Wiper motor problems

[Tuck2020]

Morning everyone

I've hit a snag on my sigma race car to road car transformation that is puzzling me a bit, if anyone has any wisdom to offer?
 

Ive acquired a new, tested working, wiper assembly. I figured that this would be one of the easier projects that I have undertaken, given that the connector was there, just waiting to be plugged in. One of the wires to the loom connector (orange) was broken, so I joined it with a crimp.

I'm getting nothing from the motor at all, and I'm going to start probing with the multimeter to see if I can figure it out. But more worrying, I blew a 15a fuse immediately, and then when I replaced it, with the ignition on I'm getting wisps of smoke from behind the switch, and from the motor itself. In addition, when I work the switch vigorously, the rev counter needle moves around. Do they share an earth, or does anyone have any thoughts as to what might be happening ?
 

many thanks 

[Jonathan Kay]

If you would like a copy of the wiring diagram please send me a Private Message with details of the Seven and your email address. NB there are at least three layouts of fuses and relays on Sigmas. At least one never appeared in an Assembly Guide.

"Standard" British wiring colours: Caterham usually adhered to these.

Jonathan

[Jonathan Kay]

First thoughts:

• With self-parking wipers there's a live feed to the motor even when the switch is OFF.

• On your car is the intermittent wipe function activated by a quick ON and OFF of the switch?

ª Yes, there's an earth post for the instruments at one end of the dash.

• Is the system voltage dropping when the rev counter misbehaves?

• There will be a reason why that wire was broken.

Jonathan

[Tuck2020]

Thanks.

I haven't done anything to the earthing point on the wiper bracket bolt except clean it up with a dremel to ensure good contact.

Intermittent wipe - not sure, it's not had them fitted in my ownership- I understand there's a module somewhere which controls this feature that's unreliable though? What does it look like?
 

I'll check the system voltage, but I was worried that just having the ignition on would burn something out.

I hear what your saying about the wire - it had a crimp on it, but looked like it has broken/been cut next to the crimp - I wonder why.

 

Thank you , as always, for your help. I had hoped this would be one of the easier projects!

[Tuck2020]

I'm intending to keep updating this in the hope that it may be of some use to others who encounter similar problems.

So far, I've checked continuity between the connections at the rear of the switch, and the connector which attaches to the park switch on the motor. All appears good. I've cleaned the connector pins and shined them up. I intend to check continuity across the switch but don't know what I'm looking for yet, more research needed!
 

As soon as I operate the switch with the ignition on, I'm blowing the 15a fuse. My current focus is a box attached to the bulkhead, like a cigarette box sized unit with a silver shroud. Could this be the fabled intermittent wipe box that I've read about? I can't find a picture on Google to check.If so, I've heard it's the source of issues. It appears to have wires coming out of it, one of which is terminated (black). Hmm.

The puzzle continues.

[Wrightpayne]

On my 98 car the intermittent box had a male and female loom plugs - to remove it I just unplugged it from the car loom and joined together the two plugs on the car loom. The intermittent box of electrickery simply 'intercepted' the wires to the wiper motor.

Have you checked cable colour continuity between the car loom and the new wiper motor in case the cables are in different locations in the plugs?

Ian

[Tuck2020]

Ian

Thats a good point, thank you, I'll check the colours.

[Jonathan Kay]

At least it's blowing the fuse consistently!

Does that happen if you've disconnected the wiper motor from the loom?

Jonathan

[Jonathan Kay]

I suggest identifying the layout of fuses and relays. 

You can probably do this from the factory documentation. But if not please add a photo.

...

Can you see the colour of the wires connected to the mystery silver box?

...

Please can you add a sketch of what colour wires are connected where on the switch.

Jonathan

 

[Mechanical Moz]

The box with the stainless steel cover will likely be the immobiliser.

https://www.toadalarm.com/product/sterling-excel-immobiliser/

[Tuck2020]

Thanks everyone, and apologies for the lack of replies and updates, family circumstances kept me away from the car and my computer for a few days. I have nothing further to report except that I bought a new switch whilst I was away as a lazy "quick fix" hope, but unfortunately it hasn't solved the problem.

Jonathan, I'd like to take you up on the offer of a wiring diagram please, I'll message you. Maybe once I understand the circuit a little more, I'll have some hope of diagnosing it!