Convert top intermittent

[sidneyandgary]

The top on my 95 Cobra wont lower. I can hear the relays clicking when I hit the rocker switch and I am getting power to the motor. I bypassed all of the switches and the motor will run both directions ok. Since the system has to have the grounding thru the park brake switch, I am thinking that maybe the General Electronic Module (GEM) may have something to do with this.
I am referring to a wiring scehmatic from a 2000 model as my Haynes has nothing concerning the convertible top for my 95.
I have thought about grounding the wire running to the park brake switch to eliminate the possibility of an intermittent problem there, but am afraid I might fry the mysterious GEM module. Anyone run into this intermittent top operation before?? Brushes in the motor going bad? Motor runs full tilt WHEN it runs.
BTW, after all the testing, the top is working fine again. I am going to have to drive around with a jumper wire and the back seat out so I can fix it when it goes inop again.

 

[94-302-vert]

Mine does that sometimes and I have to release and re-engage the parking brake unitl the dash light comes on, then it works flawlessly.

HTH...

 

[sidneyandgary]

I have cycling the hnad brake lever

The light comes on every time but still no change.
Does anyone have an idea of what the GEM does?

 

[donjohn]

i thought you were describing a problem with the fluid in the pump itself, not really a relay or anything... because you say the pump sounds like it's working, just the top isn't going anywhere right?

 

[sidneyandgary]

Vert Motor not running....

No the motor is not running, but I can hear the relay click whenever I hit the raise/lower button. I replaced the circuit breaker (located in the engine bay) and I thought that was it, but after a month of working, it quit again.
Today it is working fine!! I just hate these intermittent problems!!

 

[sidneyandgary]

Vert Motor not running....

No the motor is not running, but I can hear the relay click whenever I hit the raise/lower button. I replaced the circuit breaker (located in the engine bay) and I thought that was it, but after a month of working, it quit again.
Today it is working fine!! I just hate these intermittent problems!!

 

[mo_dingo]

No the motor is not running, but I can hear the relay click whenever I hit the raise/lower button. I replaced the circuit breaker (located in the engine bay) and I thought that was it, but after a month of working, it quit again.
Today it is working fine!! I just hate these intermittent problems!!

Just because the relay clicks doesn't mean it's working. You need to see if it's passing current to the proper wire.

There are 2 relays in the back; One is for UP, the other is for DOWN. They are mounted under the shelf, above the pump. The easy test is swap relays, and see if the top will go down, but not up. Then you have confirmed that DOWN relay is bad. R/I a new one & you will be cookin.

But the proper way is to have someone press the up button while you probe the wires on the relay with a test light and see if it's passing current through when the button is depressed. I don't know which pin on the relay is the one that activates the pump, but it will have 12V+ only when the switch is depressed.
Scott

 

[HISSIN50]

Wise advice from Scott. BTW, I think GEM is for later model (OBD-II) cars.

Dont forget to check your power feed to the relays (common terminal). On a fox, there is a fusible link off the battery for this. The CB you checked is only on the control side of the relay - the fusible link is for the power side. SN's might have a fuse instead, but the power side should still be fused somehow.
The relay coils are working probably since you hear a click (coil closing), but with no power on the common terminal, it cant pass power to the N.O terminal.

Good luck.

 

[mo_dingo]

Wise advice from Scott. BTW, I think GEM is for later model (OBD-II) cars.

Dont forget to check your power feed to the relays (common terminal). On a fox, there is a fusible link off the battery for this. The CB you checked is only on the control side of the relay - the fusible link is for the power side. SN's might have a fuse instead, but the power side should still be fused somehow.
The relay coils are working probably since you hear a click (coil closing), but with no power on the common terminal, it cant pass power to the N.O terminal.

Good luck.

Right, if you don't have your 12V constant, there is nothing to pass through. I wonder if the 12V constant is shared to both relays. I really wish I had a really good wiring diagram for my car. It would help solve a lot of electrical problems.
Scott

 

[HISSIN50]

Scott, the 12 volts is shared on a fox - I dont think they change much for vert plumbing and wiring over the years. It would be dumb to have two separate power supplies since only one relay works at a time. ya know (which means I am probably wrong. LOL).

 

[mo_dingo]

Scott, the 12 volts is shared on a fox - I dont think they change much for vert plumbing and wiring over the years. It would be dumb to have two separate power supplies since only one relay works at a time. ya know (which means I am probably wrong. LOL).

yeah, the infamous "redheaded stepchild" name will probably hold to be true, and they would send a seperate 12V wire to each relay...But yeah, why not run it in parallel, since the top only goes up or down, neither at the same time, it won't draw any more current so no need to up the size of the wire nor the amp rating of the fuse.
Scott