[jerseybean]

hi everyone iv got a 98 puma and am now getting the good old problem of it over heating and unable to trace whats causing the problem, so far i have checked the fuses, changed relays but not really sure which 1 does the cooling fan, put a 12v supply to the fan and thats ok, thermostat has been taken out, also on advice from my local ford dealer to change the sender unit below the coilpack which apparrently goes to the ecu which will then tell the fan to switch on(is this correct or are they telling me porkies? ), havent checked the hcv or the resistor on bottom of fan housing yet but is my next port of call.

if im thinking correctly the hcv is ok coz am able to get cold air thru the vents and also hot air so im assuming the hcv is ok unless sumone can correct me on that 1, and the resistor on the bottom of the fan housing is for when i use the aircon.

Whilst i think bout it just a quick question on the aircon is when im using it does the fan come on straight away coz the reason for asking that is that its not (or am i barking up the wrong tree ) and the revs are jumping up to bout 2500rpm and pretty much back down to 250/500rpm which to me isnt right at all even though i know that the revs will pick up slightly when the aircon is used, could this part of the problem with the puma overheating in sum way?

Any advise on any of the above would b most appreciated coz am now startin run out of ideas

Thanks in advance

[happy-kat]

Hi
have a read of these articles clicky me

[jerseybean]

cheers but looked at them after posted, it confirms what i mentioned bout the hcv and i was correct on how it works & its working fine but still nufin on there to explain what else to check.

Not wanting to take it to the garage iv been looking in the haynes manual for 95-02 fiesta which iv heard u can base the puma on & looked at the wiring diagram for the cooling fan which shows the relays in the auxillery compartment but doesnt say where the exact position for the fan relay is so anyone who could help on that would b great, otherwise further back in the manual it says the fan is run by the PCM which im taking its talkin bout the ECU which if it is it looks as if i could b botching in a 12v supply on a switch to the fan & running it that way which im not wanting to do but if push comes to shove im gonna have to go that way for now untill iv got the money at a later date

[pumapilot]

If your 98 Puma is on its original HCV & still going, then consider yourself lucky = #1 culprit i reckon.

[happy-kat]

From the Gallery

[jerseybean]

i think its still on the original HCV and im getting cold air when on cold & hot air when on hot so far as im concerned its working ok, but cant really see why that would make the puma overheat coz it only diverts the coolant either thru the heater matrix when you want hot air & stops it passing thru the matrix when u dont so can understand that if it was faulty i would be getting just hot or just cold air thru the vents, does the HCV have another function that i have overlooked?

[marc t]

If you have AC, when ever the AC button is lit up the fan should be on the slow speed. If the resistor has gone, the high speed will kick in and out every so often with the AC on.

With the AC off, you should have a low speed then when it gets really hot the high speed should come in. I think it was about 110c ish. - If you have the digitial dash select the temp read out and monitor what sort of temps you are getting. I know I posted up somewhere on a few posts which temp the fans cut in at.

When you removed the stat, have you an air lock as this would cause issues

Also, don't rule out the HCV, it could be sticking between hot and cold and restricting the flow.

The temp sensor does send a feed to the ecu which controls the fan so Ford were telling the truth.

Here are some posts I have put various info on regarding the temps and how to fix the resistor if its just the temp fuse to save buying a new one. You can also bridge the two wires on the resistor. This would mean if this was faultly the fan would cut in on the high speed for either option to to check if the fan works.

http://www.pumapeople.com/forum/index.php?...c=91717&hl=

http://www.pumapeople.com/forum/index.php?...c=85173&hl=

http://www.pumapeople.com/forum/index.php?...c=83643&hl=

http://www.pumapeople.com/forum/index.php?...c=83321&hl=

Hopefully these may help.

[jerseybean]

unfortunatly by the looks of it that fusebox set up is different to mine so the relays are more likely in a different position but cheers anyway happy-kat... will have to get a pic of the fusebox 2moz and post it up and hopefully sumone will reconise where it would be, & thanks marc t... those links have helped but will have to wait till 2moz to double check relays & most prob go down to ford & get a HCV just so i can eliminate that out of the way & have piece of mind that it wont play up on me in the near future

This post has been edited by jerseybean: 28 July 2009 - 08:35 PM

[YOG]

i think its still on the original HCV and im getting cold air when on cold & hot air when on hot so far as im concerned its working ok, but cant really see why that would make the puma overheat coz it only diverts the coolant either thru the heater matrix when you want hot air & stops it passing thru the matrix when u dont so can understand that if it was faulty i would be getting just hot or just cold air thru the vents, does the HCV have another function that i have overlooked?

