[HO455]

Finally got all the pieces together to replace the compressor. First off the power lead had to be replaced as it was only 12 guage wire. The new compressor called for 8 guage wire for the 18 foot run from the battery. Biggest challenge to do this is replacing the wires that currently go to the control relays. The compressor is rated at 23 amps max load. The relays are rated for 30 amp loads but to the leads coming from the relay connectors are only 12 AWG. So to prevent voltage drop at the compressor it is best to upsize all the wiring. My compressor circuit starts at the factory power lug on the front fender then goes to a 20 amp circuit breaker ( auto resetting). Then to the power supply relay next to it. (1st photo, relay on the left.) The power supply relay controls the power to a second relay at the compressor. The power supply relay is operated by a signal that comes from the fuel pump controller (Revolution Electronics). This prevents the compressor from operating when the engine is shut off. (The PO had a fuse under the hood to do this. Pull the fuse every time you park for the night. ). Once the power supply relay is pulled in power is supplied to the compressor control relay. This relay is controlled by the pressure switch at the tank and starts and stops the compressor as needed (on 110 psi, off 125 psi).
Now connecting an 8AWG wire to the relay is not a plug and play operation. Here is how I did it. After removing the lug from the relay connector body, cut it about 1 1/8" from the lug and strip the insulation. Carefully open the first clamp on the lug. The one that secures the insulation to the lug. Set that aside and strip about 5/8" of insulation from the new wire you are replacing the old lead with. Then divide the strands into two sections. The first section will be smaller than the other as it will replace the insulation in the clamp you opened up. The other section gets trimmed back 3/16 of an inch and folded back for now. Place the first section in the clamp and close the clamp down on the strands. (See photo 2). Then solder those strands to the clamp. Let that cool completely. Then realign all the strands of the new wire and wrap the previously stripped strands, that are secured in the second clamp of the lug, around the new wire. (Photo 3). Then solder the two together (Photo 4). After it cools completely heat shrink and reinsert the lug back into the connector body. Be aware of the connector body's size and make adjustments to the size of your connection before soldering so it will click back into the body of the connector. If you are concerned about getting it to fit make a trial run to see if you will have a problem. In my project the total amp draw is not the issue but preventing voltage drop at the compressor causing it to run slow and hotter is the goal. I would not do this type of connection if the amp load was near the limit of any of the components.
Once all the lugs were upgraded I installed some chaffing protection on the wires where they ran between the fender and fender well from the relay area to the frame. (Photo 5)