512 bbi fansthey donbt come on help

good morning. i am needing help w/ troubleshooting my cooling system on my boxer. the fans do not come on when the car gets to temp. the cooling level is correct, the relays and fuses are all tested and ok.
the fans do come on when hot wired. where else do i look? has anyone gone through this before?

jr...you may remember my car ...you help advise me of what to do when i broke the main shaft. this car has been an ordel. i again appreciate and value your advice.

peter

Hi Pete,

Take a look at the thermo fan switch, on the lower left corner of the radiator. That is the switch that ultimately determines if the fans turn on. If the car is up to temperature...and you jumper the wires at the switch, resulting in the fans turning on, the switch is the culprit.

(When the radiator is at temperature (>180F), the switch should measure 0 ohms (shorted) with an ohmmeter.)

Regards,
David

thank you dave, this will be a great start in trying to fix this. i have had some tough issues to deal w/ over the last few years but hope to get them checked off 1 at a time! so nice to see you still have your bb and it's better and badder than ever so it seems. dave you and i met 10 or 12 years ago at a shelby event and if it means anything, seeing your car that day truely put me on track for boxer ownership!

i guess that means you are to blame! lol!!

thanks again dave,

peter

one comment,

with the key in the on position, jumping the two wires on the thermo switch will turn the fans on even cold....this prevents burning yourself on a hot radiator...

Pete,

Yes...I do remember meeting you at the Glen, but take no responsibility for your act of good taste! HA!!

These cars sure can be challenging to own, particularly geting the "bugs" out. I have had more than my share of issues to deal over the years, but have found the BB overall, to be extremely reliable.

Over the Summer, I'll be moving to Southern NH...Building a house up there, with a nice, large shop. If you on this coast with your BB, come on by, and I'll help you get her sorted out.

To clarify on the fan issue....As JRV stated, the fan circuit can be tested with the car cold. Just turn the key on, short the wires at the thermo-fan switch....and the fans should be running. Plain and simple!

Regards,
David

Hi Peter,

Nice to see you here,

I did just as David suggested when trouble shooting mine last summer, the switch was in a spot hard to access through the front grill so I needed to remove the front valance/bumper to access it,the BBis do have a shorter front grill with a fog light so it may not be an issue if it is, also you may be able to get around removing it with some creative tools.

jeff,

thanks again for the advice. between you, dave and jr...boxer ownership can really be made easier! even w/ the bugs to be worked out, i am still happy to have my baby back home!! i have owned my boxer for 4 years and 2 of them saw my car in the shop in the hands of a madman!! well it's home now and today i did the boxer owners typical thing...got up, pulled the cover off, fired it up and had a great drive to starbucks where it was parked outside in perfect sight so i could sip coffee and stare at my boxer. looking at that car over a great cup of java seems to make life seem a good thing!!!

jeff, btw, glad to see you here too. you were a great member of other sites and your going missing was puzzleing to be sure. truely glad your well and look forward to maturing our friendship!

your friend, peter

Pete,

Glad to hear you've got the BB back on the road again! Mine's been parked since late Novemeber...and the snow and salt on the roads just never seems to end!

If it's any consolation to you, it took me close to five years to get my car "fully" sorted...

Regards,
David

Thanks Peter,

I don't deserve to be referenced with David and JR when it comes to expertise on these cars, they really know their stuff which is nearly impossible to find today with them.

One note, I remembered the BBis have the fans behind the radiators so the fan switch may be located there and you might not have access issues to it as I have on my car as the fans and switch are in front.


Regards,

Jeff