Parasitic drain and weird relay issue

[vs-lover]

I can never understand how anyone buys relays from an Auto store as here in Adelaide nearly every car that goes to scrap still has all of them installed, thus I have an absolute bucket full of them and will never ever find myself buying one.

 

[shadetreemechanic]

Yeah good point and they cost heaps too, I figured they're the first thing to go on a wrecker's car but I guess you proved otherwise...

 

[shadetreemechanic]

I reckon there is something wrong with the relay switching circuit rather than cheap quality relays. I recall the last time when the fuse melted I was swapping out relays to test and ended up with a second dead relay out of that blower socket (at the time I put it down to old age since they were all the original Bosch - Made in Germany ones).

I'm not game to stick any more of the good Bosch relays into that blower socket...what's my next option?

 

[wildfiremaint]

Hi, I would check the pin numbering
under the base of the relay compared to a genuine bosch relay from holden.

All 5 pin relays are not the same !
Cheers.

 

[shadetreemechanic]

Son of a....$%$#H
You're spot on both the Narva 5-pin and the new Bosch 4-pin have different pinouts. I feel like such an idiot now

Cheers guys for all your help.

 

[Immortality]

Oops....

 

[losh1971]

The dealership ones are only about 16 bucks. For a Commodore I used to go to a dealer. Although I now have a full set since I wrecked a wagon.

 

[losh1971]

One thing you will notice with a VR fan relay is they can burn out fairly quickly as they run a lot, especially if the AC get a frequent workout. The sockets the relay pushes into tend to get very hot and can arc out too.

 

[shadetreemechanic]

Yeah thanks for the tips mate, I'll see what the dealers round here want for new ones else I'll be raiding the local wreckers for sure.

In my case the relay connector isn't melted but fuse 9 was (partly because there was a 15A fuse in where it should have been 25A) but I have read other threads where it happened.

The fan gets a serious workout in my car that's for sure so I thought the motor could be offering up a higher resistance as it gets older as well. I mostly run it on high (speed 4) and that's the one going via the relay rather than the fan resistor.