E36 final stage resister replacement - anyone done it?

[MitchT]

I've just replaced the final stage resistor on my E36 (auto air con version). Thanks to being reasonably fit for my age and slim it was a relatively painless task. I say "relatively" as it was still a complete ballache to do. Anyway, when you install the replacement resistor there's some wiring with a plug on the end and the plug fits into a receptacle on the resistor and is held in place by two tabs which clip onto the receptacle. Try as I might I couldn't push the plug sufficiently far on for the tabs to clip into place - there's literally 0.5mm to go. It was equally hard getting it off the old one - seems the prongs on the resistor that fit into holes on the plug are a very tight fit. The connection is good but I'm wondering if it's a bad idea to have it not properly clipped on. Has anyone done this job and had more success getting plug fully inserted and the tabs to clip on?

Edited by MitchT on Saturday 26th December 17:36

[RUSSELLM]

I’d be surprised if the male pins on the resistor, would stop the female connector going on. The pins obviously need to be tight, and they’ll just open the female side up.

The female connector on the harness... Has it a secondary locking device for the pins ? If so, make sure it’s seated correctly.

[MitchT]

Not sure how else to describe it...

The mail pins are almost fully into the female connector holes. They're just such a tight fit that they're about 0.5mm short of being fully in which means that a couple of tabs which clip onto the resistor are not quite far on enough to clip into place. NB. The tabs have to be squeezed together to facilitate disconnection. The connection is good and the fit is so tight that I can't see it being a problem, but not being an expert on these things I don't want to leave it as it is if there's an danger of arcing in the connections and possible damage to the resistor or another part of the car's electrical system.

I found this pic online and have labelled it in case it helps...

[smack]

I did it on my E39 years ago, and it was a complete ballache, and required from memory I needed to a precision turn/rotate/maneuver that took me ages to get in with lots of swearing.

I guess on E36's it is just as tight.

[RUSSELLM]

The female connector... Have you a picture of it’s face (the female pins showing) ?

[MitchT]

This shows the cabling with the female connector and the resistor with the male connector.

[MitchT]

Here's a diagram I drew to try to articulate my scenario...

On the left...
How it should be, with the block housing the female "holes" fully into the outer shell of the receptacle that surrounds the pins on the male connector and the tabs correctly snapped into place.

On the right...
How it is, with the block housing the female "holes" about 0.5mm short of where it should be and and the tabs not quite snapped into place.

[RUSSELLM]

I was suspecting the connector’s ‘anti blackout’ (secondary locking device) wasn’t pushed home, but that type of connector doesn’t have one on the front.

It would be unusual for the pins to stop the connector going home properly.

The Three grooves that travel up the connector... I’d have a good look up there and see if there’s any debris. Poor moulding etc.

Automotive connector wise... I’m normally listening for the click as the connector goes home. But failing that, a light push/pull test. Obviously pulling on the connector, rather than the wires. If it doesn’t come off, I’d be inclined to leave it.

[MitchT]

The old one was very hard to get off. With the tabs squeezed together I had to wriggle it about a lot to free it. Similarly, the new one was very hard to push home and I had to wriggle it a lot to free it when I couldn't get it to go that last 0.5mm for the tabs to clip on, before examining it and trying again, so I suspect it's perfectly secure. I just wondered if anyone who knows better than me would know if that last 0.5mm is likely to have any bearing on its longevity or safety. If not I'll probably just leave it as the fan motor works properly again now.

[helix402]

What make is the new fsr? I only fit BMW ones as I’ve seen too many no gen ones fail prematurely.

[MitchT]

This is it...
https://www.eurocarparts.com/p/eis-heater-fan-resi...

There were much cheaper ones on eBay, etc., but I don't fancy sticking a cheapo electrical component in my P&J, if the consequences I've seen reported of cheap phone chargers are anything to go by. Hopefully I'm right to have more confidence in the reassuringly expensive product that I bought.

[LunarOne]

I did it myself on my e46 Coupe. I took the seat out so that I could lie on the floor of the car, without realising it would cause the airbag fault light to come on. Then it still took me hours to get the old one out and the new one in. Not a job I'd like to repeat. I then had to buy an airbag reset tool to make my airbag system work again after putting the seat back in!

[Collectingbrass]

It could be that the pins are slightly too long. That said, when I did mine, it went back together again properly (eventually). I'd be tempted to have another go, maybe with some contact cleaner as some "lube"

[MitchT]

I'm thinking it's most likely that the shell around the male pins fits very tightly around the housing that contains the female holes. The reason I think this is because the old unit was very difficult to get out. I will give it another go as I'd prefer it to be in properly and I was so worn down by the time I got as far as pushing the new one in I probably didn't have the strength left that I will if I give it another go another day.