Hot relays and tune resistor - normal?
Hot relays and tune resistor - normal?
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taylormj4

Original Poster:

1,635 posts

291 months

Wednesday 8th April
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Hi Folks,
Is it normal for the Ign and Fuel pump relays and the tune resistor to get hot?

Just back from a 45min drive (including being in slow traffic for quite a while and it has been a hot day today) and noticed that these relays were hot enough to be a little uncomfortable to hold in your hand. The tune resistor is warm but at a lower temperature than the relays.

Is that normal?

I presume the relays are held in whilst the engine is running / IGN is on so have current running through the coils permanently, which will generate heat. They are of course now plastic-cased rather than the old metal-cased ones, which won't help.

Wouldn't have expected much current to be running through a tune resistor though.

Belle427

11,530 posts

258 months

Wednesday 8th April
quotequote all
Relays will be warm especially in hotter weather, tune resistor is an odd one though as I don`t think any current runs through it.

taylormj4

Original Poster:

1,635 posts

291 months

Monday 13th April
quotequote all
Update:
What I thought was the "tune resistor" was not actually the tune resistor. It is just a group of three black (presumably negative) wires looped in and out of a block. They were covered with a yellow sticker.

Turns out the connector terminals were tarnished and making bad contact, which is presumably where the heat was coming from and being conducted into these wire loops. It also appears to be a reason for the rough running I posted on my other thread:
https://www.pistonheads.com/gassing/topic.asp?h=0&...