brickonwheels

iTrader: (6)

Over the past couple of months, i have been having cooling fan issues. It seems that i will pop a fuse either immidiately, or after some hard driving. For instance, at the track, i would blow a fuse every time down the strip, but if i put in a fresh one afterwards, the fans would work. What could cause this? I do have an msd 6al ignition, but beyond that, my electronics are stock.

extremez97

iTrader: (6)

im not positive but are the fans the only thing on that circuit. if they are maybe when the secondary fan comes on there is a problem with that fan motor. what temp is car at when the fuse seems to blow.

HBHRacing

the fans are relayed. They should not blow the fuse even if they draw too much amperage. It's probably something else thats on that circuit. Such as the air pump.

brickonwheels

iTrader: (6)

so the air pump is on that circuit? anything else?

HBHRacing

Probably not much. i don't have my book with me but the air pump fuse is extremely extremely common to blow, hence why there is a recall on the pump. Unhook the pump and stick a good fuse in. I'll bet you that it never blows again.

transam5.7lt1

iTrader: (18)

I'll second the chance of a burnt fan motor, passenger side......

transam5.7lt1

iTrader: (18)

Swap a relay to see if it fixes it...

brickonwheels

iTrader: (6)

already have swapped the relays, no fix

HBHRacing

It's not the fans. They are relayed and have nothing to do with the fuse. The fuse controls the relay coil and thats it. If there was a problem with teh fan it would burn up the fuse link, not the fuse.

brickonwheels

iTrader: (6)

so it is the pump then?

GOaT Cheese

The fans are absolutely fused! The relay is just a high amperage switch, but it is definately fused. Everything is fused. The relay is not a circuit protection device. The fan(s), depending on the application, is either one three speed fan, or a dual fan setup, one two speed, and one single speed fan. The single 3 speed fan is protected by a large 40 amp fuse.The dual fan uses the same 40 amp along with an auxilary 10 amp mini fuse for the third speed. And secondly the A.I.R. pump fuse, labelled "SAI" is its own circuit, and cannot cause a cooling fan issue.

HBHRacing

You are completely wrong. For several reason. I never said that the fans were not fused. I said that they are relayed, and that the fuses only protect teh coil side of the relay, not the power side. Got it? Secondly, whats this 40 amp and 10 amp mini fuse stuff? Have you looked at a diagram or are you just making this up?

Ok look. the System is run from one single 10 amp fuse. This controls the coil side of the relay, period. The fuse LINK controls the feed side of the relay. It's very very basic electronics, if the fans were going bad and drawing too much amperage, the fuse LINK would burn up, not the relay fuse. Period again.

I made one mistake, I didn't think about him having a 94. The AP fuse is shared on 96 but not 94. The rest still applies. It's more then likely something else on that circuit. I currently don't have my power distribution diagram with me for 95 and under, but the same thing that I said before will apply. What ever else is on that circuit is suspect. Find out what is, and start eliminating them. In the mean time, if I get to my diagram i'll let you know what all is on that system.

GOaT Cheese

I don't know how else I should have taken that comment? Which fuse is blowing? That would be a great help. And as far as me being completely wrong, hmmm, possibly, for '94, I don't have a schematic in front of me, I was going off memory. I can access GM dealerworld for anything '98 and newer, '94 was still a paper shop manual, I would have to go to the archives and pull it to argue further about fan controls for that year.

HBHRacing

94 can be either the early 2 relay or the later 3 relay system. Either way nothing as far as teh fuse is changed. It's all still simple electronics. The coil side of the relay is linked to a fuse on one side, and the PCM driver on the other. Never anywhere is the fans fuse actually directly linked to the fans themselves, that responsibility falls on the fusible link.