Fan Switch gremlins

[smithbks]

OK guys - I need help. I am driving myself crazy trying to figure out why my fan won't work switch operated. I wired it according to the JKleiner directions (which I know are sound) but I'm not getting anywhere. Here is what I did - I'm hoping someone has some suggestions: (Complete MK4 with RF harness, carb, mechanical fuel pump)

+installed the painless 180 degree switch in the manifold. I ran a wire from each terminal back to the switch. So the orange fan switch is wired to one tab on the Painless and then to the On/Off switch; the brown switch feed/brown gauge feed is wired to the other tab of the Painless and to the On/Off switch.

+the water temp gauge is wired to the temp sensor directly (came with gauges). But in looking at the manual for classic gauges it mentions grounding the black wire. I tried that but it didn't help.
++++should the temp sensor be grounded on the black wire?

+At first I didn't do anything with the green fan thermo switch. Then with advice I grounded it but still nothing.

My goal is to have the fan operate automatically and use the switch.

I am getting power to the switch and out as it lights the amber light. I am getting power to the relay in the panel. I am not getting anything out.
Help?

[DaleG]

How is the relay wired?
30=?
86=?
85=?
87=?

[smithbks]

The relay is wired as such:
85 - Orange wire (seems thicker than the fan switch wire but has no writing on it)
30 - Red wire (no writing but assuming this is a power feed)
86 - Green wire (no wiring but manual show the fan thermo switch going into the panel so assuming it is this)
87 - Blue Cooling Fan wire. This goes over to the cooling fan fuse
nothing on the 87a relay tab

Some observations:
Switch on 12v power observed: Orange and Blue wire, Red and Blue wire = but the fan doesn't come on?
switch off 12v power observed: Orange and Red wire, Red and Blue wire, Red and Green wire

Power not observed on the Painless switch tabs

[smithbks]

Does this somehow mean the Green Fan Thermo Switch wire needs to go to the Blue Cooling Fan wire at the fan? I had heard it needed to be grounded. (or back to the switch (orange wire?))

[Jeff Kleiner]

As I told you when we PM'd last week you have to ground the green wire. It makes the ground for the relay---without ground the relay will not work.

From the RF harness installation manual:



Electric Fan
 There are two ways to run the electric fan, use a dash switch to turn it on and off and keep an eye
on the water temperature gauge or, use a thermostatic switch to turn the fan on at 185° and off at
around 150°. The harness has been set-up for both ways.
Switch controlled
Ground the sending unit wire marked “Fan Thermo switch”.
Connect and attach the fan switch as instructed in the dash wiring section...


The Painless switch is a non-grounding ON/OFF switch whereas the one included with the kit is a grounding switch---that's what trips people up. When using the Painless switch you wire it as if you were ONLY using the dash toggle. The Painless switch is then piggybacked in parallel.

Soooo, let's back up, forget all about the thermo switch and first make it work with the dash toggle:
---Ground the green "fan thermo switch" wire that is in the sending units/electric choke branch of the harness.
---Go to the dash harness and find the brown "fan switch feed" and orange "cooling fan" wires.
---Connect the brown to one terminal of the toggle and the orange to the other terminal.
---You have two essential harness grounds---both are black wires with ring terminals labeled "ground"; one comes from the brown plug on the front harness and the other is in the main harness. Assure that both are landed to clean secure chassis grounding points.
---Plug in the cooling fan, turn on the key and it should work!

To incorporate the Painless switch take a pigtail from the brown wire at the toggle and run it to one terminal of the thermostatic switch. Take another pigtail from the orange wire at the toggle and run it to the other terminal of the Painless switch.

If you want to have an indicator light run yet another pigtail from the orange wire on the toggle to one terminal of the lamp. Take a wire from the other lamp terminal to ground.

All of this will allow you to turn the fan on manually or allow the Painless switch to do so when the coolant temperature reaches it's activation point. In either case the light will come on when the fan relay is energized.

Hope that helps!

Jeff

[smithbks]

Thanks guys. I'm travelling this week and will do this Saturday and report back.

Jeff - I figure lots of people ask you questions and didn't want to keep bugging you. I appreciate you helping.

I will say that what has me puzzled is that I did just what you describe above and did not get it to work. I'll back up and isolate just the switch first and check for that ground to be sure. There has to be operator error (me) at work here !!

[Jeff Kleiner]

No problem Brian, I'm always willing to help if I can. If those harness grounds are not connected the fan can't run. During your troubleshooting have you verified that the fan itself will operate with jumper wires directly from the battery? Give me a call if you need to.

Jeff
812 327zero393

[smithbks]

Just to close the loop on this in case it ever helps someone else...

I went back to the basics and read about relays a little more so I would understand everything. In the end, as Jeff predicted, it came down to a ground. What I did was visually track and confirm all of my wires and follow Jeff's post. Then, I took the multimeter and tested the circuits. With the switch off - everything as it should be. With the switch on the amber light was coming on and I tested the switch power = all good. But, at the relay the the orange wire and green wire should have read 12V with a test lead on each. Nope. I grabbed an alligator clip and put one end on a frame ground and touched the other to the green wire = success - the fan came on. So I now knew the problem was the wire. I meticulously followed it back and found a very, very stupid mistake. Where I had pulled it out of the harness wrap in the dash and cut it to ground it, I ground the wrong end (the one that dead ended in the sender harness in the engine connected to nothing) instead of the panel end.

Another lesson learned and stupidity overcome, but through this process I understand relays much better than before so in some ways it was worth it.

I will now be go-karting this Friday!! woo-Hoo :cool:

[Jeff Kleiner]

Great news Brian! Sorry I missed your call---I was knee deep in painting one most of the weekend. I called back yesterday evening and left a voicemail but by then I had received your text letting me know that you worked it out.

Let us know how the go-karting goes!

Jeff