Car cutting out when thermo kicks in

[STR8 2.8]

on that token, a lot of cars shake to the shithouse when the thermo comes on, if its of decent size, they draw too much current and the engine almost stalls. I had to up the idle RPM on my 302 because the fans suck so much power....

i agree, its surprising how much current they draw.
eg. a 16" davies craig sucks up to 19A!

[SL666]

A lot of factory thermo setups run like a two-stage setup, they run a resistor to slow the fan down on one circuit (looks like a big white ceramic block) and run full voltage to the other one, if you have the spare outputs you could think of doing this.

Alternatly, put a temp sender on the bottom tank/outlet hose and run the thermo completely separate of the ECU, otherwise you might end up having the thermo going while you are cruising along at 120..

I've got fans galore on my lux..

1x hyundai factory fan on the radiator (mounted on the front now though)
1x 9" DC fan on the trans cooler
2x 8" fans on the heat exchanger on the intercooler

the two fans on the exchanger run in either series or parallel to get the high-low thing happening, ive never really had to flick them to high yet.