1990 BMW E30 325i - AC Aux Fan Temperature Switch Connector and Wiring

[chomowitz]

I have a 1990 BMW E30 325i 4dr Sedan. The AC Aux Fan Temperature Switch on my radiator has wiring and a connector that are both deteriorated. I have "taped and glued" things so it works, though I am suspicious of the High Temp connection.

I would like to get a replacement connector (part number 61131378410), which I can find, but I cannot identify what parts I need to put new terminals on the wiring that go into the connector. I'm pretty sure the terminals crimp onto the wires and have some kind of a collar that you put onto the wire before crimping. After crimping the assembled terminals fits into the connector housing (I think you pull them back into the housing after assembly, but I could be wrong). Can someone help me find the parts I need and how I might assemble them?

BTW ... I have found a few used pigtails on eBay, but they are limited and the best looking ones only have 1" to 1 1/2" of wiring hanging on them. I could try them, but I want to evaluate getting new parts and rewiring the connection first.

Thanks in advance for your time and support ...

[richardodn]

They are available, but they will not match colors. They're all part of the BMW 2.5mm connector family. Here's a link to a listing for the pigtails and replacement pins. https://www.realoem.com/bmw/enUS/sho...diagId=61_2489

That particular connector takes the right angle watertight style so you can't get just the pin; you'll need a pigtail with connector. Wiring diagrams say that the aux temp sensor connector has .75 mm2 wires. That means it's

03

Snap-in receptacle 2.5 watertight

0,5-1,0 MM²

X

61130007445

If I remember correctly, they'll all be green with black stripe.

[chomowitz]

Hey richardodn ... Thanks for the info. If I get three of these 61130007445 pigtails, will they seat into a new 61131378410 plug housing? It's hard to tell from the part pictures if that is true. My deteriorated housing and connections that I "taped and glued" together aren't much help in answering this.

Also, how did you track down the specifics of this connector assembly? Your response referred to "Wiring diagrams". Can you share the wiring diagram link or information.

Again ... Thanks! This information is extremely helpful.

[richardodn]

Yes. The connector will snap close. I also recommend using a minimal amount of the pigtail, 2-3", so you don't have to chase the wire to find out what color it is.

Like anyone. I had to replace it once too. I've also spent a lot of time browsing the parts catalog.

http://wedophones.com/BMWManualsLead.htm

[chomowitz]

Thanks for the response. I'll follow up and get the pigtails (3x) and the plug housing.

One more question ... Regarding the Dual Temperature switch this plug assembly goes into ... I am not sure if mine is fully functional. The aux fan runs at the normal/low speed, but I don't know if the high speed temp works. I replaced the resistor on the high speed portion of the aux fan not long ago and it worked then (tested by applying 12v directly to the high speed lead). If I have to replace the dual temp switch, the standard one has trip points of 91 deg C/99 deg C. From my readings, some people suggest replacement with a unit that has trip points of 80 deg C/88 deg C. With your experience, do you have any thoughts on this issue? Your advice would be appreciated.

[superj]

Doesn't the high come on when the ac is turned on?

[richardodn]

Going with 80/88 switch is something you might do if you're going with an electric radiator fan. The idea being is it switches on a bit earlier. There's no need in a car with a mechanical fan. If you are having overheating problems with a mechanical fan, a cooler switch is just a mask for an underlying problem.

Fan comes at normal speed via the thermal switch and the normal speed fan relay. Normal speed passes through the resistor. To test, jumper the black and green/black wires together at the thermal switch. This should activate the K1 normal speed relay and in turn the fan. If it doesn't try tapping on the K1 relay and/or swapping the K1 and the K6 high speed fan relay. If it now comes on, replace the relay. If not, you'll need to check for voltage at both ends of the resistor.

Fan comes on at high speed when the switch hits the high limit. Also as superj said, when you turn the AC on. Turning the AC on is easiest way to test. You can also jumper black/brown to green/black at the switch. Again you can play with the relays if you don't get anything. The resistor is not in the high speed circuit.

[chomowitz]

Good info ... Thanks.

I'm confused though on the Aux Fan Speeds. In the 1990 BMW 325i Electrical Manual on diagram 6454-0 "AUXILIARY FAN", I interpret the circuit to show that when the AC Selector Switch is ON, it turns the K1 NORMAL SPEED RELAY ON and does nothing to the HIGH SPEED RELAY. If my interpretation is correct, the only thing that turns the K6 HIGH SPEED RELAY ON is if the DUAL TEMPERATURE SWITCH senses temperature above 99 deg C.

If I am wrong, that's okay, but can you help me understand your position that the AC CONTROL SWITCH ON position turns the AUX FAN ON at HIGH SPEED.

[superj]

That's odd. The diagram does say that

On my 89 325i, I ran using only the fan switch and the ac button. I took the clutch fan off one year to see what it felt like. If I pushed the ac button, the fan came one

[richardodn]

Apparently I was the confused one. It is indeed the normal speed relay. High speed is only in over-temp condition.

[chomowitz]

Thank you all for your valued contributions. I am going to order 3x 61130007445 right angle pigtails and a 61131378410 plug housing. That should allow me to fix my deteriorated connector on the dual temperature switch.