205Si intermittent overheating problem
- Thread starter Langers
- Start date
There will be smoke if you do this and find it very difficult to get the escaped smoke back into the components.
The fans in an Si/late GTi/Mi16 are earthed the relay to switch them on. Early 205's are the opposite.
Here is the 405 wiring diagram. The Si/S3 205 is basically identical, except that the relays 733, 733A and 733B are grounded by the radiator switch rather than the Bitron H114. If you have a multimeter you'll be able to identify which of the three wires is earth.
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You don't need to pull anything apart yet. Just disconnect the thick yellow and red wires at the couplers and feed 12 V+ on red, minus on yellow. Each fan should have one of these couplers, so you will see if they go or not. Everything going well, warm up the engine to the point where fans should kick in, pull the connector plug off the switch and measure across the three contacts on the sender (Si should have the big doodad with three contacts). There should be one closed and one open or both closed contacts. Connenct respective wires as suggested above and you'll see what happens.
Leave the wires connected, but don't forget you did it.
If no luck, then it's off to check the relays. These are easily checked. Find the coil connection (usually pins 1 and 2), feed 12 V (doesn't matter how), you should hear clicking. If you can keep it powered, measure across the other pins. Relay closed should give you one contact on, one off, relay open should give you the same but the other way around. Repeat for all relays.
If these check out and still no luck, you need to check the feed off the fusebox. Identify at relays, identify at fusebox end and measure continuity between the two ends. Book gives wire numbers to make job easy identifying at fusebox end.
Check ground wire too.
If everything checks out and still no luck, I'm fresh out of ideas.
Leave the wires connected, but don't forget you did it.
If no luck, then it's off to check the relays. These are easily checked. Find the coil connection (usually pins 1 and 2), feed 12 V (doesn't matter how), you should hear clicking. If you can keep it powered, measure across the other pins. Relay closed should give you one contact on, one off, relay open should give you the same but the other way around. Repeat for all relays.
If these check out and still no luck, you need to check the feed off the fusebox. Identify at relays, identify at fusebox end and measure continuity between the two ends. Book gives wire numbers to make job easy identifying at fusebox end.
Check ground wire too.
If everything checks out and still no luck, I'm fresh out of ideas.
the fan relay setup is a pain in the ass. i dont have ac in my car anymore, so i simplified the setup (also due to one fan not operating after its removal)
yellow earth, one relay for each fan, radiator sensor connector, power supply for the fans via the relays, red one is the supply to the rad sensor (so it can switch the relays to operate) and down the bottom the 2 fan connectors. either one fan runs or 2 fans run in this setup. excuse the electrical tape, just an initial mockup, will do it properly when i stop procrastinating.
yellow earth, one relay for each fan, radiator sensor connector, power supply for the fans via the relays, red one is the supply to the rad sensor (so it can switch the relays to operate) and down the bottom the 2 fan connectors. either one fan runs or 2 fans run in this setup. excuse the electrical tape, just an initial mockup, will do it properly when i stop procrastinating.
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OK, so I undertook some troubleshooting this morning. Let's use the below images as a reference.
Relay numbers
Cooling fan temp sensor switch
Connector to cooling fan temp switch with pins labeled
Test results:
* Bridging pins 1 and 3 causes fan to operate at low speed
* Bridging pins 1 and 2 has no effect - no relay clicking, nothing
* Bridging pins 2 and 3 causes relays 1 and 2 to click, but the fans do not operate.
* Bridging all 3 pins together with a neat wire contraption I made causes the fans to run on high speed
Thoughts? Points to a temp switch failure for me...
Relay numbers
Cooling fan temp sensor switch
Connector to cooling fan temp switch with pins labeled
Test results:
* Bridging pins 1 and 3 causes fan to operate at low speed
* Bridging pins 1 and 2 has no effect - no relay clicking, nothing
* Bridging pins 2 and 3 causes relays 1 and 2 to click, but the fans do not operate.
* Bridging all 3 pins together with a neat wire contraption I made causes the fans to run on high speed
Thoughts? Points to a temp switch failure for me...
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OK so worked on the car yesterday and believe that the issue has been fixed – the low speed fans cut in and out when the coolant temperature is intentionally raised through revving at idle.
For future reference, it is not that hard of a job, although I did encounter some problems, namely that the Porters and Haynes manuals disagreed on the recommended sequence of events for filling and bleeding.
