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1984 Rabbit Convertible Woes/Introduction

1685 Views 7 Replies 4 Participants Last post by  jettncab
Hey guys, I'll keep both the introduction and question short (kinda).

My names Steve, currently working on an 84 Rabbit Convertible that I've had sitting around for a good 7 years. It was my first car, bought with MY own money, title in MY name, all that jazz.. She was 'rigged' by some guys in New Jersey just good enough to sorta run. Bought the car for $500, after a good $1100 all together, here she sits. Overheating. Still.

Lets start with the previous owners crap. Claimed it was its 2nd motor, still a JH 1.8 CIS, this one HAS A/C. Einstein stuck a spark plug that was a bout 1/8 inch too big and stripped the spark plug hole to hell.

So we bought a new head. Head was fine, new headgasket. Good compression and the car ran fine for a good 9 months.

Took in out on a drive and it overheated to the point coolant was boiling out from under my closed res cap. Parked it up for a put a new waterpump in it, new hoses, flushed the rad did all that. Car ran fine after that. Made a bit of a mistake when wiring a new aftermarket radio and fired my dash wiring up pretty good. Then it sat, for years until recently I got my interest in the Ole Girl back.

I undid the burnt wires, and replaced them. Re-ran them so them weren't so bunched up and cleaned up some connections all the way around. Eclectically, in the dash wise, the car seems alright, except my tach and cluster seem to short(?) when I turn my highbeams on, my tach and gas gauge stop working completely when my highbeams are on and my coolant gauge, although the needle still reads my light seems to come on, as if I just turned the key. Also when the key is turned to ACC or 1 click my tach jumps to about 7000 RPM and dies back down, it seems to be running off my fuel pump for some reason, the tach needle fluxes with the buzz of the fuel system prepping. I think I have that pin pointed to: Blue Electric blue Space Fictional character Games

That. A really crap lead that seems to touch on to at least one more.
But Thats not my issue here.

Its my overheating.
I've replaced the waterpump some years ago and then the car sat, recently bought new hoses, new thermostat, and a new fan switch.

The switch I had, a 2 pin 95/85 switch ran into a 2 pin single speed fan. It worked for a while until things got weird. I got it reregistered and insured so took it out on some short road tests, then the long test, 45 mins to an hour out, at a red light my belt started squeaking like it was slipping and the car seemed to sort of died, I quickly restarted it with no problems and went home, didn't think too much of it until the next day, went out for cigarettes not 2 miles from home and my gauge spiked to the right and the temp light came on.

Quickly turned around and parked it.

--->What would cause that belt to squeal like a pig and the car to die like that?<---

The squeal could of been (what I think) an air bubble trapped somewhere that made its way to my water pump, making the pulley not move and the belt to squeak, the air pocket or pockets could also of been near my rad fan switch, making it not kick on, and thus overheating and such. After a few test runs the fan never kicked back on after I tried refilling the coolant.
I tested the switch in boiling water with a voltmeter and it did its thing at the right temperature so I know the switch is good, I tested the fan but I think my jumper wires are trash, when jumped the fan doesn't kick on, but when wired into the harness itself, HVAC on and set to A/C the fan turns on, so I'm assuming the fan is also good.

I added an aluminum thermostat housing, because strength, and I've got the correct thermo in there. Since then I've taken the radiator out and began flushing and testing wires.
Last time I had the car running to see if the fan would run I noticed my upper rad hose and waterpump being hot, while my lower hose was cold. Now, I just need to refill the system and try it out again.

Now a second question about wring for those who read this far..

Like I said before 2 pin 95/85 fan switch, 2 pin single speed fan. My theory is get myself a lower temp switch to combat the PA weather, but the only low temps I've found are 3 pin.

Text Diagram Line

I take my current set up, which pretty much besides looking like a 5 year old drew it, looks like this.

Text Diagram Line

and use the 3 pin fan switch with the 2 pin fan. That red and white wire, which I assume is a speed setting for the 2 speed fan has to go somewhere, or can it be deaded? Where would I have to splice that to if I did infact try and run a 3 pin fan switch? Again, ASSUMING it would just get hooked into the red/black +12 that comes out of my fuse block and into the fan? Correct me if I'm wrong.
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Tach is powered indirectly form the fuel pump relay, and they are part and parcel. Clean your grounds Frame to engine, and engine to tranny or better replace them.

