Help Negative Switching

[Maverick]

Trying to be smart and got a remote relay switch for the rear window, but the rear window relay is negative switched, and the remote relay is suppling positive.
Does anyone have any ideas how I can get a positive feed to switch a negative, cause I can't.
The only thing I can think off is to wire direct to the motor, but this will then bypass all the safty features of the rear window relay.

[Maverick]

OK just to let you know wiring direct to the motor doesn't work either.

[dave.j.robbo]

Trying to be smart and got a remote relay switch for the rear window, but the rear window relay is negative switched, and the remote relay is suppling positive.
Does anyone have any ideas how I can get a positive feed to switch a negative, cause I can't.
The only thing I can think off is to wire direct to the motor, but this will then bypass all the safty features of the rear window relay.

You say the relay is supplying a positive 12V. Where is this coming from? Is it integral to the unit, or is there a separate feed to go through the contacts?

If it's separate, then what you need to do is earth the lead that is currently at 12V.

If it's integral, you need to use the 12V output to switch another relay, which can be wired to switch 0V.

Hope that makes sense!!

[MattF]

If it's separate, then what you need to do is earth the lead that is currently at 12V.
Hope that makes sense!!

Just in case the OP is a bit sketchy on electrics, that might have been
better phrased as 'disconnect from 12V then earth the lead'. Visions of
wire in meltdown mode



Matt

[spans]

Hi, I thought that the relay box, changed polarity according to the desired direction, the motor is supplied a positive and neg on one direction for up, and the opposite configuration for down,as the relay box inside the rear left of the car has two relays.

You could supply the positive out from your remote relay to the correct side, and you have to relay the neg as well, but I am unsure about what would happen if you press the button as well as the remote!
as you could have a direct positive to ground, and those tracks on the relay board ain't all that thick.

[Maverick]

Well I had them working until I found that the funny noise I've been hearing and the jerk in the window movement, is in fact the worm gear going FUBAR. Begging email sent to TonyN.

[dave.j.robbo]

Just in case the OP is a bit sketchy on electrics, that might have been
better phrased as 'disconnect from 12V then earth the lead'. Visions of
wire in meltdown mode



Matt

Good point!!!

[Maverick]

In my car it's not a case of wire melt down, more wire overload. Soon I'll have to start running the wires along the outside of the car, as I'm running out of room inside!!

[kitesurf_phil]

Well I had them working until I found that the funny noise I've been hearing and the jerk in the window movement, is in fact the worm gear going FUBAR. Begging email sent to TonyN.

That jerky movement is caused by the glue that bonds the steel wheel to the nylon cog, inside the gearbox, breaking down. I Araldited mine and it worked ok for a couple of days. I am going to strip it again and bolt through the rubber wheel direct to the metal wheel. It will all make sense when you have it in pieces (deep joy).

[MattF]

In my car it's not a case of wire melt down, more wire overload. Soon I'll have to start running the wires along the outside of the car, as I'm running out of room inside!!

Rubber hose, through chassis from back to underneath drivers
door where it can exit where the plastic blanking plates are in the
chassis rail, then run through bottom of wheel arch into engine bay.
Rubber hose is just more chaff resistant and cushiony than conduit.

Not that I've already gone down this route, BTW.


Matt