truth and there are some absolutely incredible lies about power: 1500 (and more!) watt headlights ...very big liars out there. . buyer beware. some units are two big to fit. be sure the seller will pay for the return. verify with the dealer's fitment chart that it fits your car, and save screenshots.

if it's a dealer from offshore, all bets are off with warranties, ask me how i know.

bottom line, tinker with direct fit led's, you'll get better light, but expect
some problems. the good news is you can get a set of leds very cheap, the price has dropped enormously in the past decade. report back your findings.
leds keep getting better and cheaper. you'll have some fun when you find
the right leds and can see better at night.

bill

The condition of the reflector is very important. - 240 '86-'93 headlights suck (excuse my French) compared to the 4 round system on previous model years. I have a set I'll probably adapt to my '93 245V8. - Dave