does anybody know if you can power these up without using the micro i have replaced the micro with an eliwell style controller the old micro and wiring to it were screwed hence having to do this modification,they have 4 wires earth and three others?
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does anybody know if you can power these up without using the micro i have replaced the micro with an eliwell style controller the old micro and wiring to it were screwed hence having to do this modification,they have 4 wires earth and three others?
the other wires are sensing wires for the micro ive done the same several times but i had issues with one of the fans on evap so i ripped out both on a 350 and fitted a pair of spalls as you no you can but 6 spalls for one carrier fan have you used a set of relays or the original board? i useually fit a 974 and 3 relays and a gah gd relay and do away with all the carrier control kit what do you useually do? going back to your original question 1 wire live 1 wire earth 1 wire micro sensing if it pohas a fourth wire its for variable speed/voltage for different speedfans with lenght of van if not adjustable onroof ta charlie
yes your right,974 3 relays +1 load relay [lucas] will the fan run if i just put power to the green and the heavy wire which i presume is the 12v pos feed.
put a continuity tester between the two wires that are the largest if you get continuity give them power and sea what they spin up like they dont like much more than 13volts they spin a bit fast and start burning up
will try maybe try to find a speed controller from rs?Quote:
Originally Posted by charlie patt
What was the fault with the old micro and harness?
I have had a recurring problem with a 12V Xarios 500, where the pins supplying the power to the evap fans would burn out. After doing a micro and later a harness, we learned that the only solution (OEM partswise, at least) is the replace the micro AND harness at the same time.
End result was a box, some relays and a few hours - left the micro in place and used the one remaining good output to switch the power for all three straight from the +12VDC rail, taking the load off the tiny micro pins.
In hindsight, being what it is, we now know that the relay path would have been the best option first up!
Try some nice chunky stud diodes, or a bridge rectifier, use them in series to give you voltage drop as required.Quote:
Originally Posted by cadwaladr
I upgraded a DC supply I built when the Owner wanted it fitted to a newer truck, which drew considerably more current for the evap fans. Existing rectifier arrangment couldn't take the heat (literally).
Moral of the story - HEATSINK, even when used for voltage drop.
well why did ctc not recall em in the early days,oh sorry they had to sell more micro,s
I bench test them using 2 of the wires for positive, 1 negative and leave the rpm sensing wire disconnected. Can't remember which though but can check if it helps. Seem to remember you can't test at full speed unless you use both the +ve wire and variable speed control wire.
what a thing to say the problem is its true. carrier recall is there such a thing they 500 pins are a bit like the new gah controllers and probes rubbish
I looked into replacing pins in the micro connector - the pin tool was 2/3 the cost of the harness... :eek: :eek:
thanks for the info will see it again tomorrow i have two old single fan evaps off 30s,another point are the defrost/hot gas valves n/o+n/c.
had a look at the old 30s motors today and now i know which 2 of three to link to make motors run the only issue now is the 2 solenoid h/gas valves.