• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

TR2/3/3A Wiper stuck

Share this page

Jim_Stevens

Jim_Stevens

Jedi Warrior
Gold
Country flag
Offline
I started the TR up and just for fun, turned on the wipers. The wiper blades went up halfway and quit. I also noted the ammeter was abnormally high. This was after the initial battery charge settled down. I opened up the bonnet and the motor had voltage, however, the motor was hot to the touch. I believe it was because it was still energized and seeking to return to the rest position. I’ve disconnected the battery. Fuses are good.

I suspect mechanical binding. In the morning, I’ll disconnect the shaft and try running the motor. Any other ideas? Jim
 
Thanks for this. I do hope it’s a brush or something electrical. The thought of getting to the wiper mechanism in the dash is daunting.
 
Any time you stall a motor, it will get hot. A hot motor does not mean that the problem is in the motor; it could be in the wiper mechanism. It should be easy to test the mechanism by trying to move it by hand with the motor removed. If it's in the motor, it is most likely to be something jamming and preventing the armature from turning. It could be as simple as old, stiff grease in the gears.
 
Hi Jim you should be able to disconnect the mechanical end of wipers by removing the long flat cover with I like 4 screws and pulling out a horse shoe clamp and linkage arm connecting the mechanical from the electrical motor. The horse shoe clip is small and easy to loose and could be underneath the connecting arm. After that the wiper mechanical side should be free to move by hand.

My guess is the motor brushes are worn out or the armature is starting short out and that the mechanical part with worm gears is fine. I have one tore down if you need pictures.

Steve
 
Good news, so far. It wasn’t mechanical binding of the wiper mechanism within the dash. I disassembled the motor, and have 8-ohms across the stator, which looks about right. The armature resistances are consistent, at 0.5 ohms. One of the brushes is worn more than the other, but not an issue. Hmmmmmm.
 
I’m going to have to reassemble and bench test it. Somewhere in this blog, there should be a diagram on how to hook up the 12-v for the bench test.
 
Just to wrap up: Not sure it was the cause, but I found the thrust washer for the crank pin folded in half and wedged near the worm gear. My guess is the previous guy who rebuilt the box (yours truly) didn’t realize the thrust washer was not installed or had slipped off. I also didn’t like the brown grease I had used, so I cleaned it out and replaced it with red hi-pressure sticky grease. Bench test sat. Thanks to the Steves and Tom.
 
Back
Top