jwbeck17

So far flipping the sender connector didn't help. i switched the light pins and verified that the light pins are still good as the y both work in the passenger side. I am trying to test out the sender by checking fo continuity on the connector pins while outside the car, but I am not getting a reading there. Also tried hooking the pins up to a 9 volt and seeing if i can the pin to light while outside of the car, but no luck.

Unfortunately I am no electrical expert, so I welcome suggestions on how to test the sender and also test the connection to the sensor.

NoVector

I wish I could help you with the solution, but I can only offer that mine was flakey too when connecting the new module. In my case, the passenger side didn't blink so I took the module off the driver's side door and tried it on the passenger side. It worked. So I was fairly confident it was a bad module and I bought a replacement. But when I installed the new module on the passenger side, it still didn't work... hmmm. So before I returned it, I thought what the hell, let's try the new module on the driver's side door - and voila, it worked. So new part worked on the driver's side but not the passenger side. I then took the known working one that used to be on the driver's door and put it on the passenger's door and double voila, both worked! I don't know if I had the connection backwards like Bertrand suggested; although I don't think I did. Nevertheless, if you have both door panels off, you may want to try swapping your new module on the other door just to make sure it's working. And vice-versa, take the known good module and trying it on the door that doesn't work.

FWIW, for the price AND while the panels were off, I regret not just buying 2 modules and being done with it - thinking that both would fail about the same time.

jwbeck17

So I guess my best shot here then is to remove the functioning passenger door module, test the new module in the passenger door and test the passenger door module in the drivers side door? I suspect that would help me eliminate the a faulty new module being the issue, as well as identify if the problem isn't farther down the connection. Or am I doing the multimeter method wrong?

Bertrand Daoust

Jason,

Have you found out what the problem is/was?

Here's a recent thread on the same subject:
https://rennlist.com/forums/928-foru...n-flasher.html

StratfordShark

Jason this is all fresh in my mind as I got mine working yesterday, and Bertrand has been good enough to post the thread I posted on this. The common failure mode seems to be the coil going open circuit, but it's not quite as simple as that...

For such a simple system, there are a number of variables which make getting it working properly a bit of a lottery if you're not too electronic-minded as you'll see in my thread. To summarise the various hurdles include:

The part number you bought, and the one originally installed in the car. They look almost identical, but the one ending 237 00 has no electronics in it to create the pulse, just a straight through connection to coil. The one ending 137 00 (PET lists the 137 00 for 89-, but my MY91 had 237 00 originally installed) looks the same but has electronics onboard, so that if you connect a 9V DC source to the connector and sit pin in coil, it will flash continuously.

The 137 00 part needs the connector jammed in the 'wrong' way to function

In my case, the coil was mounted the wrong way round, so the PIN would only flash if the coil was oriented opposite to the way it sits in the door! I had to reverse those coil connections. If you're not getting a flash with 9V applied outside car or with connector reversed, then I suspect you have a new 137 00 part, and like mine the coil is mounted wrong. Turn it over so that the tab on the coil is pointing upwards (opposite to how it fits on door). Does the pin now flash if you drop it bottom down into coil? If you have the 137 00 electronic part, it requires positive power to the left hand pin as you're looking at it, with the slanted corners at top (NB this is opposite to how it's powered from the car with connector keyed correctly to the sender!)

Bertrand had a 237 00 part that needed connector reversing. There's no electronics, but in that case the coil was also the wrong way round. Since the inductive circuit powers a LED in the door pin, the direction of current flow in that coil will only work one way to pulse the LED

So a few variables to play with. I recommend you sit down at the table first with the new pulse sender and one of the door pins, and see what combination of connection and coil orientation results in a flash!

Feel free to post photos of what you have originally and the part you purchased, and I can try to guide you to a working flash. You sound like me in wanting to have everything on the car working as intended!

jwbeck17

Thanks for all the tips, guys! I haven't been able to work on the pin since my last post, as the weather got cold very quick and I don't have a garage to work in. I had planned to pull the passenger door one just to see if that would work, but haven't been able to do that either.

And I REALLY like the recommendation of working more with the part INSIDE, as it's just too cold to do anything on the car right now! It will be fun to test and post pics.

Jason

jwbeck17

Ok, so I tried to do the 9V testing as Sean suggested, but I couldn't get the sender to work. Since I was not sure if the issue was the senders or my testing, I decided to remove the known functioning one in the passenger door.

As today was approaching 50 degrees here and that I wanted to do some vinyl work on the door anyway, I was able to remove the door and remove the passenger sender and lock light.

When I took it in to the house and tested the passenger sender and door lock tip with my 9V setup, the test functioned correctly.

I then tested the same functioning passenger sender with the door lock tip from the drivers side, and it functioned correctly.

This ruled out the lock tip being an issue.

I then connected the drivers side original sender to the 9V and tested with the lock tip. It did not function. I switch the +/- connections on the sender and it still didn't function.

Lastly, I connected the new sensor from Roger the same way. Unfortunately it did not function either, even when I switched the +/- connections.

This confirms that I am not crazy, but have a bad driver's sensor and also a bad replacement one! I'm so relieved I have figured that out!

Next is to reach out to Roger!

StratfordShark

Renix

I have recently replaced both pulse senders on my brothers 89 with new 928 637 137 00 parts and could not get them to work.
I ended up having to plug the connector in correctly but mount the coil ring upside down as StratfordShark has suggested.

StratfordShark

Another variation on the pulse sender theme! Coil wrong way round but power connector the right way round. My 928 637 137 00 part had coil wrong way round and the power connector the wrong way.

They seem to have assembled these completely at random.

jwbeck17

So I was able to put in the new pulse sender. I bench tested it and it worked fine, then I put it into the drivers door buttoned it up and tested it out. Sadly it didnt work (passenger side did). I opened her up and flipped the connector, and it still didn't work. (I was able to confirm that the old sender was not functional, so it did need replacing.)

So now I need your help figuring out the next areas to check. Does it interconnect under the drivers seat at all? I know I have some loose solders down there...

Suggestions?

jwbeck17

jwbeck17

So I'm bringing this one back, as the drivers lock light had not been working for a while with charger or not so I gave up for a while.

I put on the trickle charger tonight and the drivers side lock light worked, albeit dim. I then unplugged the trickle charger to see if that made a difference, and I noticed that the lock light was still dimly functioning. The fact that it works tells me that the connections are right and that it is getting power, but i suspect not enough.

Any ideas on what could cause this?

Chris Lockhart

This is on my "to do list" which is 10 miles long right now, so thanks for bringing it back. Good luck with it.

jwbeck17

One thing I could think of in my case is a ground somewhere that I may have neglected to clean (however I feel like I have cleaned all of them). I also installed a new Sean Ratts signature knitted harness, so sit should be getting good power.

I can't tell from the wiring diagrams which grounds to look at for the door lock switch. Any of you have any ideas?