Relay number for hardtop.

[BuxtonZ3Guy]

Hello chaps,

Does anybody know which relay is used for the hardtop in a 2001 Z3, 3 Litre Roadster? I can't seem to get a definitive answer from the archive.

Cheers.

Andy.

 

[Duncodin]

I assume you mean for the heated rear window?

Y'know. That confused me too. I have a pre face lift and, to me at least, it looked like the switch was real heavy duty and is wired directly to the window so all the current through the switch without a relay.

But the the facelift switch is a much lighter thing. Wires and connectors don't look chunky enough to carry all the current so would likely be a relay in there somewhere. But looking at wiring diagrams I didn't see one.

I don't have a facelift so can't look. But if you look under the back of the centre console is there a relay floating about down there below the switch?

 

[BuxtonZ3Guy]

Yep. It's the heated rear window in the hardtop. My car is a facelift. The heated screen switch lights up when you press it. There is no relay behind the switch or wiring that would accept one.

 

[Duncodin]

When i bought my hardtop it came with a facelift switch. The wrong one for my car. So I looked at wiring diagrams for both pre and post facelift and couldn't see a separate relay in the diagram. But I feel the facelift version should have one.

Are you asking because your heater doesn't work? On the left hand roof mounting clamp there's a thing with wires going to it. When the roof is clamped down it closes the circuit between car and window element. Is there power in the wiring by the mounting pin/bracket? Does the circuit close when the roof is clamped down?

There's other's here on the forum more knowledgeable than I am. So maybe somebody will.come with better things to look for

 

[BuxtonZ3Guy]

The heated screen in the hardtop is not working. Yes, my car has all the wiring for the heated screen in the hardtop. My car has an electric roof so I bought the bits so I could break the electrical connection for the roof and fit the connections for the heated screen. I just need a definitive answer concerning the relay. Hopefully someone on here with a bit more experience can help us with this.

 

[Nodzed]

My car has an electric roof so I bought the bits so I could break the electrical connection for the roof and fit the connections for the heated screen.

Not sure I understand this, the connectors to add the heated rear screen should be part of the fixing kit, on the passenger side bracket, at least everyone I have fitted this has been the case.

 

[Duncodin]

I'm puzzled as well.

@BuxtonZ3Guy what bits did you buy. Your comment about buying something to break the electical connection for the roof doesn't make sense. Show us what you bought.

 

[BuxtonZ3Guy]

Not sure I understand this, the connectors to add the heated rear screen should be part of the fixing kit, on the passenger side bracket, at least everyone I have fitted this has been the case.

Yep. That's what I did. All done via the fixing kit. Sorry if the previous post was confusing.

 

[Duncodin]

This page has few diagrams for different years.

z3 FuseBox/Relays

The diagram for one year says it's relay 15 but other years it's relay 6. I read somebody else saying it's 10.

Some of the confusion between 15 or 10 might be down to the way they're numbered. Some diagrams show relays 10 - 15 numbered left to right while others show numbered right to left.

Here's another

That one also suggests R15 is the one but shows it at the other end of the row. I guess you need to check what you've got and how they're numbered.

 

[NZ00Z3]

Yes there is a rear window defogger unloader relay. All Z3's have the relay and they are all installed at the factory.

Located in the front fuse box. The location depends on the year and model of Z3. The items location list under the fuse box lid should tell you the location for your car.

Alternatively, find the wiring diagrams for your car (they are all in the "Resources" section of this forum, both North American and GB), get the number of the relay (K9 etc) and use the parts location diagrams in the back of the wiring diagrams to locate it.