One day my 1992 Camaro Z28 overheated. Opened hood to find the wire on the TPI Positive Battery Cable which joins with a fuse box COMPLETELY DESINEGRATED TO ASH! Took it to the shop and they replaced the Secondary fan as they claim it was drawing way too much current. They put in an order for the 1992 Camaro Positive Battery Cable ($100) and is on backorder for around 15 business days. Until then they bypassed it and put a regular pull out fuse. All fine and dandy... Or so I thought..

Drove the car for around 30 mins (stopping throughout) and the car began to BOIL.. LOUD! Look at my temp guage to find out COMPLETELY off the scale. Pulled over the popped the hood. The coolant was again bubbling like mad so much that the container was actually bouncing and the coolant hoses were vibrating. The rad cap and hoses were lightly spraying coolant... Sounded like it was going to explode!!

While waiting I called the mechanic and was told that the fuse likely blown and as a result it blocks the fan current and shuts them off. They said there is absolutely NOTHING that can be done until the cable arrives. And to basically keep an eye out and i'll be replacing the fuse left and right (25amp) driving VERY VERY short distances.

Waited an hour and the car cooled off to drive home. I am suspecting that when the SECONDARY fan turns on that it is shorting and blowing the fuse which causes a break in the circuit resulting in both fans turned off, resulting in OVERHEATING. This sound right?

Anyone else had this problem??? Anyone know where they can locate the cable "Positive Battery Cable 4SX33-1AC".

The mechanic said I could try 30amp and see if that allows it to go longer before burning out, hoping it's not too much that the wires fry.

HELP, BIG TIME!!

 

Unless you're running the A/C, only one fan is the primary in a dual fan setup and only when the car (motor really) reaches 238º will the 2nd fan kick one.

If the fans are blowing the fusible link, there is either a resistance problem (bushings in fan shot and they don't spin freely) or, there is a short somewhere.

The actual fan power is derived direct from the battery, attached by a fusible link (no standard fuse is inline with them).

The relay power is recieved from the 'fan' fuse (20a) underdash. The ECM controls the ground that switches the relay. The switching side of the relay requires minimal power. Doesn't hurt to check the fuse though.

An interesing bit of information to read about the current draw of the fans...

https://www.thirdgen.org/techbb2/sho...n+current+draw

I personally didn't like the idea of such a major current draw via a single 14ga wire so, I bought a car audio distribution block, 2- 20A slow-blo fuses (slow so they do no trip during initial kick on) and wired the fan relays in the same fashion one would a car audio amp.

The simplest test to finding if a fan is shot is simply... spin it... should spin freely w/o noise. If is doesn't... probably on it's way out.

Just my opinion though.. hopefully there's something in the above ramble that's useful..

 

You mean that the fuse under the dash might be blown itself and adding the bypass isn't working because the MAIN fuse under the dash is blown?

Also, can you check by turning each of the fan's manually without disconnecting anything? I mean by just turning the car off, reaching in and trying to turn the fan each at a time?

 

Yes you can turn the engine off and turn the fan blades by hand. If they make a lot of noise then they are on the way out as deadbird has mentioned. Does the primary fan work when you turn the A/C on? You can also test the primary fan with the engine off by jumpering pins "A" & "B" of the ALDL and turning the key to the "ON" position.

 

Anyway of testing the secondary fan?

Also, did he mean that the fuse under the dash is blown so the main culprit of the overheating is the blown fuse under the dash?

 

Not neccesarily, what he is saying is that the fan relay under the hood gets its power from the fan fuse under the dash. You can test both fans by turning the blades with you hand, if they turn freely without a lot of noise then they are usually okay and the bearings are good. You can also replace just the fan motor if it comes to that without replacing the whole assembly.

 

All the diagrams one could ask for and clairavoyant... you got it all Trckster

Yes, I did mean there is a fuse in the fuse block under the dash.
The fuse is ignition switched and supplies power to the coil side of the relay. If this is blown, regardless of weather the power side to the fans is good, the relays will not switch (because there is no power).

Here's a really crappy mspaint diagram to help confuse you even more lol (tip: Bud & Mspaint.. don't work well together...))

 

I checked the fuse under the dash (20amp) [Number 4] and it's not blown.

With the car off, I manually spun each fan. The secondary one was perfectly silent (should be since it's brand new). And Primary fan has a very SLIGHT high pitch squeek when you rotate it SLOWLY. THe slower you rotate, the loud the high pitch.. faster and it disappears.

 

To add to deadbirds mspaint & bud drawing, here is the schematic for the coolant fans in your car. This done after a few bouts with the "Captain" Cheers deadbird!!!!

 

page 2

 

The fan power wire (BLK/RED) and power from the battery to the relay (ORANGE) are 12 gauge wires.

0.8 = 18 gauge
1.0 = 16 gauge
2.0 = 14 gauge
3.0 = 12 gauge

 

I suppose you can add memory of wire gauge to the list of things that don't mix with Bud huh ? heh

 

To add to S10Wildsides list of wire sizes and to prevent any confusion as to sizes listed on the schematics. GM listed their schematics with metric wire sizes and provided a chart in the wiring section that would translate them to the American Wire (AWG) Guage standard. Here is the chart with the metric on the left going from smallest to largest.