A shot in the dark maybe, but perhaps GaryDoug, Rob or some other electronics guru will know this...

I have a few dead RAP modules & am looking to swap the relays (pn VKP-15F42-Z04). These were disconned years ago & I can't find a datasheet anywhere--not even from TE Connectivity. I can get VKP-15F42 (not Z04) pretty easy & was wondering if I could substitute it. VKP-15F42 shows a max load of 40amp, but if you look @ the RAP schematic (on shbox.com) it shows relay2 has a potential load of 45amp; 15amp for the radio & a 30amp breaker for the window circuit. While this isn't continuous power, I can see a situation where the radio is on & you open/close a window. It would seem this might fry relay2. Relay 1 only has a 15amp load.

I don't know what the "Z04" signifies, but is it feasible to use VKP-15F42 instead? If I'm just gonna fry relay2, I'd be better off doing the bypass, but if I can swap those relays, that would be the ideal solution.

Any info is appreciated. Thanks.

 

@GaryDoug @shoebox

 

I would try the one without the Z04 suffix. That could be a special coil voltage like ones used in other GM modules that operate down to 9-10 vdc instead of 12 vdc. I would not worry about the 40 amp rating, that is for continuous use, not intermittent. Unlikely to be using the window motors full time.

Maybe something like this could be adapted: https://www.digikey.com/en/products/...C-9DE/18342708

 

Thanks Gary, think that's what I'm gonna try. I've got 3 or 4 to test with, so... I wasn't sure bout that amp rating, but sounds like it's nothing I need to worry about.

I looked for a cross reference & some AI bot says:
"Finding an exact substitute for the VKP 15F42 Z04 power relay can be challenging
due to its specific Z04 suffix. It indicates a modified contact configuration for high
current applications... If the Z04 modification is not crucial, a standard VKP 15F42
might suffice."

Dunno bout the "modified contact configuration"; they have an identical 7-pin footprint. Likewise the "high current" reference doesn't really fit.The traces are ample, so should be easy to swap 'em. Just gotta see if I have any silver/nickel solder around.

Will let you know how it turns out.

 

Maybe the configuration was for bifurcated contacts, invented to try to carry more current than specified or make it more reliable. In any event not too relevant in this case.

But I still think it is about the coil voltage. When the RAP is in function, the voltage is lower because the engine is not running. That means the relay voltage is lower and may not operate at the lower voltage especially through the wiring and contacts in series with the 12v battery. Look for failures if the battery voltage is at a minimum.