From another car forum:

How does the heater control valve cause overheating faults, surely the water will still circulate but not through the matrix?
"It's the weird stat arrangement. The wax pellet faces the radiator, not the hot flow from the head, creating a Catch-22 scenario that the wax pellet only gets hot water to open it - once the stat has been opened.
To get round that issue, the heater return flow was plumbed all the way around the engine bay just to warm the back of the stat. Once the heater valve sticks half-way, it doesn't feed enough hot water to the stat and so it doesn't open properly - just as a fitted-the-wrong-way-round stat wouldn't.
The heater valve also contains a by-pass valve and either feeds the matrix or diverts the flow back into the thermostat housing where it goes past the wax-pellet end of the backward-facing stat and heats it. The faulty one appears to have come apart and blocks off both ways at once: hence the difference in temperature of the heater hoses in and out and the cause of the problem."

[PatchPuma]

When my HCV went on my 99' Puma, I was still getting hot and cold air from the vents, so don't rule out the HCV

[jerseybean]

Right went out and bought a new HCV today to replace the old one that could be giving me my troubles but unfortunatly that hasnt made any difference & iv still have no rad fan turnig on when gets hot & over heats, even when got the a/c on it doesnt work even when the car is cold

so far iv done:
1-checked all fuses
2-got new fan relay
3-12v supply to fan to see if works & it does
4-changed temp sender underneith coilpack
5-new HCV
6-thermostat taken out
7-checked for airlocks dont seem to be any signs of one(all hoses are nice and hot

only things left that know of are:
1-the fan resistor
2-check the ECU to see if thats giving the problem
3-check for breaks in the wiring sumwhere

just to check bout the fan relay to see if right one has been changed... when you look into the auxillary fusebox iv got 3x bright green relays rated at 30/40amp, 1x black relay rated at 70amp & 1x dark green relay rated at 70amp my local ford dealer supplied me with 1 of the bright green relays rated at 30/40amp & was wondering if it might of been the wrong one & should of been supplied either the black or dark green 70 amp relays or both as these are sat next to each other & as iv got a/c iv seen in other posts that there is a relay for low speed & one for high speed could my thinking be right that these 2 70amp relays are for the fan speeds which arent telling the fan to work

Going to a friends workshop 2nite & gonna test if any voltage is bein sent to the fan & if so what amount, then hopefully test the resistor so will report back 2moz if anything was found

If anyone can figure out what the problem is or even suggest sumfin else to check please let me know coz its getting annoying that nufin seems to be working

Cheers

This post has been edited by jerseybean: 29 July 2009 - 07:00 PM

[Miffi]

might be the alternator. I was getting intermittent voltage surges through it which caused blasts of really hot air to be sent into the car, regardless of what the temp control was at. Replaced the alternator (after getting a new HCV which didn't make any difference!) and it's been fine since then, Worth thinking about.

[hulkster]

Is stat right way round? bulb part faceing the block not the rad.

On ECU connector(C159)
pin 38 connects to (C158) pin6 connector behind drivers headlight then connects to temp sender.
pin 68 output to engine cooling fan (K45)
pin 17 output to high speed cooling fan (K46)


Is the cooling rad partly blocked? when my fan seized drove round on normal runs for about 3 weeks without it boiling just the flow of air when driving was enough to keep the engine at normal temp, it was only sitting in traffic for more than 15 mins when i had problems.

Info on Relays looking on tech drawing - three electric connectors at the back
Engine cooling fan relay K45 (4th from the left between row of connectors & row of fuses)
High speed engine cooling fan relay K46 (5th from the left between row of connectors & row of fuses)

On ECU connector (C159)
C159 pin 38 connects to (C158) pin6 connector behind drivers headlight then connects to temp sender.
C159 pin 68 (output) to engine cooling fan(K45)
C159 pin17 (output) to high speed cooling fan (K46)

Hope this helps

[jerseybean]

thanks everyone for all the exellent advice found the problem in the end ... it was the fan resistor .


Thanks again guys

[TrUeJaY]

wheres that ... how much does it cost to replace that?

[jerseybean]

wheres that ... how much does it cost to replace that?

fan resistor is on the bottom of rad fan housing righthand side looking down from above, cost me £36(no vat) from local ford dealer. Once you have found where its located its easy to replace just by jacking up the front of the car disconnect the plug from it and with a dumpy no.2 philips screwdriver undo the 2x securing screws and it will pretty much just fall out then basicly refit it in reverse of how you took it out. No point taking it to sumone to do just for a 10 min job and its that easy to do a 5 year old could practicly do it

This post has been edited by jerseybean: 03 August 2009 - 01:16 AM