Some lessons learnt:
• Not all 205 raduators have a drain plug in place – mine was replaced a few years ago with what I suspect is an aftermarket part. I had to drain the radiator by removing the lower radiator hose on the driver’s side of the car (RHD car) and jiggle various piped around until the radiator drained properly. If you’re doing anything that involved draining coolant, it’s worthwhile checking whether your have a drain plug or not, and if not then may be worthwhile pre-ordering a lower radiator hose just in case you need to cut yours off. All this fiddling around and fighting to get the hose off added ~20 minutes and a lot of swearing to the job.
• The radiator fan thermoswitch came out quite easily, and was replaced just as easily. In order to get to the sensor, you need to remove the brackets that hold the power steering fluid reservoir and the fuse box. All are held on with 10mm bolts
• I removed some of the intake piping to make it easier to get to the bleed nipple on the thermostat housing
• The bleed nipple on the heater matrix return pipe was impossible to get to without moving the airbox across to the passenger side of the car and reaching in with very long needle nose pliers. Those without a strut brace in place or with smaller hands may be OK without disassembling the car.
• The Porter manual recommends filling up the expansion tank to 3cm above the max mark before running the engine up to temp. The Haynes manual said to fill to the max mark… I reckon Haynes was right as the bottle overflowed and spewed coolant everywhere…
• Warming the car up at idle is a very loud process that results in neighbours complaining and council rangers turning up in your driveway
For future reference, it is not that hard of a job, although I did encounter some problems, namely that the Porters and Haynes manuals disagreed on the recommended sequence of events for filling and bleeding.
Some lessons learnt:
• Not all 205 raduators have a drain plug in place – mine was replaced a few years ago with what I suspect is an aftermarket part. I had to drain the radiator by removing the lower radiator hose on the driver’s side of the car (RHD car) and jiggle various piped around until the radiator drained properly. If you’re doing anything that involved draining coolant, it’s worthwhile checking whether your have a drain plug or not, and if not then may be worthwhile pre-ordering a lower radiator hose just in case you need to cut yours off. All this fiddling around and fighting to get the hose off added ~20 minutes and a lot of swearing to the job.
• The radiator fan thermoswitch came out quite easily, and was replaced just as easily. In order to get to the sensor, you need to remove the brackets that hold the power steering fluid reservoir and the fuse box. All are held on with 10mm bolts
• I removed some of the intake piping to make it easier to get to the bleed nipple on the thermostat housing
• The bleed nipple on the heater matrix return pipe was impossible to get to without moving the airbox across to the passenger side of the car and reaching in with very long needle nose pliers. Those without a strut brace in place or with smaller hands may be OK without disassembling the car.
• The Porter manual recommends filling up the expansion tank to 3cm above the max mark before running the engine up to temp. The Haynes manual said to fill to the max mark… I reckon Haynes was right as the bottle overflowed and spewed coolant everywhere…
• Warming the car up at idle is a very loud process that results in neighbours complaining and council rangers turning up in your driveway
Yeap, it could. It can be other things too, but the easiest thing to do is replace the relays with good ones and trying that. I would try replacing them one by one to see which one makes a difference, maybe not all relays are bad.
When burping the air out of the system on a 205 si, you need to lift the bottle up really high. Remove the rubber strap and make a hook out of a coat hanger and hang it from the bonnet edge. (ie eye level).
Worth checking the small hose from the top of the radiator to the filler tank, they block up with junk.
Also, you can always just press the ac switch on in traffic, turns the fans on as well and drops the temp.
Worth checking the small hose from the top of the radiator to the filler tank, they block up with junk.
Also, you can always just press the ac switch on in traffic, turns the fans on as well and drops the temp.
I popped into Repco and they couldn’t seem to find an equivalent Narva part, had 20amp and 30amp but not 25 for some reason. Is their OEM relay (g.Cartier) the only option?
Good idea. Will check that thanks
I think the fans are still controlled by the relays so if they're not good, using the A/C button is not going to do anything. Besides, you should by now know if the fans come on when the A/C is on if you've used the A/C before. If they do, then the relays are not your problem.
The Cartier relay is thankfully not the only option. It is just a relay brand, others are the same or better. 30A is going to be fine, probably better. I uprated mine to 100A but I have changed the wiring too, and my wires are individually hooked directly to the battery. Heavy gauge silicone insulated so if they melt, the insulation won't. No problems so far.
Another problem I have had is the radiator mounted switch which burns out because it is not properly designed or made. Not sure which, but I have had two brand new OEM units fail the same way in a very short time. Water crept in where the metal is crimped onto the plastic and the contacts inside corroded until they probably could not carry the current anymore and burnt. I know because I have opened both to see what the problem was. Corrosion and signs of sparking were obvious.
