Hello to all !! I have been a member for quite some time, although i don't post often but need some help DESPERATELY !!! My wife owns a 05 Roadster that I purchased for her approx a year and a half ago. She has LOVED the car w/ the exception of the ongoing top problems. Now it is at the point that she almost hates it !! Here is where it all started: we purchased the car used (low mileage) and had ZERO problems until the rear glass separated. No biggie right ??!! Top recall ?? Yup, it applied. After that , the top leaked like CRAZY!! Mind you that I had a thousand dollars worth of seals installed because that was the only way that they said that they would warranty it against leaks during the top replacement. After FOUR repeat trips back because it would leak all over when it rained, they finally stopped the leak. After the third visit we started having issues w/ the top going up after it was put down. After the fourth repair that SEEMED to stop. UNTIL this weekend. Nice sunny Florida day right ? Top down, won't go back up. Each time the same issue, no matter which way you toggle the switch,the top goes down. Even if you use the tool to release the top and raise it partially , flip the switch and the top goes down. Any ideas? Could it be as simple as a switch issue or possibly a module issue ? Any and all help would be GREATLY appreciated !!!!

 

1) WHAT? Push one end, it goes up. Push the other, it goes down. If that is not the case, I'd ask you this: How old is the battery in the car? PLEASE DO NOT TELL ME IT CHECKS FINE, I did not ask that - how old is the battery in the car?

See, there is NO WAY what you are saying is happening can be possible .... unless someone has messed with the wiring in the console. That is, with one exception.

The top switch applies 12 volts to C1-pin 8 of the Top Control Module when you press "close". When you press "open" it applies 12 volts thru a dropping resistor. The TCM compares this dropped voltage with the voltage from the battery to determine in which position you have pressed the switch - up or down. (A stupid design, yes. But it saves one wire and a terminal on the module.) Now, IF battery voltage is low, the TCM may not be able to interpret what it is seeing properly.

IN FACT: A bad battery in these cars causes:
ESP alarms and glitches
No starting problems
Rough idle
odd instrument indications
the spoiler to deploy at odd times - or to refuse to retract
the Radio to act up
The engine cooling fan to run fast when not needed
.... other stuff I can't think of now

The idea that it could also confuse the TCM is not out of the question.

2) If you put the top up manually, WHY are you touching the switch? It sounds like you are TRYING to make it fail -what am I missing here?

 

How much resistance value is in pop syrup? Just a thought with our wonderful cup holder.. LOL.

 

Not a bad thought, either.

 

They said it leaked. The wiring loom is in the trunk. Infact there is a load of cables in the trunk.

 

Ohhhhhhhhhhhhhhhhhhhhhhh, damn Nick. Way to cut thru the crap!

 

I haven't studied the top and cylinders.. but isn't there a thread that started from the cylinder overhaul that mentioned travel limit switches?

 

Battery is less than a year old and ,YES, it tests good. You did understand correctly,no matter which way you push the top button , up or down, the top goes down. NO, I am NOT trying to damage the top. Trust me, I need no more top problems. What I was thinking was if ,maybe, the top was part of the way up,if it were some type of glitch, it might straighten up and continue to lift the top. OBVIOUSLY , it did not work. There have been no other issues w/ the car,no radio,window, alarm ,no anything just the ongoing top issue that has now manifested into a "not going up" issue.

 

Personally I have become a fan of "reset".. Disconnect the battery and let it sit for a few minutes..even turn the ignition switch over to fully discharge system.. reconnect and see if electronics play nice afterwards.

 

Other than MAYBE Miata's "reset" idea, I think Nick has the answer - water has leaked into the area where the TCM is and damaged it or corroded the connections.

But keep my comments in mind about a bad battery - if not for this problem, for future reference. Repeatedly, we have seen people pay hundreds of dollars in diagnostic fees only to find that a new battery fixes the car. And do not miss my point: The battery will "test" just fine, but will still fail in the car.

Also, I STILL don't think a bad limit switch explains this. I COULD be wrong, but to cause the top to go the 'wrong' way???? I'm not convinced either way.

 

How about a bad/wet/damaged control switch? Closure to same contact in either direction?

 

That is what Miata (or Nick) suggested. Not a bad idea, either.
The voltage difference between "up" and "down" is not that much, and, again, a HORRIBLE way to design the circuit.

NO wonder Mercedes are known, in some circles, for electrical problems.

 

So, where is the TCM located so I can check for corrosion ?

 

It is in the 'well' with the pump, driver's side fender behind the tail light assembly.

 

Update on the issue: FINALLY got around to replacing the top control switch. It worked great...three times... then, back to the same old crap !!!

 

So the top worked fine before the replacement and subsequent leaking? Sounds like you have quite the quandary there. I am not familiar with the power flow in the top operations, but it is downstream from the TCS. Now I am a little foggy on what exactly the Top Control switch is. Are you talking about the rocker switch that you push on the console, or the switch that actuates in the trunk well. Also You mentioned massive leaking form the top after it's replacement, What was the condition of the well? The deep area in the trunk under the styrofoam inserts. If it was full of water, you might have corrosion on all those connections.

I know thats not real helpful, but good exact informative posts and responses are what gets things fixed as opposed to frustrated rants. Keep your chin up, you have to be getting close to fixing it, is the company that installed the leaky top helping you pay for this?

 

The company that installed the top was the dealership. It was replaced as per the recall. The back window started separating. No, they are not helping at all. When it was leaking, it was leaking inside the passenger compartment. As far as the control switch that I was talking about,yes, I meant the rocker switch that makes the top go up and down in the console.It WILL make the windows go up and down but,when it is acting up, the top will not go up. As a matter up fact, it will stop in the middle of upward travel and start going back down until it locks in the down position. If you try to put the top back up again, nothing will happen.

 

Well since you have a new toggle switch now it's time to deal with your well. Alot of the mechanicals and electronics for the top are down there, and since you were taking water in the cab, I'd bet your trunk took on water as well. It could be corrosion or perhaps you shorted something out.

 

If you haven't looked into the well yet, time to do so. Once water gets in there it does not drain out on it's own. Look here for additional information on accessing the "well" area and getting it drained out . . .

https://www.crossfireforum.org/forum...tml#post491510