Re: RPM-relay relay

["janvdwouw" <jvdwouw@xxxx>]

John Hervey wrote:
> Jan, I have the small relays that go in the door lock module, 
> They are almost an exact fit. 
[snip]
> The relay's in the RPM now coil resistance is 58.8 ohms
> in the circuit, the new relay's I have are reading 122 ohms
> out of the circuit. Most likley the won't work without changing
> the resistance to match. 

I'm allraedy further down the road: I bought a heavy (40A rated)
automotive relay that has a coil resistance of 84ohm.
I've allready taken out the original relay and have put in
wiring to connect the new relay to.
The new relay is either going to be mounted to the RPM-housing
or I'm going to put it next to the relay on the sheetmetal in the car.

The only thing the coil is connected with is pin 15 giving it 12V 
after ignition and the collector of a BC338. The BC338 pulls
the coil to ground (well allmost; you lose about 1,4V because 
of the transistor and a diode agains reversed polarity).

I will make some pictures of my modification and put them
on the web in the next couple of days.
Thanks,

Jan van de Wouw
Thinking Different... Using a Mac...
Living the Dream... Driving a DeLorean...

#05141 "Dagger" since Sept. 2000

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With the higher resistance of the coil the transistor has to 
carry less load (150mA opposed to 200mA), so apart from 
putting in (or on) the new relay nothing needs to be modified.