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Heat not hot enough

Hooli

Re: Heat not hot enough

Postby Hooli » Sun Dec 02, 2012 6:17 pm

I wish I'd sat around longer before starting the job, took me a while to find that brown connector. I had to refer to a wiring diagram to check what I was looking for! Obviously I hadn't seen your reply till I got back in.
It was the fusebox like you said. I had 3.5v getting to the blower, as soon as I resoldered it (& the other two dodgy connections I could see) the RH blower works. I don't know if it works on the lower speeds as I didn't run the car to check. Either way I've got enough hot air blowing around to get the car warm now.

As for the Fiesta, I found loads of misrouted wiring melting onto the engine & the throttle body with 1/4" of play in one of the retaining bolts. It's running better now, but still isn't right. It's damn annoying as we paid to get the head gasket done to save any hassles from it not getting done right. I should have done it myself as it's going to be a real pain getting the money back off the idiot now, let alone getting it to run right.

naki_k
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Posts: 27827
Joined: Sun Feb 21, 2010 9:25 pm
Location: Kirton, nr Boston, Lincolnshire

Re: Heat not hot enough

Postby naki_k » Sun Dec 02, 2012 6:48 pm

as a general rule, its well worth resoldering the WHOLE fusebox, both left and right. at this age, when one joint has cracked, chances are others are on the way.
glad you cracked it quickly anyhow. now you need to check all the fans speeds. could still be an issue there.
as i said before, when i was sorting the heating on mine, three separate issues conspired against me.
lack of power the blowers, faulty climate ECM, and darlington transistors :roll:

if you know that the LH & RH fuseboxes are completely resoldered, its a much better starting point to solve any future electrical issues. or you may not even have anymore once that is done. cant stress how important it is.
Last edited by naki_k on Mon Dec 03, 2012 5:13 pm, edited 1 time in total.
88 3.6 XJ6 PDH/CEM
90 Range Rover Vogue SE 3.9 V8 LPG
91 3.2 XJ6 SportPack Manual
91 4.0 XJ6 Manual
92 4.0 XJR Manual
92 4.0 XJR
93 3.2s - 4.0 Manual conv
93 4.0 Sovereign
93 6.0 XJ81 DD6
93 6.0 XJ81 XJ12
94 4.0 XJR
96 4.0 X306 XJR
96 4.0 X300 D6
97 4.0 X300 Sport Manual
2000 LR Discovery ES TD5 A
Breaking 40/ 300

Hooli

Re: Heat not hot enough

Postby Hooli » Mon Dec 03, 2012 3:37 pm

I do agree with that idea of resoldering the lot, however till I get a new tip for my soldering iron I'll leave it as the finished job looks cruddy currently.

Hooli

Re: Heat not hot enough

Postby Hooli » Wed Dec 05, 2012 2:01 pm

Mmmmm warm this morning, forgot to check the lower speeds though.

rvdz-dummy
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Re: Heat not hot enough

Postby rvdz-dummy » Fri Mar 01, 2013 7:53 am

one thing you can do to know whether hot water is getting through to the matri

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naki_k
Super Moderator
Posts: 27827
Joined: Sun Feb 21, 2010 9:25 pm
Location: Kirton, nr Boston, Lincolnshire

Re: Heat not hot enough

Postby naki_k » Fri Mar 01, 2013 11:03 am

JasonRain wrote:one thing you can do to know whether hot water is getting through to the matri

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I assume you are asking a question here?

Remove the left side knee bolster, and you can see the two water pipes entering the heater matrix. Just put your hand near them or touch them quickly. You will know if they are hot!!!

Or a quicker way to feel the rubber pipes on the engine bay side of the bulkhead.
88 3.6 XJ6 PDH/CEM
90 Range Rover Vogue SE 3.9 V8 LPG
91 3.2 XJ6 SportPack Manual
91 4.0 XJ6 Manual
92 4.0 XJR Manual
92 4.0 XJR
93 3.2s - 4.0 Manual conv
93 4.0 Sovereign
93 6.0 XJ81 DD6
93 6.0 XJ81 XJ12
94 4.0 XJR
96 4.0 X306 XJR
96 4.0 X300 D6
97 4.0 X300 Sport Manual
2000 LR Discovery ES TD5 A
Breaking 40/ 300

dstary
Posts: 22
Joined: Fri Feb 05, 2016 11:19 am

Re: Heat not hot enough

Postby dstary » Sun Jul 29, 2018 10:31 pm

Good morning all,

Just thought I’d post a reply to this pretty old thread in case someone else comes across it trying to fix a weak heater like I was.

I have a ‘94 Daimler Double Six (XJ81), and I was finding the the heater was weak at best, freezing cold at worst on my morning commute. I tried most of the fault finding listed (checking heater control panel operations, removing and cleaning lower blend flap motor, then replacing same motor a few weeks later, checking heater valve operation, checking temperature of heater matrix in and out piping etc), and the heater would sometimes seem ok, other times it returned to its old tricks (I.e no heat).

In the end, I realised that the heater was appearing to work ok when testing it in the driveway, and when caught in traffic, but once the car was running fast it was cold. The temperature gauge in the dash tended to read around N at all times, albeit dipping a little lower in these cold mornings (-5C). So this weekend I dove in and replaced the thermostats. A couple of genuine EBC3577 at 88C each replaced what looked like generic 82C stats, one of which was jammed open, and a few hours later (add a radiator flush, run for 30 mins, drain coolant, flush with water, drain water, add fresh coolant and demineralised water) the job was done. I managed to get 8.5L of concentrated coolant, plus around 9L of demineralised water into the old V12.

In terms of general running, I really noticed no difference, but the heater was transformed! The drive in this morning was a joy, with consistently hot air available on manual, and proper operation while in auto. So, if you are suffering low heat, it may be worth having a look at your thermostats too!

Dave
1985 XJS HE (manual conversion)
1994 Daimler Double Six (XJ81)


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