w124 no heater or instrument cluster

[Greenthing]

Hello, I bought an e300 recently, the heater blower motor has only worked twice, both times for about a minute or two and or weeks now hasn`t worked at all. After checking the reciepts which came with it I found one which shows a new blower motor was fitted a couple of years ago. I started having a poke around, checking the plug to the motor, fiddled with the brushes incase they`d got stuck, sprayed a little lube on them. Then I followed the cable back to the bulk head behind the relays/fuses, where they were plugged into a small unit which looks like a small cage.
Can anyone tell me what this is?
I`ve read elsewhere about the flat blade fuse mounted to the top of the suspension turret on the nearside but that looks ok. I haven`t put a multimeter on it yet. can anyone shed any light as to why it isn`t working please?
Apart from that, I decided to pull out one of the relays behind the fuse box just out of curiosity,( approx 3"x1 1/4"x2" in size with a number of round pins on the bottom, on ebay it`s described as either a flasher relay or light control unit relay ), after putting it back I now have no fuel gauge, oil pressure gauge, temp gauge or rev counter and, there is a constant mid-high pitch tone coming from it unless i put the indicators on.
Can anyone tell me what`s going on please.

 

[Greenthing]

I`ve sorted the instrument cluster and humming relay issue, it was fuse number 5, but still no blower motor.

 

[WDB124066]

If the motor has been replaced may be look at the dash switch? Metal has been known to rain out of them from time to time, usually with an accompanying stiffening of its operation. Can you run a test through it...?

 

[Greenthing]

The switch is quite stiff. I`m able to run a test if I understand how. I have wired an immobiliser into a vehicle before but only with clear instruction, so if you`re able to explain how as if you were talking to an idiot I`ll have a go.
Thanks for the reply.

 

[WDB124066]

Right, you shouldn't have a stiff switch mate, it should slide nice and smooth between the fan speeds.

I know how to hit things with hammers only, when I was younger they would not let me near the sparks, hence electrickerty became just that - sorry.

I was hoping computers would be a passing phase, and I am still hoping walkytalky phones will be.

Maybe turn the switch and see if you get any sparks from the motor wires...

More people who haven't learn't to use hammers properly should be along shortly to help us come up with a test using an electric gauge.

If they are stiff they can be lubed but this is only a temp fix, I am due to replace mine I haven't priced it yet but FWIW can you get one from a breaker or borrow one if a new one is too much from The Dealership?

 

[brucemillar]

I was hoping computers would be a passing phase, and I am still hoping walkie talkies will be?

Walkie Talkies were designed by women to stop men shouting. Stick to shouting and save money. Mobile phones perform a similar function. The further away the caller is? The louder I have to shout my replies.

The switches may benefit from a good spray of electrical contact/switch cleaner and NOT WD40 please. WD40 my well be what is gunking up (technical term) the switch to start with. Contact cleaner will wash any gunk out the guts of the switch.




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[toolman1954]

Bruce is on the mark with his warning about WD40, as a releasing spray for seized bolts its o.k. (although there are better substances in my opinion) and it will cure a squeaky door hinge.
Servisol Super 10 is what you need....... Maplins used to sell it, but now you will have to search Ebay or Amazon for the cheapest price. like many things, postal charges exacerbate the price of an item. Buy 2 and flog 1 to a friend.

Steve.

 

[Greenthing]

Ok I`ll give that a try. I`ve found some info on how it comes apart so will give it a go soon. I`ll have to get myself a manual. If you have any tips or can tell me what type of bulbs are used behind the switches, that would be good as one side doesn`t light up properly. Also one of the air flow vents at the end of the dash isn`t lighting up, would that be the same bulb?

 

[WDB124066]

Yes and they are available from the Dealer for next to nothing, make sure you get the right power rating, more powerful ones are brighter but hotter too and will melt the plastic, stick with original if in doubt.

 

[Deadly Dave]

Lube on the carbon brushes will burn out the motor !!!

 

[grober]

If the "cage" looks like this

its a series of resistors to control heater blower speeds

 

[Greenthing]

I`ve tried putting lube on the brushes. If it dries up later I`ll try getting into the switch and cleaning that up.

Yes that`s what I meant by cage. Are these known to fail and how would I go about testing it?

 

[Greenthing]

Thanks for all the advice so far.
Regarding the servisol super 10, I can`t seem to find anywhere to buy it on the high street. Ordering on line isn`t a problem and I wouldn`t use wd40 penetrating oil to clean elctrical components but I did find this on the screwfix website `wd 40 specialist contact cleaner` designed for this purpose. I`ve never come accross it before and presume this isn`t what you were warning me against. Has anyone tried this?

 

[grober]

I`ve tried putting lube on the brushes. If it dries up later I`ll try getting into the switch and cleaning that up.

Yes that`s what I meant by cage. Are these known to fail and how would I go about testing it?

This is a good primer.
Blower motor doesn't work — Ricks Free Auto Repair Advice

sorry haven't got an MB circuit diagram to hand but I believe its a switched live earthed motor set up

 

[wrdcc01]

The caged resistors controlling the blower speed on the bulkhead are connected by a 6 pin plug behind the instrument cluster and on a couple of my previous 124s have melted and fallen apart. Worth looking at if you are ok pulling the cluster.
The backlights for the switches and air outlets are all T5 lamps but if you change to LED go for low profile ones that allow more light spread like these I use. They also don't need to be altered to fit properly.
10Pcs T5 12V Wedge LED Light Car Dashboard DASH Gauge Lamp Bulb | eBay