I had my blower motor quit working and had a shop look at it. They said that the relay was bad, and that the blower motor needs to be replaced to because it was old and drawing more current and cased the relay to fail. I haven't seen this to be the case in the past, so could the blower motor be to blame. And should I replace it with the relay?
Thanks

It would be pretty easy to measure the draw of the fan motor with an ammeter. I would hazard a guess that you should be ok. Relays are cheap so if another one goes its no big loss. I would think that if the fan was drawing more power then it should, a fuse should be blowing before a relay burns out. The relays are rated at 30amps and I doubt your fan motor is drawing anywhere near that.

Thanks Max thats what I was looking for I was told it was drawing 25a IIRC. How would I duble check this I have a DMM that I can test current or do I need an ammeter?

Most DMM's can measure amperage. It should be as simple as putting the fan on high remove the relay, and put the positive and negative terminals of the DMM on terminals 87 and 30 of where the relay came from. Hopefully that makes sense.

25amps sounds high but I really have NO idea what a fan motor should draw. If I had to guess I would guess between 10-15 amps. If it really is 25 I would think you probably should change it. I doubt it would be that high. Let us know how you make out.

I'll bet the problem is with the blower motor resistor. When these go bad, though, you usually lose your lower blower speeds. They're just trying to hose you for a new motor, don't fall for it. Just have them replace the relay if that's what the problem really is.

Most DMM's are limited to 10 amps - make sure yours is capable of carring the expected current before attempting.....unless you were planing on purchasing a new DMM. Of course if it's your neighbors then it's ok.... You could place a shunt between one of the batteries and the battery cable then disconnect the other battery (all drawn current going through shunt). Turn key to acc -do not start - measure voltage drop across the shunt. Turn on fan and measure voltage drop across shunt. Difference is fan current.

you have to know the resistive value of the shunt or have test equipment like a battery tester? that will show current draw.....

current is equal to voltage across shunt devided by resistance of the shunt

Now a shunt is just a very accurate resistance that is capable of carrying a bit of current. The ones that I have seen look like a coil of wire something slightly less then 1/8" maybe 14 gauge (but they are made of a special wire). I have also seen them built into battery test equipment which may be the way to go, but I don't know if you can just purchase one seperatly

Well I replace the relay works fine I still haven't tracked down a meter that will work. I may have to go buy one this weekend. I took out the 20A fuse for the blower motor and put a 15A in there with no ill affects. The shop wanted $100 to replace the relay and $200 for the motor I was going to let them do the relay until I found out it was mounted on the firewall in my 97.

$100 to replace a relay? Relays are worth $5 at the most and take 30 seconds to change.

If it won't blow a 15 amp fuse you will be fine. Likewise for the motor, you can buy one for probably under $50 and change it yourself in a few minutes.

Damn stealers.

No, on my 97 the relay isn't just a relay it's an all in one deal it like $30 at AutoZone or $60 at the Stealer still it's plug and play. The motor is $30 at AutoZone, but looks to be a SOB to change remove the PCM, overflow tank, and ect.

That wasn't even a Stealer just some crooked a$$ shop I have been taking my Blazer to. That's the third one that's try to screw me over since I've moved out here. I miss using my Dads tools and shop to fix my cars.

They are not really reistor packs like they used to be, they are circuit boards now. They go bad all the time. I really dont think you need a new blower motor, otherwise it would blow the fuse on high setting if it was drawing to many amps