Cluster issues, Tach and MPG intermittent SI Batteries are GOOD?!?!

[Jdesign]

I have just removed the Cluster from my car thinking that the Si Board batteries were dying. I had symptoms of an intermittent Tach and the MPG gauge right below it. Oddly the tach doesn't cut out once it is working. It seams that if the car sits for a long period of time (between 2-3 days indoors of coarse) is when I have the problem. I noticed that once the tach works sometimes the MPG gauge will kick in shortly after(with in a few mins) and not exactly the same time as the tach, but they have both kicked on at the same time before. I have this problem for the first few minutes of starting the car all the way to two hours of driving. The Other issue that really has me puzzled is that the Oil check LEDs wont reset. I have reset them in the past without issues. Now they are stuck on amber and wont reset, another reason which made me believe the batteries were dead. I took pictures of my SI board and the batteries which I can post if needed but they look like they are in unbelievable perfect showroom shape.

I read on here about others that had similar problems but would also have issue with their temp gauge leading me to a simple solution of replacing the SI board batteries. Well I dissembled the Cluster and tested the batteries. Perfectly fine! 3.13 volts for one battery 3.12 for the other.

so now what?!?!I don't want to replace the board because it looks mint! Any help would greatly be appreciated!!!

[Jdesign]

Anyone? HELP!

[dnguyen1963]

Get the board under a magnifying glass and check for cracks in the solder.

[Jdesign]

Get the board under a magnifying glass and check for cracks in the solder.

I did. It looks spotless.

[Jdesign]

This is all I have for images right now but I will take more tonight. I sat and inspected the board for at least 10-15minutes

[Poorboyz]

Check the main boards solder where the tach mounts to. You might have to reflow the connections.

Sent from my Galaxy Nexus using Tapatalk 2

[Jdesign]

Check the main boards solder where the tach mounts to. You might have to reflow the connections.

Sent from my Galaxy Nexus using Tapatalk 2

will do!!! Thanks.

[Jdesign]

I think I found my problem!! Poorboyz youz duh man!!!

Look closely ay the solder connections. I missed this as I was inspecting the SI board looking for issues.

[Gregs///M]

I'm willing to bet that your SI board batteries are still dead or will die soon. They are close to 25 years old!

New batteries have about 3.3 volts. Also a voltage test is not conclusive, you must do a current load test which measures the battery capacity. This can only be done by removing the batteries from the board.

Good job on finding the damaged solder joint!

[dnguyen1963]

It looks like the OP has a replacement SI board already.

[Gregs///M]

naw, the batteries are marked may 1989. You can always tell if they are OEM with that amber colored glue between the batteries.

[jhaurimn]

Honestly, if you are having tach mpg issues, it's probably the si boards as Greg said. Solved my intermittent issues

[Jdesign]

I'm willing to bet that your SI board batteries are still dead or will die soon. They are close to 25 years old!

New batteries have about 3.3 volts. Also a voltage test is not conclusive, you must do a current load test which measures the battery capacity. This can only be done by removing the batteries from the board.

Good job on finding the damaged solder joint!

Thanks for the response. You are most likely right. I just tested for voltage not the load. I have fixed the solder joint an still have the problem :/

It looks like the OP has a replacement SI board already.

naw, the batteries are marked may 1989. You can always tell if they are OEM with that amber colored glue between the batteries.

Its most likely a stock board, just in really really good condition

Honestly, if you are having tach mpg issues, it's probably the si boards as Greg said. Solved my intermittent issues

I know, I just don't want to spend $200 on a new board. I Also want to find the actual problem rather than just replace it, if that makes sense?

[Gregs///M]

Thanks for the response. You are most likely right. I just tested for voltage not the load. I have fixed the solder joint an still have the problem :/





Its most likely a stock board, just in really really good condition



I know, I just don't want to spend $200 on a new board. I Also want to find the actual problem rather than just replace it, if that makes sense?

My boards are only $90 for r3v members. You can even send your old board back for a $15 credit.

[Jdesign]

My boards are only $90 for r3v members. You can even send your old board back for a $15 credit.

Sounds like a good deal... I will PM you!