Convertible Top Pump Motor help

[oz]

Greetings,
I have been working on the interior of my ’91 convertible lately and had to put the top down and up a couple times (in freezing weather) without any issues. A few days ago when I tried to put the top down and it wouldn’t go.
The relay’s click in both directions but the pump won’t run. There is voltage to both up and down circuits. I took the motor out of the end of the pump housing and checked it out. There is electrical continuity in both circuits. I cleaned the ground, brushes and armature. I went to put the motor back in and there was some hydraulic fluid that had apparently leaked out of the pump. I don’t think it was there when I took the motor out (but I don’t think there is any sort of seal on the motor so I’m not sure if taking the motor out has anything to do with it). I reinstalled the pump and it still won’t work. I even tried tapping it (as described in a couple places on the web) – no luck.
I’d rather not replace the pump if I can avoid it but I’m not sure what’s wrong.
Has anyone had this problem and if so, what did you do to fix it?
THANKS!

 

[cobra10494]

Greetings,
I have been working on the interior of my ’91 convertible lately and had to put the top down and up a couple times (in freezing weather) without any issues. A few days ago when I tried to put the top down and it wouldn’t go.
The relay’s click in both directions but the pump won’t run. There is voltage to both up and down circuits. I took the motor out of the end of the pump housing and checked it out. There is electrical continuity in both circuits. I cleaned the ground, brushes and armature. I went to put the motor back in and there was some hydraulic fluid that had apparently leaked out of the pump. I don’t think it was there when I took the motor out (but I don’t think there is any sort of seal on the motor so I’m not sure if taking the motor out has anything to do with it). I reinstalled the pump and it still won’t work. I even tried tapping it (as described in a couple places on the web) – no luck.
I’d rather not replace the pump if I can avoid it but I’m not sure what’s wrong.
Has anyone had this problem and if so, what did you do to fix it?
THANKS!

Had the same issue this week on my 90 gt...both relays clicking and motor wouldnt turn..ordered a new motor and top wrked fine a few cycles then relays started clicking and motor wouldnt torn..rapped on motor and it started working and seems to be ok now...i tightned ground wire and checked all connections but strange the new motor did that.When the warm weather comes im goin to look deeper..i figured original pump motor 23 yrs old so at least its new.

 

[oz]

I wonder what is really going on? I read another post somewhere that said the system gets 'vapor locked' but that doesn't make any sense.
And I figured I could service the motor separate from the pump but fluid ended up leaking out...

 

[Onefine88]

The top motor is dead.

 

[oz]

well crap.

As far as motors go, is there an 'upgrade'? It looks like later Mustangs use the same pump with a different connector. Can I use one of those if I swap the connector?

Thanks!

 

[cobra10494]

Car sat overnight pulled out of the garage and cycled the top several times no issues.Go to hydro-e-electric they had a new pump out of box never used that i purchased from thier ebay auction for $139.00 shipped to door! Reg price $229.00.

 

[83GLXVert]

Read through the posts and was wondering if the problem you are experiencing could be in the automatic resetting circuit breaker for the main power to the pump itself. According the wiring diagrams I have seen the power supply for the pump itself is supplied directly from the battery through this circuit breaker which should be in the engine bay somewhere close to the battery or in the main fuse panel. Don't forget there are 2 fuses for the roof a fuse for the control switch & relay circuit and a circuit breaker/Fuse protecting the pump that is always hot (in my 83 its connected to main power terminal on the Starter Solenoid) As these things age and warm up during use they will trip prematurely.
I also wouldn't rule out the relays completely without further investigation either. Over time the contacts inside the relays get burned and heat damaged causing the pump to become intermittent. A relay that still clicks in and out only tells you that the coil is still good and nothing about the condition of the contacts inside the relay.
If you really want to know what a little bit of carbon on a contact, like in a relay, can screw up an electrical circuit, ask someone with an old fashioned points ignition system in their car.
These motors are started ans stopped in most cases with a very high current load so contact damage in the relays and circuit breakers is not only possible and highly likely over time.
Having said all that before tearing apart or replacing the pump I'd do a continuity check of the motor first checking the continuity of the motor to ground and between the 2 power leads with a multimeter. These motors are wired with 2 field/armature windings wired together series with a center tap to ground. If you have continuity between the 2 leads on the plug connection and between each lead and ground the motor is probably still good. Don't be fooled by a real low or 0 resistance reading as that doesn't mean the motor is shorted.