Intermittent PATS (passive anti theft) problem

[Captain Morgan]

A relay has 2 connections that pwr it and 2 or more connections for the circuits they switch. In order to test it more than putting a voltmeter across it you would have to keep it powered and see if it falls out and fails to stay powered. How are you going to do this in a real world scenario with vibration and heat etc? For how long?

Old relays have tarnished, oxidized or corroded lugs and the electrical connection to the pwr or the circuit it switched be intermittent. (only needs to be a fraction of a second in some cases to freak out the brains)

Replacing the relays assures that you can put in a relay that has a clean burnished surface and hasn't been subjected to years of heat and use, but if the socket it plugs in to is also tarnished and oxidized it may still not have a sound and reliable electrical and mechanical connection. If it were me, I would use a tiny flat file to score the female socket where I plug the relay in to.

Relays are cheap whether they are old school or completely electronic and you can swap these out yourself.

I found THIS as a PCM-relay-getting-voltage-diagnostic test on another forum.

For less then the cost of the repairs you are mentioning, you could swap ALL of the relays and fuses.

 

[ELVATO]

For what it's worth, the solution to the problem in the link you posted from the ford-truck site is to replace the fuse box. The early 03's had an issue with the fuse box (CJB) circuitry that would fry PCM relays. There's a thread about it on the site.

Heh, at least our PCM relays are a whole lot cheaper since they're the generic skinny ones.