FIXED IT .

Poor earth connection on the main earth strap running from engine to chassis.

There was some paint on the thread where I screwed it to the body.... Just tapped it out & everything worked again..... Whew!

RUMPY BUMPY

O.k. the battery hook-up makes sense now, but still presents a problem as the battery's now behind the rear firewall.

Yes - Thermo wire is a power wire... Straight from ignition it appears (again - I didn't build the harness) running through a peizio-electric thermocouple relay.

When I say the lights dim.... It's not a major event, only just noticable.

Nah I meant running the existing thermo fan wire to a relay and the relay switches power to the fan directly from the battery.

No idea about the low impedance flasher, but I don't think it will solve your problem.

Which wire in the engine bay harness is connected to the fan? Is it straight from ignition?

Power is from the engine bay harness.

I'm 99% sure the engine bay & dash / ignition are wired correctly (Kev Rowley harness).

Direct to the battery........??
If I did that the thermo-fan wouuld keep running even when the ignition's turned off.
Either that or I'd have to rig up a seperate thermo-fan switch.
Not keen on that unless I have no other option.

Can anyone advise regarding a low impedence flasher unit?

Where is the thermo fans power coming from?

Sounds like youve got it hooked to the lighting fuse or something...

It should be run off a relay directly connected to the battery. It's a thirsty electric motor and needs a good solid connection to battery +

I finally thought I had all my electrical woes sorted.... Even have an interior light working(Thanks Datto7).

CA18DET grafted into a 1200 ute wiring harness......

BUT - When I took it for a drive last night with the lights on, I noticed the indicator was waaaay slow.
And when the thermo-fan kicked in, the indicators stopped working altogether : - (

So what's the solution?
I'm thinking it may be the switch in the flasher unit (it's a 2 pin cheapie) drawing a lot of current & when the lights & thermo draw, there's not enough to "flick the switch".

When I bought the flasher unit, the guy asked if I wanted a low impedance unit. It threw me at the time because it had 4 terminals & I only needed 2.
Is this what I want?
Are the other terminals to run (accessories)power to it from somewhere else?

I also noticed that the interior light / dash lights dim slightly when the thermo-fan kicks in.
Does this mean I've got a poor grounding somewhere, or is it just the old 1200 wiring struggling to cope with the CA's current draw?

Thanks in advance.

Coops