Burning down the house!

[willw]

Hi All,

This morning the temperature dropped in Austin, Tx. into the 50's from
the usual 80-90's at this time of year. Being a little chilly, I spun the
wheel on the climate control from its usual full cold position to about
half way to the hot setting. After a few minutes I began to smell a
very strong burning smell coming from the car. I turned the climate
control back to full cold, and then turned it off, and after a few minutes
the burning smell went away.

When I got the car it had tons of leaf litter between the 2 firewalls. I
cleaned this crud out and vacuumed out as much as possible. I have
good air flow through the vents in AC mode. I imagine that leaf crud
could have gotten into air system, but how would it get how enough
to smell like it was burning. I would have thought I would smell mold
or rot smell if that was the problem. The heater isn't electric, its water
based right? And I don't think hot water would give me a burning smell.

Any ideas on what could be causing this?
1984 300SD Federal model.

Thanks!
Will W

[Simpler=Better]

Drop the passenger's kick panel, and then the blower-it should be fairly easy to get in there. Then complete your vacuuming frenzy

[sleepstar]

i used the heater in my 300d for the first time all year last week or so and i had the same smell. i thought i had a sticking brake caliper for a minute. it went away the next time i used the heater.

[Travis_k]

There is a resistor under the brake booster where it will get covered in leaves and can start a fire. There was a post about it on here just a couple weeks ago.

[pawoSD]

The blower resister is used year round as the blower operates in all conditions. The smell was likely the climate control board burning from a stalled out auxiliary water pump drawing too much current. It is located near the battery behind the false firewall under some hoses by the water/mono-valve.

[Silber Adler]

Ouch some bad problems for no real good reason, except age.

Hopefully it won't be that bad.

[vstech]

if the blower was in the low speed position, for heat, but high all the time for a/c or ventilation, then the fire would only happen in heat.

the resistor only gets hot in low speeds...

[sleepstar]

there was a member here who sold kits for the aux water pump that had the electrical connections and an inline fuse to prevent overloading like that. i have one installed in my car.

[charmalu]

Did it smell like electrical fire or leaves?

The auxillary water pump is not fused, and if it shorts out, it can short out the climate control unit and start a under dash fire. It is recommended to add a 1 amp fuse to the wire going to the aux water pump.

http://www.peachparts.com/shopforum/diesel-discussion/241899-i-lost-all-electrical-fire-high-up-dash.html


Charlie

[chasinthesun]

In a plug in heater in your home Just a good amount of dust can burn and give you that smell,I imagine a compost of leaf debree would create 10 times that burnt poop er rie.

[Tanksowner]

Originally Posted by charmalu

Did it smell like electrical fire or leaves?

The auxillary water pump is not fused, and if it shorts out, it can short out the climate control unit and start a under dash fire. It is recommended to add a 1 amp fuse to the wire going to the aux water pump.

http://www.peachparts.com/shopforum/diesel-discussion/241899-i-lost-all-electrical-fire-high-up-dash.html


Charlie

Exactly why I bought a kit from DeliveryValve to have a midget fuse in line with the aux pump. Peace of mind.