60 series glow plug relay assessment (1 Viewer)

[Eurasiaoverland]

Below is a picture of two identical glow plug relays. On the left is a brand new (actually 30 year-old NOS) version and on the right is a relay from my BJ60. The car has well over half a million kms and is an indirect-injection diesel, so glow plugs will have been used for every cold start regardless of weather.

The old relay still works fine, I decided to replace it as I had this NOS relay in a bunch of parts I bought cheaply years ago and I noticed that the contact which connects to the bus bar wire was blackened from heat.

The solenoid windings on the old relay are slightly darker, a little glazed looking. The nylon insulator above it is visibly darkened with (I assume) heat.

For those with electrical experience, does the old relay look like it's on it's way out, or is this perfectly normal 'wear' on a well-used solenoid?

Old relay solenoid resistance: 13.8 ohm
New relay solenoid resistance 15.0 ohm

One other thing I notice: the solenoid rattles on its central post on the old relay, which the new one does not do.

Blackened connector terminal:

Thanks

EO

 

[duncanrm]

These relays are superb bits of kit.. such rugged and impressive engineering. Most importantly, they are maintainable! Unheard of for a modern relay in a vehicle. The blackening on that connector looks like the anodising breaking down a bit and the underlying connector corroding? I'd have no hesitating to keep on using it after cleaning it up a bit.

 

[Eurasiaoverland]

Absolutely agree on the quality - beautifully engineered.

On the blackened terminals I am not sure - are these brass terminals electroplated? I know there are tinned versions of some terminals (though I have not found tinned 305 (7.8 mm) terminals from Yazaki or Sumitomo) but I thought the golden versions were just plain brass?

I just opened my starter relay - same vintage as the old glow plug relay. It looks mint inside, just like the new glow plug relay and has a similar resistance across the solenoid terminals of 15.0 ohms.

Again a blackened terminal where the high current feed goes to the starter's magnetic punger solenoid.

Looking at the internals of the starter relay, and the resistance value, I'm beginning to think that the old glow plug relay is ready for retirement.

 

[duncanrm]

This one cleaned up nicely and is working fine.. (starter relay though I think.. especially with the flyback diode)