Heater blower relay/switch

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Dyane425
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Heater blower relay/switch

Post by Dyane425 »

I have a 1989 G reg BX 19 RD Hatchback RHD manual, non aircon. The heater blower was not working. My mechanic tested the fan motor, and voltage was reaching the motor. A new control unit has been fitted. Since then, the blast of air steadily increases up to about ¾ towards the maximum on the dial, then cuts out. I can hear a click (is this the relay or the switch?) when turning the dial from the off position. The Haynes manual specifies that the relay is to the right of the steering bracket (having taken off the dash trim), but did not say exactly where, so I could not locate it. Does anyone have the part number/amperage/colour of the relay, and where exactly is it located? How do I access the switch, and what part number for the switch?
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electrokid
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Re: Heater blower relay/switch

Post by electrokid »

Welcome to BXClub :D

If you can hear a click in the area of the steering column when moving the heater blower control through the last few degrees where the fan stops running, then the 'mod' is probably done but if not then have a read through this lot...

http://www.bxclub.co.uk/forum/viewtopic.php?f=15&t=5515

which may tell you the relay type as well - it's the simplest of all car relays - a 'basic' relay if you will - I'm sure a 30 amp relay will do the job ok.
1992 BX19 TGD estate 228K Rusty - SORNed
2002 C5 HDi SX estate
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mat_fenwick
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Re: Heater blower relay/switch

Post by mat_fenwick »

It's a 5 pin changeover relay, mounted to the steering column support. It's unlikely to be the relay at fault, especially as you can seemingly hear it clicking! The 'switch' which operates the relay is part of the tracks on the control PCB, but if the relay is clicking that proves it's OK. A look at a wiring diagram (sorry, I can't remember it off hand) should show what part of the circuit could be at fault.
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1993 1.9 TZD Turbo Estate
1996 3.9 V8 Discovery
1993 VW LT35 campervan
1985 Hyundai Stellar V8
2016 Hyundai iLoad
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electrokid
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Re: Heater blower relay/switch

Post by electrokid »

but if the relay is clicking that proves it's OK.
Usually - but not always Mat - my relay failed 6 months after I did the mod. If the contacts arc at all then it's only a matter of time before the heat melts the plastic and the relay contact moves far enough for it to be open circuit. My relay had a scorch mark next to one of the pins - unusual, but it happens.
1992 BX19 TGD estate 228K Rusty - SORNed
2002 C5 HDi SX estate
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mat_fenwick
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Re: Heater blower relay/switch

Post by mat_fenwick »

Ah - what I meant was that if the relay is clicking it proves that the 'switch' part of of the circuit on the control wiper is OK. You're right though, just because a relay is clicking doesn't mean it's passing current but does prove the control side of the circuit.
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1993 1.9 TZD Turbo Estate
1996 3.9 V8 Discovery
1993 VW LT35 campervan
1985 Hyundai Stellar V8
2016 Hyundai iLoad
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electrokid
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Re: Heater blower relay/switch

Post by electrokid »

Yes indeed - if it clicks then the circuit that drives it is functioning ok.

As to its location I've seen a number of descriptions of where it's supposed to be, mostly 'somewhere to the right of the steering column' which is indeed where I found mine - but not bolted to anything - it was just dangling on the end of its wiring.

I saw no reason to change that :lol:
1992 BX19 TGD estate 228K Rusty - SORNed
2002 C5 HDi SX estate
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