When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
On a 1986 Camaro 2.8L V6, if a on and off toggle switch is installed to manually operate the fan, will this have any effect on the engine or the ECM? I installed one this morning and started the engine and it ran terrible. Shut down the engine, and disconnected the switch and now the engine runs as it should.
Did you wire the fan using the existing fan relay? The fan current draw is a factor as some fans draw 10 amps. If you wired the fan with new switch power going straight to the fan this might be your problem.
Mark, if I read you correctly, your saying I should use a separate 15 amp relay in junction with the toggle switch. I'd like to have manual control over that fan. Radiator fan switch activating at 230 degrees F seems a little strange to me .
Yes, and by the way, I did wire the switch directly to the fan. I guess running a separate relay would most likely allow a smooth engine run, I hope. I believe, I'll try a relay with the switch and see what happens. I can always reverse it back.
Mark, correct me if I am wrong. 30 to + post of Battery w/ in-line fuse 86 to toggle switch- other side of toggle switch to + post of battery w/ in-line fuse 85 to chassis ground and 87 to + side of fan motor and other wire @ fan to chassis ground Do I have this now wired correctly with a 15 amp relay? I just found a wring diagram that shows this set-up.
Do not see the diagram you are referring to. The fan relay coil is what you should be using. I do not have a diagram available but am thinking the coil has positive 12 volts at the coil and ground is applied to activate the relay and turn the fan on. The coil wires are the 2 smaller gauge wires and the larger gauge wires send power to run the fan.
The fan turns on a about 230 higher temperature than you would expect. Cars with AC turn it on when AC running. My friend is an original owner of an 89 Firebird and hardly ever heard her fan run until the radiator developed a leak and fan ran when she shut ignition off after a long drive.
You want to use the existing fan relay mounted on the firewall drivers side. It is part of a group of 3 relays that includes fuel pump relay.
Mark, believe me I am not playing stupid here, so let me see if I understand what you are telling me.
Run a wire from the Green/White wire Terminal F of the relay to the toggle switch for powering the switch and then run another wire from the other side of the toggle switch to the Black/red wire at the fan motor and leave the ground black wire @ the fan motor connected. Terminal F & Terminal A are the (2) small wires you are referring to-correct.
Bob, I hate to say this but I don't understand your directions.
Others are saying, I must go through the Radiator Fan Relay on the firewall. I know all a bout that relay. What I want to know is what wire color to feed the toggle switch from the relay and what color wire to feed the fan motor from that relay?
Thanks all I need to know. I am totally aware of where all those wires lead to from that relay, I ran a wire from the toggle to the battery and one to the motor. Fan worked fine. Started the engine and it started missing and back firing somewhat. so I disconnected the wires . Now it runs fine. I replaced the Radiator Fan Switch, What I don't like is the fan will not come on to around 225 degrees F. Too hot for me. I want to manually control that fan with a 2-post toggle switch. inside the passenger compartment. If you can supply the wiring info I am requesting, it would be very much appreciated. As far as hooking up a fan controller, I have no where to put a 3/8" NPT fitting. Derale performance says I cannot use adapters to make that application work because of the distance the probe will be from the coolant. They suggested , getting a 1/4" plug drilling it and tap it so the probe will fit straight into the block. I do not what to go that route. Simple toggle switch would be the answer to my problem as long as it does not interfere with e engine running improperly.
Run one wire from F terminal of the relay to one side of your new switch. Then connect the other side of your new switch to any ground like the metal on the firewall or any other place that easy. You could run this wire to battery ground if you like. The existing fan relay already has positive voltage on the D terminal via the tan white wire.
If you look at the drawing the ECM or computer and the cooling fan switch on the engine both supply ground to the relay terminal F. This is what Bob is telling you.
So to test with the key on connect a wire from the F terminal and the other end to any ground. Your fan should run.
Mark, that is exactly what I wanted to see.. One thing I am not is a electrical person. I dislike any electrical problem. Most of them always end up being a bad ground. Now maybe, I'll get a good nights sleep. Thanks again, for all your help. Greatly appreciated you taking the time to give me a positive conclusion to my question. By the way, I also have a 73 Nova show car. I do all my own work, but there are times like this, that I have to ask for help. I junked cars for over 25 yrs and had my own towing business for 12 yrs. But believe me, there is a lot I still don't know. Always something will cause me a problem., like this one. Thanks again.
Mark, one last question, on terminal F there are (2) Dark Green/White wires coming out of that terminal. One goes to the ECM and the other goes to the radiator Fan Switch. How do I know which wire to tap into?
Bob suggested using the one that connects to the head temperature switch as it probably the easiest place and will look the cleanest to connect your new wire going to your new manual switch.
I've already hooked it up by your description and it works after turning on ignition switch and then activating the on and off toggle switch. It started up and seems to idle okay. I'm not a bout to change it.
Mark & Bob, I did wire my toggle switch to the wire that feeds the fan switch from the relay, attached a ground wire to toggle and everything seems to work okay.
Mark, do you know of anywhere you can screw into the block or cooling system a 3/8" NPT fitting for a fan controller? Just curios, I have no idea where a port would be located. Derale Performance who makes the controller, told me I can not use any adapters, because the probe will give off false readings due to the probe not going into the block correctly.
08-12-2020, 04:53 PM
