Wiper blowing fuse

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SirFoxx
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My tercel:: 1981 Toyota Tercel w/ 7age

Wiper blowing fuse

Post by SirFoxx »

Hello--

On my '85, I've got most of the issues sorted, except for one. When I got the car, the ash tray was full of 20A fuses. I found out those were only for the wiper circuit. Sometimes, when I put the fuse in, it'll last a day or so two before it blows again. Other times, when I touch the fuse to the contacts, I get a nice blue arc, indicating there is a dead short somewhere. I've already replaced the column switch, but that didn't fix it.

Where should I look? What areas could be trouble areas? Firewall?
1988 DLX 4wd Tercel Wagon w/ weber (RIP)
1985 4wd Tercel SR5 (RIP)
1986 Base 2dr Hatch (RIP / PARTS)
1986 DLX 4wd Tercel Wagon with ???
1985 DLX 2dr Tercel Hatch w/manual swap
1981 2dr Toyota Tercel w/7age (RIP)
1981 3dr hatch Toyota Tercel w/Turbo 4AGE
1981 3dr hatch Toyota Tercel SR-5
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Petros
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My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: Wiper blowing fuse

Post by Petros »

you might try running a jumper wire, direct from the fuse to the wiper connector, disconnecting the factory wire. that is to eliminate the possibility that the wire bundle somewhere is abraded and causing a short. the motor itself can short out too, jumping it will tell you if it bad wiring, or the motor.

finding damages wires internal to the wire bundle is a troublesome, but first make sure it is not the motor itself.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
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splatterdog
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Re: Wiper blowing fuse

Post by splatterdog »

Disconnect the wiper motor whenever possible to eliminate that. Keeps blowing and you need to find the rubbed thru wire. Scabbing in another wire can work in a pinch, but when a wire has problems the ones right next to it can too. Look for rub points on sharp dash metal.

I've been waiting for one of these problems to use my thermal imager on. You set up a self resetting circuit breaker to safely feed the circuit. This heats up the wire only up to the short to ground.
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Petros
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My tercel:: '84 Tercel4wd w/extensive mods
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Re: Wiper blowing fuse

Post by Petros »

I should have clarified, splatterdog is correct of course. the point of using a jumper wire is as a diagnostic tool. If you use the jumper for a few days and the fuse does not blow, than you know it is a problem with the wiring, and not the motor.

If you use the jumper and still get blown fuses, chances are it is within the motor, or wiring within the motor.

Intermittent problems are always a hassle, using the jumper wire is a way of narrowing down so you are not wasting time looking for a short in the wrong place.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
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marlinh
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My tercel:: 'Everett' Blue 87 4WD Wagon (Rocky 86, recently retired)
Location: Kootenays

Re: Wiper blowing fuse

Post by marlinh »

Have you checked to make sure the pivots for the wipers aren't seized? Just a thought, maybe that's why it's blowing fuses intermittently.
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SirFoxx
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My tercel:: 1981 Toyota Tercel w/ 7age

Re: Wiper blowing fuse

Post by SirFoxx »

The problem isnt that it's blowing them while the wipers are on. The fuses are blowing when I'm driving. I'll put a fuse in, itll work (sometimes), then a few days later, when I need to clean my windshield, the fuse is blown again. I doubt its a short in a motor since both wiper motors work fine.

My guess is there's a short in the harness. The reason I say this is because mice had made this tercel their home for awhile, and decided to move out sometime before I got the car. The car reeked of piss, the headliner is sagging and has what appears to be piss stains, and my rear speakers don't work. I'm not sure where the harness runs for the speakers and rear wiper, but if they run along the same channel, it'd make sense why the speakers don't work, and the wiper fuse is blowing (shorting to frame / body). Now, it is possible that the rear speakers are shot, but I would like to believe that both issues are related.
1988 DLX 4wd Tercel Wagon w/ weber (RIP)
1985 4wd Tercel SR5 (RIP)
1986 Base 2dr Hatch (RIP / PARTS)
1986 DLX 4wd Tercel Wagon with ???
1985 DLX 2dr Tercel Hatch w/manual swap
1981 2dr Toyota Tercel w/7age (RIP)
1981 3dr hatch Toyota Tercel w/Turbo 4AGE
1981 3dr hatch Toyota Tercel SR-5
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rer233
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My tercel:: Multiple

Re: Wiper blowing fuse

Post by rer233 »

If the fuse in question also controls the rear wiper, check where the wiring harness passes from the main car body to the rear hatch- I've seen wires break there, and it's possible the insulation could rub thru- causing your short. Also be aware that the "park" wire for the motor sees 12v whenever the ignition is switched on (regardless of whether the wiper is on or off.) My money's on that situation. Good Luck!
if it aint there, there's a good chance it won't break!
83 SR5 Silver/Blue (Snowmobile/work beater)-totaled but drivable
85 SR5 Blue
88 SR5 White (the 'good' one)-not anymore-totaled
87 fwd silver wagon a/t
87 4wd dx Cream (a/t- not anymore- now m/t)
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