Baja Joe

First, thanks for all that post here. It has answered my questions from MAF to MAF Relays to Cooling, to Air Dam, to Heater Core Replacement.... The list goes on. I picked up at 1989 IROC Z28 red convert with 68k miles. MINT. But from sitting for a long time it needed some TLC. Bought it for my wife and she is having fun reliving the Big Hair 80s!!

Ok, So I am fine tuning this whole cooling issue. The PN for the fan relays is great and I plan to install a 180 TS and lower the fan relay ON temps. Plus put in a manual override (read "I am in traffic on a hot summer day and the temp is going up!") to just run the fans in case of emergency

My question is this. Both the #1 and #2 fans run off of relays that go to ground. Why can I not just take the #1 fan, and jumper the #2 fan ground wire to this. This way when the #1 fan temp switch goes to ground then both fans go on? It seems that if the car is going north of say 220 that I want a lot of cooling? FWIT the system is working now but I have never seen the #2 fan go on since it still has the stock 246F switch.

Most relays pull very little amps so I cannot see why running two relays on one wire would be bad?

You thoughts?

92RS_Ttop

iTrader: (3)

The issue is not the current draw of the relays, but the current draw of the fans. Each fan takes a lot of amps to start up when the relay closes, which is why the relays are there in the first place. Having both fans start at the same time ill put a large strain on the factory alternator to provide enough current on top of what everything else is already drawing. Once the fans are spinning, their current draw drops off considerably.

Baja Joe

Very interesting on the combined amp draw. I can look at the wiring cct but this initial surge would be picked up by the battery?

I may measure this and report back. Thanks for the insight on this.

92RS_Ttop

iTrader: (3)

The battery is only there to provide the initial energy to start the engine, and to complete the DC circuit of the car's wiring by providing a ground path. Once the engine is running, everything is powered by the alternator. It also charges the battery back up to full of course. If your not running a lot of other electronics or a high-wattage sound system, you might be alright but I wouldn't bet on it. The second fan is only used by the cooling system if the engine gets really hot. It also turns on when the AC is running to help cool the refrigerant.