W114 indicators flash too quickly in cold weather

[Canned Benz]

Hi,

My indictors flash too quick in cold weather. Colder it is, quicker they flash. As the car warms up the indicators gradually slow down to normal speed.

All the bulbs work. I wire wooled all 4 bulb holders but no joy. Any help would be much appreciated.

 

[stwat]

Hi.

It sounds like a faulty relay.

 

[grober]

Here's how a hot wire flasher unit works. As you can see the timing is set by the current flowing through the hot wire + ballast resistor value and the strength of the spring - this will be influenced by the ambient temperature/age hence the change in timing.

 

[Canned Benz]

Cheers, thats really useful stuff. I'll order one up.

 

[Ted]

The fl5!! Now there's a blast from the past!!

Pretty sure that it isn't a hot wire unit on this model, but I would still be looking at the flasher unit. I also think that the flasher unit on this runs the hazards as well so the markings would be something like 2(4)x21w

He he fl5. We'll be talking about the advantages of the rb106 over the rb340 next

 

[Oneilly]

I thought that just meant they were shivering!

 

[grober]

Flasher Relay W115 W114 - PeachParts Mercedes ShopForum

or try this site

http://www.currentcare.co.uk/Products/flasher-units/12v-electronic-flasher-unit-01-020.html

 

[219]

I always thought the Merc ones were based on bimetallic strips rather than 'hot wires' ?

The flasher units of that era did indeed also operate the hazard warning lights ( my dad's W115 , bought new in 1970 , was the first car I saw with hazard lights and they were a novelty back then ) . The flasher unit on these cars is behind the hazard light pull switch down by the ashtray .

It might be worth cleaning up contacts and checking the wattages of the lamps are correct . Just as when one lamp is out , anything which reduces the load in the circuit ( less current flowing ) can affect the rate of expansion of the strip and thus flash rate . A bad earth somewhere could be the problem .

Also check your system voltage with the car running , low battery/duff alternator could be an issue .

 

[Ted]

A little tip on these older Mercedes, the indicator circuit runs through the hazard warning switch. Sometimes the indicators can stop working completely due to a bad contact within this switch.
Pulling the hazard warning switch on/off a few times will clean the contacts and get the indicators working again.

 

[Canned Benz]

I'm sure it's the relay/hazard unit now. Took it out on a frosty morning when it was flashing so quick it was almost constant. After warming up inside the house for 5 mins plugged it back in and it was normal speed. Got quoted £92.00+VAT by MB.

 

[grober]

I refer you back to post #7 for cheaper alternatives. what was the part no/make on the unit? try keying that into GOOGLE and see what comes up?