Club 80-90 Forums

To get to the point of all this...
I was trying to find out for a member why his thick red wire to the element is getting hot, I thought that a grounded element would be the culprit but it seems that is not the case.
So, should we suspect the connection to the element offering more resistance and thus heating the wire?

More resistance means less current and less heat. Resistance at a locallised area will cause heating in that area but not along the full length. Maybe the lead has been replaced at some time with a thinner one but if not then even quite a thick lead is going to get warm with the resistances you mention.

I'll see if I can borrow a more accurate meter off a friend for Vanfest Kev

Google Ohm's law to get an idea of current and resistance and voltage calculations, before you fry your multimeter.
I = V /R
12 volt / 0.5 ohms = 24 amps
12 volts / 0.25 ohms = 48 amps

not many multimeters will read this high, even the digitals.
This open to comments!!
The heater probably does not connect until engine starts and/or key position is in Run position.

We're trying to accurately measure resistance, not current

I can tell you that the manifold heater gets effing hot ...FAST.
Also noted with the manifold heaters disconnected the cable that runs from No.1 relay is quite cool, when the heaters are engaged.
Reconnecting the the manifold heater starts to really heat up the cable from the relay with the connector getting quite warm, as was suggested a poor connection at the connector where the power splits to the carb heater creates a hot spot.

so assuming my ohms readings are correct...

Could this be a design flaw?
The manifold cable is really quite substantial but the cable to the relay seems a bit weedy..odd that!

I take it the cable to the relay is running from the threaded stud connector in the black box at rear of engine? If so just replace it for a thicker cable, only needs to be a few inches long to do the job.

interesting mark ..I may do that