Ignition accessory feed

[Wayne S]

Hi All,

Where is the best place to take an ignition switch controlled feed for powering the relay for my electric cooling fan?

Is it fro the ignition switch itself? Somwhere in the loom? or something to do wth the fusebox perhaps?

Any directions or pictures would be brill. Ta [:D]

<b>2.0 Litre DHC Grinnall
Red 4.0 Litre V8 DHC Grinnall (with huuuuuge arches...!)</b>

[saabfast]

Why do ignition switch controlled? I ran mine directly from the battery via a relay controlled by the 'stat with a manual override. I did this as, as a mech building engineer, it is normal practice to remove residual heat in a system (it would be preferable to keep the water flowing but not easy in a car). It is surprising how often the fan runs on for a few minutes after switchoff . If it is good enough for my Saabs and most modern cars it is good enough for a TR7.

Alan
Saab 9000 Stg 1
Saab 9000 2.3 FPT Auto
'81 TR7 DHC

[Red]

I'd have to agree with Saabfast - it's always seemed a bit odd that they weren't connected that way to start with, no reason that cooling should stop dead when you shut the ignition off.
My Saab often sits 'panting' after I stop for a minute or two, so it does seem to warrant it. But then again, maybe that says more about my driving style than anything! [:o)]

Garry

1976 2.0 (soon to be 3.5!)FHC
http://reds-tr7.blogspot.com/

[PeterTR7V8]

Ditto.


Never say die. At least not while you're still breathing.

[Wayne S]

I would 100% agree and this is how I have run it up until now. However my Kenlowe thermostat has failed and i've replaced it with a switch in the top hose. However although I have stuck to kenlowes wiring to the letter (except for the ign controlled bit) it has managed to melt through all my wires on the control side of the relay circuit!!! [:(] so somehwere its putting too much load through. I was going to attempt the kenlowe advice of having a low tension circuit from the ign switch controlling the relays. It has 2 relays as its one of the 2 speed turbo boost jobs.

Does anyone have a link t a circuit diagram to saabfasts solution to help me get my head round it?

I hate electrics with a passion [V]

<b>2.0 Litre DHC Grinnall
Red 4.0 Litre V8 DHC Grinnall (with huuuuuge arches...!)</b>

[saabfast]

I 'did it my way', simple but it worked.
I took a fused supply to the fan from the battery via the relay power side. I then took a supply from the battery connection to the relay onto the control side of the relay with the opposite connection onto the stat and then a connection from the stat to earth so that when the stat makes it earths the control side of the relay and pulls in the fan.

I also took a connection from the relay fan connection to a warning light on the dash then to earth so I could see when the fan was running. To add the belt and braces I ran a connection from the relay connector to the stat to a switch on the dash, then to earth to give an override to the stat and manually operate the fan if necessary.

Sorry, difficult to describe in words and not sure how to load a scribble diagram. It used a few double spade connectors but most of the wiring, apart from the optional warning light and switch run to the dash, is kept around the area of the headlight where I mounted the stat using one of the cardboard blanking panel screws. Also used the existing light earth for the relay earthing.

Alan
Saab 9000 Stg 1
Saab 9000 2.3 FPT Auto
'81 TR7 DHC