1978 wiper problem

[Stephen B.]

can any one tell me where the power feed for the wipers can be found on a 1978 . there does not seem to be a space in the fuse box labled wipers and all fuses in the box are ok and I have no power at the motor if I supply power they work correctly Tnanks Steve

[Jack H.]

Re: 1978 wiper problem

It may be time to read your owner's manual & re-look at the fuse block. While I don't have a schematic diagram for a '78 Corvette, I have diagrams for '76 and '80. Both call out a 25A fuse in the main fuse block labeled 'wiper'....

[Chuck R.]

Re: 1978 wiper problem

Hi Steve,

Sometimes the labeling can be hard to read on the fuse block, but there should be a fuse for the wipers.

How do you know that the fuses are OK? visual? Tested? If you did a visual, don't always trust what appears to look Ok. If you ran a tester over all the fuses and you read current through all, then I would be looking at possibly wire connections at the switch OR the switch as a possible culprit.

Chuck

[Stephen I.]

Re: 1978 wiper problem

Just a thought....

Doeas the car have the delay function? That would mean that the fuse in the fuse block is replaced with a strange plastic "thingy".... The whole delay, wash wipe controler is under the centre console and if oit goes down it gives the impression of n a blown fuse. In this cae there is also a fuse "in line".

[Stephen B.]

Re: 1978 wiper problem

this car does have the delay function all the fuses at the box were tested with a test light. I have a lot of service books but not one for a 78 . 1980 is differnt and 76 is differnt. know all about the right stuff for the right job doing this for a friend and I just don't have a complete library sorry Steve

[Tom R.]

Re: 1978 wiper problem

Stephen:

I just ran out to check my 78 and the wiper fuse is prominently marked "WIPER" at the bottom right fuse. It's large (wire strand) so it's probably the 25A Jack mentioned.

Now having said that, my VIN is 9041 (Nov 77) and the intermittant wiper was withheld among early production models and not sure when it was equipped. Intermittants is a standard option but something wasn't ready. My window sticker shows a credit and I've confirmed all this. Later models equipped with intermittant will have a different switch marked as such. My point is that there may be some other electrical components I'm not aware of and if you're a later production model...it may have been equipped with this feature.

Let us know and I've got the wiring diagram for 78.

[Stephen B.]

Re: 1978 wiper problem

Tom the vin 1287l8s434132 and does have the pulse function .Like Steve irons said there is a plastic thingy in the spot for the wiper fuse and the print could not be seen .it is as you say in the lower right . so does this mean it has an inline fuse some where ???? or is the plastic thingy bad ??? thanks for the patience Steve wiring schematic would be great

[Tom R.]

Re: 1978 wiper problem

What I've concluded is that the intermittent was a feature included with ZX2 Convenence group so in early 78 this option did not include the intermittent feature. Later it was incorporated with ZX2 when ordered. So I take it you've got ZX2 which includes a timer function once the passengers depart from the vehicle and an under the spare tire carrier lamp.

The name for this intermittent feature is called "delayed pulse wiper/washer circuit" in contrast to "windshield wiper/washer circuit"

It also appears that two fuse box types were called for and its been awhile since I've done interior so basing it on these drawings but mine came with the traditional tube fuses while a different fuse box assemble must have been called out later. These use those plug in types fuses. In the latter the wiper fuse is located in the middle of the box and is a 25a fuse. However, it shows that when the intermittent feature was specified...an inline fuse was equipped and its 25 amps.

The AIM does not show an inline fuse which doesn't say a whole lot other than suggest that the inline fuse was part of the wiring harness assembly when ZX2 was called out and therefore not shown on the AIM sheet. So...it's got to be between the switch and the fuse box.

Locate the wires out of the switch and trace back to the fuse box. The diagram shows that from one end of the in-line fuse the wire is Brn Wht while the other end is brown. The brown end connects to a controller assembly which provides the "delay" feature...this would be some type of circuit board and could be no more than a flexible circuit with components perhaps in a plastic case but I'm just guessing. The controller wire harness will lead to the switch at the back of the dash on the left side.

This ought to keep you busy for awhile...let us know what you find out and good luck!

PS...pull out the plastic thingy and see if it's a fuse.

[Stephen B.]

Re: 1978 wiper problem

thanks for the wiper info your the best Steve

[Stephen I.]

[Stephen B.]

thanx every one!!!!!! *NM*

[Tom R.]

I'm curious...what's your build dates?

And that question is for both Stephens, build dates and VINs.

[Stephen I.]

Re: I'm curious...what's your build dates?

Hi Tom

In my case (or the car's anyway!) it's May 9th, 78.

Stephen

[Stephen B.]

Re: 1978 wiper problem

the vin is listed previously in this thread thanks again Steve