[ceiling-tiles]

I am installing a new wiper motor in my 68 firebird with an E-Z wiring harness. There's 3 prongs on the motor and on the switch and whenever I hook the ground on the motor and the power to the switch I blow a fuse. Does any one know what I'm doing wrong? I've tried different switches and have used a ground on the switch and sometimes just having a ground on the switch blows a fuse. HELP!

[docvette]

[color=yellow][size=2]Doc Here

I'm not familiar with the EZ harness at all, A lot of the guy's out here are,

But just a thought, If the wiper unlock is not engaging while applying power, it will blow a fuse, Could this be what's happening?

Doc [/color][/size]

[ceiling-tiles]

I'm not sure what the wiper " unlock" is. What I am doing is having a power lead going to my switch and from there there's 2 wires that run to the wiper motor, I'm assuming on high and low speed, and blowing fuses when I turn the key. THe wiper motor has 2 terminals close together and 1 below it I'm assuming is the ground terminal. Seems real simple but I don't understand why I keep popping fuses.

[docvette]

[color=yellow][size=2]Doc Here

OK, sorry about that, should have explained.

Some stock wiper motors have a "Lock" function on the motor/gearbox.

This is to prevent the wipers from swinging around while your going down the road in the wind on a dry day.

Some are wired to the same terminal as power, some have an extra terminal to unlock it when power is applied to high/low.


If you apply power to the high/low side without unlocking the motor at the same time,The motor see's a rotor lock and blows the fuse.

Is yours One with an "Unlock" terminal?

I'll try to look at my body Schematics a little later and see if I have one for you and I'll post it if I have it.

Doc [/color][/size]

[docvette]

[color=yellow][size=2]Doc Here

OK here is a typical wiper motor schematic for 70's~80's General Mystery Vehicles with no whistles and / or Bells (like intermittent wiper, etc..)

It Looks like it requires 4 wires, unless they are using the Wiper Motor Case for ground (which would be unusual I would think.)

It also appears the power is constant, and the on/high/low is a switched ground. You may be testing it backwards.

Do you have another terminal on that motor somewhere?

Doc [/color][/size]

[ceiling-tiles]

Docvette, Thanks for the schematics. No there's not another terminal on the motor and there's a grounding strap on the motor that one of the 3 screws goes through to mount it to the body. Do you know if the hot lead actually goes to the motor and then to the switch? I figured that it would go to the switch and then to the motor. I tried to wire it up like the schematic shows and when I turn the key the motor was in high gear and working and when I switched it to low it blew a fuse. I appreciate you working with me on this. Thankyou, Sean

[docvette]

[color=yellow][size=2]Doc Here

No sweat on the help!...

Yeah I'd a figured that would be the way they would do it too..But If you look at the Diagram, The Hot wire Goes from the fuse straight to the motor, Then if you look at the switch, high/Low on both sides go to the switch, then the center-wiper side of the switch selects ground... Go figure??

So if that like yours, and you put power and ground across the two Hi/low's they WOULD short and blow the fuse...

Now this also might be in conflict with your after-market harness also..

hope it helps!

Doc [/color][/size]