Adding Heated Washer Fluid
This was one of my more challenging modifications simply due to the number of considerations in making everything “OEM”.
The module comes with a bracket and has two wiring connectors attached (one has been removed but is shown in the secnod picture). The smaller of the two is for control signals while the larger is for main power. This unit requires a 60A fused circuit (yes, the headlights dim slightly when it’* on). Depending on the generator output, this may not be a suitable modification for some stock vehicles. I constructed two wiring harnesses. The first connects to the smaller connector and all but one conductor is fed through the firewall near the passenger foot well. The remaining conductor is for ‘ACCY’ power and is routed into the fuse block in the engine compartment. Special connectors are needed as these are “sealed” for moisture reasons. The main power connector was removed entirely. The negative and positive wires bolt onto studs located on the bottom of the module. I considered purchasing a mating pigtail, but when I found the cost to be anywhere from $305.00-$500.00 (depending on source) I elected not to.
This photo shows the module (I’ve already removed the high current connector).
These are the high current and control connectors.
Now with the new wiring attached.
This module is activated by pushing a momentary contact, normally open switch. The module begins a specific cycle of heating fluid then spraying while turning on the windshield wipers. Because the module grounds an input on a BCM (in the Cadillac) there were additional modifications required to make this work. The wiper arm in a Bonneville provides a +12 VDC signal to the wiper/washer module when you push the wash button. Since the heater module provides a ground, the two aren’t compatible. My solution was to use two relays in the rear fuse block. Since the 2004 Bonneville doesn’t have the fuel door lock option (even though the relays exist), I was able to use this portion of the fuse block. The fuel door lock uses two SPDT relays, one to lock and one to release. I replaced these with SPST (very important to maintain correct function of the wiper/washer system). I use the heater module to ground the coils of these two relays. The contacts from one will supply +12 VDC to the wiper control line and the contacts from the other supply +12 VDC to the washer fluid pump.
In order to maintain a ‘stock’ appearance, it was necessary to modify the fuse block to accommodate a 60A circuit. 1993 SLE has done some of this work in the past and shared valuable information from his experiences. It was necessary to disassemble, add parts and reassemble the fuse block to complete this portion.
The underhood fuse block removed.
Fuses and relays removed.
View with halves disassembled.
Here is a picture with the new 60A circuit (black connector).
The addition of an 'ACCY' power feed.
This module must be mounted as close to vertical as possible (although a slight angle is okay). There is an air chamber at the top of the heating section in case the washer fluid freezes and expands. This will help to prevent a failure by cracking the casing open. Because of this, there are a limited number of places to attach this. Additionally, the heated washer fluid module needs to be mounted as close to the spray outlets as possible to avoid heat loss along lengthy washer hose. Fortunately I was able to mount this close to the firewall on the passenger side. Those who have a GXP will most appreciate the lack of under hood space available. I had to remove the stabilizer bar, coolant container and secondary air injection relay to facilitate addition of a wiring harness. It is possible with some adjustment in bends to use the bracket that comes with the module.
Mounted module (fluid lines not connected yet).
Another huge hurdle was the switch to activate the system. This was a long, difficult and tedious search. Sure, any old momentary N.O. switch will work, but the trick is to keep the factory/OEM appearance. After finding no suitable solutions, I did some research into existing parts and decided to use a traction control switch. BillBoost37 offered some ideas based on some of his past projects.
Ultimately, I wanted to maintain a backlit switch with a custom symbol. The traction control switch is made using a multi-part process. It starts as a clear front button. It is painted white, then the final colour. It the GXP the buttons are black. The button is then laser etched to reveal the white paint underneath. The backlighting is softened by and visible through this layer. The white is also critical for daytime readability. I purchased a few traction control switches and sanded the finish off. An aerosol spray paint won’t come anywhere close to even enough layers so I purchased and airbrush. Paint was supplied by a local auto body supplier.
Currently, the switch caps are out being laser engraved so I don’t have a picture of the finished item but below are some photos of the initial process. I’ll post a photo once it has been engraved. Harofreak00 was critical in this phase because he took care of the artwork end of things for me.
This is the process for preparing the switch.
Button not yet laser etched.
I will be relocating my traction control switch to the centre console, just in front of the arm rest. This seems to be a suitable location and is out of the way to avoid accidental hits.