Voltage loss, fuse to heater plug

John Halliwell said:

Hi,

I have a problem with my 1988 90 (200tdi disco) heater blower. It was intermittent last week and has now stopped all together.

I have searched and searched over several days for existing posts, but i can't find one with quite the exact same problem. This is following on from some limited investigating already.

I have 'hotwired' the fan directly from the battery for a few seconds to test that the motor works and it does. I have looked at the wiring diagrams and following them i have checked and i have over 12v at the fan fuse in the cab. But at the heater plug, i am only getting 5.8v. This is with the switch set to blow at max.

I believe that the circuit runs from the battery via fuses to the heater then is controlled by the resistor on the earth side to control the fan speed. So i believe that i should have 12v at the heater plug? I have also read on other forum posts from people that have had heater problems that they get 12v at the pug (so obviously they have had different issues)

So does it sound like i am losing some voltage between the fuse and the plug?

Or should i just give up and phone an auto electrician!

Cheers.
John.

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doriz said:

I wouldn’t phone a leccy. Can you bypass the daft speed setting switch on the side of the binnacle likely that’s gone rusty and the connection to complete the circuit is vagazzled.

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bluedog333 said:

This is what I have done on mine. I now have a on-off-on toggle switch for the heater, works lovely.

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John Halliwell said:

Solved.
Couldn't wait until weekend. I pulled the dash out on works car park and noticed a previously bodged repair to the wire that was a bit crusty. Cut the ends clean and re connected and the blower worked again.

I like the toggle switch idea. The low speed is a bit pointless anyway, and the lever switch is bad!

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doriz said:

1 speed is fine in my view you’ll want carpet next.

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bluedog333 said:

You may as well keep the low speed, I find myself using the high speed until the interior is nice and warm and then the low speed is good enough. Another good mod to do is to turn the lower blower vents upside down and swap passenger side to driver side. This way you’ll have nice warm air directed towards your body and not mainly to your feet!

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