The over heating is probably but not limited to.
Air Bubble at the t-stat, if you drill a 1/8 inch or 1/16 inch hole in the lip of the t-stat you don't have those issues.
They make a 180 t-stat.
To fill without drilling a hole, you have to loose the upper hose from the Radiator and the outlet on the head. You will fill it from the head side first until it bac fills the hose a wee bit, then take the hose and reverse it and fill the radiator.... once you have fluid dribbling out, then reconnect the hose and fill the expansion jug.

Squealing can be a bad bearing in the pump, and if you haven't replaced it yet you may want to order the housing and the water pump together.
You also need to loosen each bolt one at a time on the wp and coat the threads with never-sieze then replace and re-torque to 87 in/lbs.

Squealing can be a belt that is wet or oily that is as it is prone to road wash. is a good source for part number information.

If you have a/c then you would need a 2 speed fan.
The power is from the battery to the radiator switch, from the other side up to the fan, and a separate ground is required. Make sure the fan runs by jumpering it to the battery.

You may want to place a 20amp fuse in the circuit.

If you haven't flushed and back flushed your radiator and block you may want to to validate that it is clean as it has been sitting.

In the DIY's above there is a thread on it Backflushing your radiator, and then there is a how do I replace my water pump thread as well.

Also if you don't have an upper radiator card installed it can and will allow re-cycled engine compartment air over the radiator at a stop.
You can see no radiator card.

Radiator card.

This will dramatically reduce engine operating temps at a stop.
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2 speed fans are the three pronged, correct? Being an 84 Cabby I'm under the impression it only needs the two prong single speed, seeing as stock in the car right now I only have two wires going from my fan, to switch vand one of those coming off the fuse block.

I'm sorta asking is there a way to run a 3 prong switch into a 2 prong fan and if so how?

I lost my switch that I took out of my radiator and accidentally ordered a 3 prong low temp switch. Besides that the hole in the thermostat thing is going to be my next step, after I fill the car back up and run it with no thermostat to see if it could be a water pump issue. I can't remember if I have the small or slightly larger waterpump anymore so before I tare it down completely I might as well give her the ole test
Yes you can use the 3 pin in a 2 speed fan, just connect one side to power usually the left as you look at it from the back, then pick one of the 2 right ones to power the fan. the inner should be a lower temp You would splice a new wire from the switch to the fan with a insulated amp male connector.
Yours truly here forgot all the extra coolant in the waterpump from when I took the rad out like last week. I never took the thermostat housing off until today, and besides getting the surprise bath, I also found this. Again gonna yank the thermo out all together. My new 3 prong switch came today while I was out here impatiently wrenching so I'm gonna put the 2 back in seeing as it worked before, and tested out fine with a meter and hot water.

Fingers crossed


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You cant run with out the t-stat installed, it wont cool properly. Make sure that you have a steady flow at the small hose on the expasion tank, even at idle. That hose purges trapped air in the top of the radiator. The motor will over heat if there is no or little flow.
As a test or using flushing products it is best done with the t-stat off, and you only run the engine up to temp or for about 5-10 minutes, as the engine will heat up and the flushing product will work, the caveat is that most block and radiator flushes have to have a Drained cooling system running clear water or distilled.... I usually flush and back flush the engine afterwards and I usually use diluted baking soda /water mix to totally neutralize the flush as most are acidic.

As with most of these little critters you can flush and back flush the Heater core separately by removing the hoses off the block just make sure that you do it with a drained block and then when going back you start to replace every hose.....

That t-stat seems to be worse for the wear, and replacing it would be a good thing. If you decide to drill the 1/8 to 1/16 hole in the lip it will prevent the air bubble from hades... But if you decide to forgo the hole, then when refilling you need to fill the block, then the Radiator as that eliminates the air bubble usually and then burping the upper hose will help move any trapped air in to the expansion jug.

Be sure that you wrap the threads of the bolt with never-seize, and or Teflon tape, and only use a 6pt socket to the bolts they only take 87 in/lbs of torque to set them so don't honk on them and using a torque wrench saves you from stripping out the housing.
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Yes you can use the 3 pin in a 2 speed fan, just connect one side to power usually the left as you look at it from the back, then pick one of the 2 right ones to power the fan. the inner should be a lower temp You would splice a new wire from the switch to the fan with a insulated amp male connector.
Using a 3-pin switch for a 2-pin (one-speed) fan is plug-n-play (I speak from experience). (see page 3)

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