any disadvantage to upgrading and rewiring the cooling fans?

[Dmc12]

I am getting ready to install a new radiator and upgraded low amp draw fan setup into my car and had a thought. I have seen posts about fan fail problems and other issues associated with the fans not coming on and causing overheats. What if when I installed the new fans a just made a completely new harness for them? I have done this for several other cars that I have built and never had a problem, why is the D any different? other than the fact that it would not be original, I dont see why it wouldnt be a much better system. Painless wiring sells a very nice kit that includes heavy gauge wiring, a relay and a thermostaticly triggered switch to turn the fans on at a pre set coolant temp. It would eliminate the facory wiring completely and just run both fans at the same time.

Does anybody see any issues with doing this?

this is also much cheaper than buying a fanzilla or similar product.

thanks for your input! :wave:

[Mike C.]

I'll be honest, Im running new fans as well. If you just upgrade the fan control unit and otterstat as well, you should have zero problems. I have had no issues with my cooling fans coming on at the designated time.

Plug and play + all wires in stock location = easier than custom wiring job

[dhaney]

I'll be honest, Im running new fans as well. If you just upgrade the fan control unit and otterstat as well, you should have zero problems. I have had no issues with my cooling fans coming on at the designated time.

Plug and play + all wires in stock location = easier than custom wiring job

This is really true and I would look hard at DMCNW fans. I've been running them for a couple of years, they are quiet compared to OEM and according to Toby's testing one fan pulls more are than both OEM fans.

Dan

[Farrar]

Regarding the original post: I was thinking of doing something similar as a redundant system, parallel to the stock configuration. Some folks down here have decided to retrofit their little British cars with electrically-controlled fans as opposed to the usual belt-driven job. Since they don't feel like drilling holes in their cooling system, the kit includes a special temp sensor which looks like a fancy ring terminal and attaches to one of the bolts in your engine block. You run your own 12v and ground wires, and the kit includes the relays and everything (except the fans, of course). When I upgrade to the low-draw fans I think I will go this route; it will save me hacking up the stock system which has a number of things wrong with it from the factory as you know. But as my stock fans still work, I haven't done this yet.

Just FYI.

Edit: I forgot to mention that you (and I, if I choose to run the wiring independently) would also need a dongle for the "a/c fan request" which turns on the cooling fans at the time the a/c compressor is engaged. AFAIK such a thing is available from both Painless and Ron Francis.

Farrar

[sdg3205]

It wouldn't be the worst thing even to have the fans also wired to a switch in the car with alternative wiring right to the battery.

You might never use it, but if for whatever reason the fans die through the OEM harness you can flip the switch and run them full time.

On the other hand if the fans die there might be problems with the fans themselves that would only make the problem worse. Who knows. I'm thinking out loud.

[Dmc12]

Regarding the original post: I was thinking of doing something similar as a redundant system, parallel to the stock configuration. Some folks down here have decided to retrofit their little British cars with electrically-controlled fans as opposed to the usual belt-driven job. Since they don't feel like drilling holes in their cooling system, the kit includes a special temp sensor which looks like a fancy ring terminal and attaches to one of the bolts in your engine block. You run your own 12v and ground wires, and the kit includes the relays and everything (except the fans, of course). When I upgrade to the low-draw fans I think I will go this route; it will save me hacking up the stock system which has a number of things wrong with it from the factory as you know. But as my stock fans still work, I haven't done this yet.

Just FYI.

Edit: I forgot to mention that you (and I, if I choose to run the wiring independently) would also need a dongle for the "a/c fan request" which turns on the cooling fans at the time the a/c compressor is engaged. AFAIK such a thing is available from both Painless and Ron Francis.

Farrar


thanks for the replies,

I have the high flow fans and rad from Special T that will be going in. I am leaning toward the seperate stand along wiring and controls just for cost and its simplicity. If both fans are wired to come on at a certian temp then there is pretty much nothing else to worry about. The stock system seems to have lot of things that could go wrong. I can leave all the stock wiring in place in case i wanted to return the car back to factory.

[Farrar]

Dmc12,

Which kit from Painless were you looking to install? I'd like to look at it and compare for my own use -- if you could post a link or model number, I'd appreciate it.

Thanks,
Farrar

[Dangermouse]

If you run a new harness, please make a drawing of it and keep it with your Manuals, to avoid the "dreaded PO" comments from future owners not knowing about this upgrade.

[Chris4099]

Replacing all the wiring seems a bit overkill to me. Most failures are due to the high current fans placing a lot of stress on underrated components. Replace the fans and components, and you should have a sold/reliable cooling system with the original wiring. By replacing the fans, you've already solved most of your issues. Making sure you have a suitable replacement for the blue fan fail module + original relay (if equipped), and you should be set! If you are still concerned about the otterstat, simply wire in a bypass switch or get a better designed otterstat like this:
http://www.delorean-parts.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=DPNW&Product_Code=K4002DP&Category_Code=9475

I myself have the low current fans, an otterstat bypass switch (which has yet to be needed) and the blue fan fail module+relay replaced with two modern relays (one for each fan). No issues and I should be set for life! If you are still concerned about fan failure, you can get Dave's solid state relay and fan failure modules which will alert you to a fan issue.

[JIMJAM]

I recently installed the Special rad and fans. Ignore any instructions on the wiring and look and verify both fans are turning in the same direction and actually blowing towards the rear of the car. One fan going in the wrong direction will not cut it. Ask me how I know this.......