My doors alarm LED pins never work but every other thing else work prefectly. Recently, I took the door card off and took a look at the Alarm LED Impulse Sender, the part no. on it is 928.637.237.00. so I purchased 2 new Impulse senders (928.637.237.00), installed them and still both doors pin don't light up.

I am wondering if this (928.637.237.00) is for 1991 S4. I did some research and the sender part no. for 89-91 should be 928.637.137.00

Is there any different between 928.637.137.00 and 928.637.237.00 ?
Are they interchangable?

Thanks.

 

89 to 91 = 928 637 137 00
92 to 95 = 928 637 237 00

Do not know why there would be a difference but there is. Two separate part numbers and both parts readily available.

Alarm Control SS to the same number 89 to 95

You probably have something else going on.

 

Now you have the impulse senders (regardless of correct year) one thing you can do at least is test the pins.

The pins just unscrew from the doors. If you connect an impulse sender to a little 9V battery with the pin sitting in the coil it should pulse (reverse connections if it doesn't).

If it doesn't flash either way round then the LED or coil in the pin is bad. Having said that it's unlikely both pin leds have failed but you never know!

My pins don't flash either so I picked up a pulse sender on ebay to test them out of the car - they're both OK so next thing to check is the alarm unit under seat which sends out power to the impulse senders.

 

Thanks for your advices. Appreciated.
I had tried to connect the both doors' impulse sender with 12v with the sender and the pin in the doors, no light at all for both doors. ( Can I remove the pin without taking the door card? If I can, I wnat to test it again on the table).
I also had tried to use a multimeter to test if there is any voltage to the impulse sender from the control unit once after I had locked the car with key, there seems no voltage send out from the control unit neither.

I purchased this S4 used a year ago and the pin never light up after locking, all other functions are working fine. Thanks a lot.

 

It sounds like you must have removed the cards to connect to exising senders?

The door pins must be easiest parts to remove on entire car luckily! They just unscrew as base is threaded

 

Ok, finally I got time to further investigate this door alarm LED Impulse Sender issue.
There are 2 kinds of impulse senders:
89 to 91 = 928 637 137 00
92 to 95 = 928 637 237 00

My S4 is a 1991 and it supposes to use the 928 637 137 00. But the one installed in my car was
928 637 237 00 so I purchase both sets of senders. Here are the different of these senders.





(The 928 637 137 00 has some sort of electronics inside)

When I apply 9v from a battery to the senders over the pin, I only can get light up when I was using 928 637 237 00.

So I am quite confuse and don't know which one I should use.
Also, I had found 2 wires (one is brown-yellow, another is black) which maybe is the alarm trigger wires to the original radio. What should I do with these 2 wires? Ground them both? My car has a aftermarket radio right now.

Thank you.

 

Kevin did you fit the 137 00 to the car? Did it work?

 

Yes, I did but it did not work. I was thinking that the problem must be those trigger wires so I had tried to ground them both, ground each one at a time but nothing works.

All other things else like the power locks, alarm works perfectly. Just can't get those pins light up.

 

The impulse senders are driven by signal from alarm unit under driver seat. These units come up regularly on eBay and used ones available from usual vendors - not expensive.

I would get hold of one or borrow known good one from another owner, and see if that fixes LED issue.

 

I finally got another 928 618 260 00 alarm control unit from ebay. Replaced mine but still no LED light.
Here are the current situation:
- I had installed different Impulse Senders (928 637 137 00/ 928 637 237 00) on each door just in case I installed the wrong one.
- I had tested the Led light pin and it is working fine.
- All locking and alarm functions are working properly.
but still no light at the pins.

What should I check next? Thank you for your advice in advance.

 

Have you checked the continuity of the wires from the control unit to the impulse senders. The wiring harness does a lot of flexing each time the door is opened. I have found broken wires in that area.

 

Good suggestion. I will check that. Looking at the pin assignment the left and right door led are on 2 different pins. They should be on the left connector(15 pins connector), pin no. 14 and 15.

 

The wire continuity checked out ok.
Still no led light.
Any suggestion please?
Cheers.

 

Do you think that this maybe is not a fault but is an optional function that only the dealer can program and turn it on?

 

maybe some one can help me out here; There are 2 wires for the Impulse Sender, one wire is connecting to the Alarm control unit, how about the another one? Is it suppose to be grounded?

Thks.