car over heated when electric fan didnt go on

[luckythirteen13]

driving home from school today i noticed my temp gauge going way up. its about 90* today. when i got home the factory gauge reached 270 just as i pulled into the driveway. i babied it home never reving above 2500 usually had it below 2000. when i got home i turned the engine off and then turned the key forward to see if the electric fan would go on. it didnt but i heard this other funny sound. opened the hood to find the coolant in the resovoir bubbling it was so hot. it began to pour out the overflow and its all over my driveway. i think the relay died. does anyone have a link to a good relay. i have a temp probe. the bottom of the relay has black burns on it and some of the plastic melted near the positive wire. i was thinking i could get one at radio shack but have no idea what to look for or what type of ratings they have. im sure its at least 30amps

the car wasnt making any funny sounds and idle was really smooth so im hoping i got lucky
this is the fan im running http://cgi.ebay.com/ebaymotors/VOLV...06361QQrdZ1QQsspagenameZWD1V#ebayphotohosting
didnt get it from this guy but its the only place i could find a picture. im not using the fuse thing that is on the one in the pic

 

[HISSIN50]

I would use a Bosch 75 amp relay. If you read Monte Smith's article, he lists a part number (it is not one that I keep handy on the top of my head). Or do it right and run one of Brian's controllers.

Good luck.

 

[Michael Yount]

Use one of these -- www.dccontrol.com

And hope you didn't do damage. Why in the world didn't you pull off and let it cool down when you saw the temps creep up above 230F or so? Isn't that what the gauge is for?

 

[kn7671]

If this is a pre-94 model Mustang, then first be sure the wire gauge you ran for power wire to and from the relay is large enough to handle the current.

If too small of a wire gauge was used for the amperage being drawn from the fan, then the resistance will be too high, causing the wires to heat up and the relay to be hot. The heat from resistance most likely killed it, not the relay.

Be sure to use a minimum of 10ga wire with a quality relay kit. Painless wiring sells an electric fan relay/fuel pump relay kit that will do the job well.

 

[luckythirteen13]

i didnt pull over because i was nearly home when i noticed it was one mark down from 270.
what about this one http://store.summitracing.com/defau...earchinresults=false&N=0&target=egnsearch.asp
that one from dc control is too expensive for me. you think the painless kit is any good? it looks as though it threads into the intake manifold. the one i have now has the heat probe in the radiator. which one is better? i need to decide soon cause now im carless

 

[Michael Yount]

I'm sure you'll do what makes sense to you -- but I'd leave you with this thought. The last 'inexpensive' system you put in just about caused you to burn up a motor. Lowest first cost is RARELY the best value. When it comes to keeping your car from overheating, spending a few $ more is a good investment. Good luck with it - and check that temp gauge more often - ESPECIALLY if you put an ineffecient relay-system back in it.

 

[kn7671]

Spending more on a quality part will usually leave you with a better quality product, but I've run the Painless Wiring Fan kit in 105F outside heat with an electric fan before and not had any reliability problems.