Wedge TR7: Wiper & blower won't work!

[stubear]

Hey Guys,

I've got a '77 TR7 (the one with the 4 fuse box). When I bought the car, everything worked. However, a week later, the blower motor and wipers both died. I checked the ground for both the motor & washer pump. Their grounds check out fine. It's almost like nothing has any juice. All the fuses seem to be fine. Any ideas?

Thanks!
Stuart Bear

 

[britishcarfreak]

You're going to have to be a tad more accurate when you say "It's almost like nothing has any juice".

Let's start with what exactly is working and go from there.

Sounds like a fuse. Maybe a previous owner fitted an inline fuse on those items.

Are the switches to those items functional (check that they open and close circuit by testing for 0/1 resistance on a multimeter.?

Have you tried hot wiring each device individually with a known hot lead from another supply just to check the devices are functional and properly grounded?

Get yourself a wiring diagram and see if the two items are in any way related to each other by fuse etc.

Hope I've been of some help.

 

[stubear]

Dear Glen,

Thanks so much for you help. I'm pretty new to auto electronics. I've found two inline fuse holders. One fuse looked about a hundred years old, so I replaced it.

I have a wiring diagram for the car. (There seems to be about 4 different diagrams for the whole TR7 series!)

I'll try your suggestion - hot wire the blower motor directly. That will give me some idea if it is indeed functioning.

Thanks!

Stuart

 

[srmorse]

Hi Stuart--

The same thing happened with me (not on the wipers, but just about everything else) when I first got my TR7, and just about every time it was a bad switch (or gauge). Cleaning the contacts sometimes helped, but not always.

--Saul

 

[stubear]

Hooray! I found the problem!! I also solved about half-dozen electrical gremlins at the same time.

I checked back at the fuse box-I couldn't believe that two accessories failed on their own. All the fuses looked good. However, after checking them for continuity, the last one was faulty. The wire wasn't burnt at all. I guess internally, it just wasn't connected. Kinda like a light bulb w/ a broken filament.

Thanks for all your kind help,
Stuart Bear
Montgomery, AL

 

[srmorse]

congrats on the find. Those old fuses tend to fracture at the base over time and you can't see the break...I know from experience...

 

[Eric]

Don't assume new fuses are good either. I had a fuse blow on my GT6. Popped in a brand new one - nothing! Checked continuity on the new fuse, and it was faulty. Stuck in another fuse and problem solved. Moral - when troubleshooting, assume nothing.