cujo8

My original directions posted above were: I added a 3amp, 400PIV diode to the harness between white(85) and black(86) pigtail wires just behind the black socket to give the diode protection to this relay assembly (Diode stripe-end connector should be attach to the white #85. connector). To add the diode to the harness, I used a small jewellers flat blade screw driver to pop out the white and black female spade connectors from the black 5-pin relay connector. I bent the diode leeds so that it matched the spread distance of the white and black connectors when they were in the 5-pin connector. I cut the diode connector leeds down a little. so the diode would just stand ~ 3/16 off the back side of the 5-pin connector where the wires exit the connector. I then soldered the diode leads to the brass wire crimp ends of the white and black female spade connectors on the inside edge. The orientation of the diode is important, so follow the directions in the previous paragraph. Then insert the white and black female connectors back into the 5-pin connector exactly as they came out, so that the white wire connects to the #85 connector on the diode.

First off I want to thank the OP (Diesail) for the great write up on this topic. I basically followed his directions, but added diode protection to the relay harness just to be on the safe side. I now have switched 12V power for my on-board air compressor for my Air-Lift helper spring system. Thanks Diesail. cujo8

I ordered and received my 12VDC automotive 5-pin relay SPDT 30/40A (p/n-330-079) and relay harness (p/n-330-075) from Parts Express and this relay/harness doesn't have diode protection. Just to be safe, I added a 3amp, 400PIV diode to the harness between white(85) and black(86) pigtail wires just behind the black socket to give the diode protection to this relay assembly (Diode stripe-end connector should be attach to the white #85. connector). The diode can be purchased for less than $2 from Radio Shack.

I read the tech bulletin you linked to and it say's: "This bulletin documents the recommended practice of installing of a diode to Aftermarket Solenoids/Relays to Suppress Voltage Spikes (this is in the event Non-Automotive Grade relay or solenoid has been used). This diode installation eliminates potential excessive voltage spike." so it looks like you only need to add the diode if you use a non-automotive grade relay. Is the Bosch 12VDC 5-pin relay SPDT 30/40A p/n-330-079 listed in OP an automotive grade relay? I'm thinking that it is an automotive grade relay and the diode addition would not be needed in this case, correct? Thanks.

The VIN decoder does not work for Truck VIN's, any one know of one for trrucks?