I replaced the two position sender with a single position sender (still an OEM part but for Peugeot 504 - same thread, same temperature) and now my fans come in full speed, both at the same time as soon as the switch closes. I think this is a much better setup for our climate anyway. Result is immediately visible when the fans kick in. I also modified the wiring so the switch triggers two relays and each relay takes care of one fan only. Much simpler, much more beefy and so far much more reliable.
The Cartier relay is thankfully not the only option. It is just a relay brand, others are the same or better. 30A is going to be fine, probably better. I uprated mine to 100A but I have changed the wiring too, and my wires are individually hooked directly to the battery. Heavy gauge silicone insulated so if they melt, the insulation won't. No problems so far.
Another problem I have had is the radiator mounted switch which burns out because it is not properly designed or made. Not sure which, but I have had two brand new OEM units fail the same way in a very short time. Water crept in where the metal is crimped onto the plastic and the contacts inside corroded until they probably could not carry the current anymore and burnt. I know because I have opened both to see what the problem was. Corrosion and signs of sparking were obvious.
I replaced the two position sender with a single position sender (still an OEM part but for Peugeot 504 - same thread, same temperature) and now my fans come in full speed, both at the same time as soon as the switch closes. I think this is a much better setup for our climate anyway. Result is immediately visible when the fans kick in. I also modified the wiring so the switch triggers two relays and each relay takes care of one fan only. Much simpler, much more beefy and so far much more reliable.
This link (it's a long one) will take you directly to a list of fan types post 1991 XU models. Copy and paste.
OEM numbers and fan thermostat details are there for most of them.
If your model is earlier or a different engine variant go to the catcar homepage for Peugeot (below), select the model 205 and open the relevant link to the diagram of your model.
For example my 309 pre 1991 XU5 JA (B6D) 1.6 injection 113hp has 1264 21 97/92 degrees
If the 6 figure OEM number is no help at the parts store at least the on/off temp can guide them.
A search for an OEM number should bring up lots of listings on ebay and various northern hemisphere parts suppliers. Some of the search results will give thread dimensions will also help at your local parts store.
I have attached a screen shot from servicebox that show many temp listings for 309 XU5. It might help you identify your specific thermo.
Some models run two stage thermostats which I am unfamiliar with.( 1264 22 97/92 - 101/96 degrees) Two-stage fan speed or one fan and then the other?? I am not sure.
Perhaps the manufacturer of your present thermo. switch has stamped the temp. rating on the brass fitting.
OEM numbers and fan thermostat details are there for most of them.
If your model is earlier or a different engine variant go to the catcar homepage for Peugeot (below), select the model 205 and open the relevant link to the diagram of your model.
Peugeot - Catcar.info
www.catcar.info
For example my 309 pre 1991 XU5 JA (B6D) 1.6 injection 113hp has 1264 21 97/92 degrees
If the 6 figure OEM number is no help at the parts store at least the on/off temp can guide them.
A search for an OEM number should bring up lots of listings on ebay and various northern hemisphere parts suppliers. Some of the search results will give thread dimensions will also help at your local parts store.
I have attached a screen shot from servicebox that show many temp listings for 309 XU5. It might help you identify your specific thermo.
Some models run two stage thermostats which I am unfamiliar with.( 1264 22 97/92 - 101/96 degrees) Two-stage fan speed or one fan and then the other?? I am not sure.
Perhaps the manufacturer of your present thermo. switch has stamped the temp. rating on the brass fitting.
Hi Peter, do you know the part number of the sensor is or temp range please? I’m assuming it’s “1264…”
126445 would be my pick. Make sure you also have a 92º thermostat to match. You can choose a lower temp switch, but always have to match the thermostat.
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Find many great new & used options and get the best deals for TP Radiator Fan Temperature Switch Fits CITROEN ZX PEUGEOT 205 306 405 126445 at the best online prices at eBay! Free shipping for many products!
www.ebay.com
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Thanks Peter126445 would be my pick. Make sure you also have a 92º thermostat to match. You can choose a lower temp switch, but always have to match the thermostat.
TP Radiator Fan Temperature Switch Fits CITROEN ZX PEUGEOT 205 306 405 126445 for sale online | eBay
Find many great new & used options and get the best deals for TP Radiator Fan Temperature Switch Fits CITROEN ZX PEUGEOT 205 306 405 126445 at the best online prices at eBay! Free shipping for many products!www.ebay.com