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Coolant Fans on with ignition/Cold start issue
Posted: Tue Jan 26, 2010 6:37 pm
by busguy
My recently bought Bongo has the main coolant fans on with the ignition. The seller has had a new head put on and it runs well, and I need to find out if;
a) there is anything that can go wrong with the fan electrical system that would cause this, or
b) a previous owner (joker) just bypassed the thermostat control system for the fans?
I prefer to check a) first.
The other issue that might be linked to this is the Bongo does not start well. Could it be voltage drop when glowplugs need it most caused by the fans? The glowplugs are not very old and all glow red when removed and tested. Cannot see any shorting out. Linkage on pump moves when ignition switched on, but strangely drops back as glow plug light goes out, but before starting.
As you can see, I'm having a bit of fun but it is a good way of learning about Bongos.
Anybody got any experience or ideas on this? They would much appreciated.
John
Bognor Regis
Re: Coolant Fans on with ignition/Cold start issue
Posted: Tue Jan 26, 2010 6:45 pm
by missfixit70
Hi John, there's a recent thread with a similar problem that may give you some pointers -
http://www.igmaynard.co.uk/bongo/forum/ ... ns+running - try removing the fan fuses to see if it starts better maybe?
There's a list of fuses/locations in the members area, worth joining if you haven't already.
Welcome to the forum

Re: Coolant Fans on with ignition/Cold start issue
Posted: Tue Jan 26, 2010 7:17 pm
by haydn callow
Make sure the Air Con is switched off before starting......A/C on = rad fans on.
Re: Coolant Fans on with ignition/Cold start issue
Posted: Tue Jan 26, 2010 11:42 pm
by g8dhe
The Fans are controlled by the ECU so its not that easy to manually control them, other than by removing the Fuses as Kirsty suggests or un-plugging the relays.
Re: Coolant Fans on with ignition/Cold start issue
Posted: Tue Jan 26, 2010 11:44 pm
by missfixit70
Just make sure you re-enable them

Re: Coolant Fans on with ignition/Cold start issue
Posted: Wed Jan 27, 2010 4:23 pm
by busguy
Hi
Thanks for all the suggestions and I have had a good look at that previous posting.
Checked air con button is out/off before starting (it was), but another job, no light is showing when button pushed in/on.
Took fan fuses out and tried to start vehicle. Very marginally better without fans on but not right as took three goes, and runs rough. I thought the tickover speeds up for a time just after starting but this one sank to around 650/700rpm and wanted to stop. Going to check temp sensors when weather is better for driveway maintenance.
It will get bottomed, and thanks again to all.
John
Re: Coolant Fans on with ignition/Cold start issue
Posted: Thu Jan 28, 2010 12:50 am
by brorabongo
Worth checking the temp sensor which is on the head under drivers seat.
Heres a few photos....
This was causing my Brother-in-law's (oggy) radiator fans to run constantly from start up. The sensor had snapped off making it open circuit. So I would check that the sensor has been re-connected.... If it was disconnected for the job?
Re: Coolant Fans on with ignition/Cold start issue
Posted: Thu Jan 28, 2010 1:35 am
by cheffy34
Thats a damn clean looking diesel engine D
Re: Coolant Fans on with ignition/Cold start issue
Posted: Thu Jan 28, 2010 1:39 am
by brorabongo
Thats oggy's engine not mine. He did'nt have much luck with that bongo, but his latest from a well known dealer in Wigan has been a different kettle of fish, and it's restored his faith in Bongos.
Re: Coolant Fans on with ignition/Cold start issue
Posted: Thu Jan 28, 2010 11:25 am
by busguy
You guys are brilliant! That includes you Kirsty!
'brorabongo' hit it on the head and confirmed the temp gauge sender on the head as a possible cause which I said I was going to check in my comments last night after reading past postings. Thanks for the photos as they were really clear and helpful.
I had a look, all connections were in place with a new sender, so I thought .... no issues here, back to the drawing board! I decided to pull both connectors off and check pins, they were all in place and in good condition, so that's it then, depressed!

Put it all back in place and made sure all connectors were fully pushed home hard,................ and tried it.
It started straight away, fans off and running as sweetly as it should at around 900rpm with no smoke.
Obviously a connector not fully pushed home.
Thanks again for the help. Really appreciated.
John
[email protected]
Re: Coolant Fans on with ignition/Cold start issue
Posted: Thu Jan 28, 2010 3:21 pm
by missfixit70
Nice one, glad you got it sorted

Re: Coolant Fans on with ignition/Cold start issue
Posted: Thu Jan 28, 2010 4:32 pm
by brorabongo
busguy wrote:You guys are brilliant! That includes you Kirsty!
Your welcome. We all do our best to help if we can, thats part of what the forums about. These folk (and the fact sheets in members area) on here have saved me a small fortune over the years, giving me the know how, and thus the confidence to tackle the job.
Welcome to the forum by the way.
