Car horn

#1
My car horn ( 3500 auto) sounds very small sounds like only one working.
Would it be dual horn and where are they located. New owner , and no nothing .
Ps want to change/ upgrade all 4 headlights as they are original only 1 works. Best place to buy new upgrades please and do they just swap straight over.
Thank you all for your time
 

jp928

Active Member
#2
There is one horn in each front corner, and your symptoms exactly match the case of one being dead. They are marked as a low note and high note. Easiest to find is near side behind the headlights. One of mine was dead - had water in it at some time, rust. A good clean, bit of abrasion on the points, working again. Replaced the rivets with M5, or M6 cap screws, nylocs. Removal is probably easiest from underneath, certainly for the off side unit.
Lights - any good 5-3/4 body designed for H4 bulbs should do the job, or sealed beams. The 75W high beam bulbs may not be common - single filament, 2 pins. The low beams are 37.5/50W, 3 pins.
 
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#3
JP is correct . horns are one each side reached form underneath .better if u can raise front a bit such as car ramps but these can get in way a wee bit so ideally axle stands .have peek first. might be a case corrosion pithing unit as was one of mine! bought new horns and sold boot sale as unopened after I removed and stripped horn. cleaned off corrosion and rebuild tested ..still woking and that was 3 years ago. Headlights not look into as all mine work though do see how dim they are compared to modern stuff. as I never use main beam. I might replace just a pair. will look into whats out there and recommendation form rover p6 groups. bear in mind LED are not probably going to get through an MOT.
 
#4
There is one horn in each front corner, and your symptoms exactly match the case of one being dead. They are marked as a low note and high note. Easiest to find is near side behind the headlights. One of mine was dead - had water in it at some time, rust. A good clean, bit of abrasion on the points, working again. Replaced the rivets with M5, or M6 cap screws, nylocs. Removal is probably easiest from underneath, certainly for the off side unit.
Lights - any good 5-3/4 body designed for H4 bulbs should do the job, or sealed beams. The 75W high beam bulbs may not be common - single filament, 2 pins. The low beams are 37.5/50W, 3 pins.
Thank you sir
 
#5
JP is correct . horns are one each side reached form underneath .better if u can raise front a bit such as car ramps but these can get in way a wee bit so ideally axle stands .have peek first. might be a case corrosion pithing unit as was one of mine! bought new horns and sold boot sale as unopened after I removed and stripped horn. cleaned off corrosion and rebuild tested ..still woking and that was 3 years ago. Headlights not look into as all mine work though do see how dim they are compared to modern stuff. as I never use main beam. I might replace just a pair. will look into whats out there and recommendation form rover p6 groups. bear in mind LED are not probably going to get through an MOT.
Thank you sir
 
#9
Many thanks , was a very easy fix thanks to everyone's help , only a lose conection at the horn. All done and now it's back to dual. Thanks for all the replies :thumb:
 

Peterv

Active Member
#11
I replaced my headlights with Hella units. The outers with a high/low hardened glass unit and the high beam inners with a long range pencil beam. This way the high beam on the outers light the general area and the pencil beam covers the far away stuff. If you have your headlights supported with relays you could put some serious wattage halogen globs in them otherwise just stick to standard wattage globes so as not to risk overloading the antique wiring, fusing and switch contacts. There's more info on this topic elsewhere on this forum. (I do very little night driving but when I do its great to see what's ahead)
 

GRTV8

Well-Known Member
#12
We' [NZ] have just gone into a country wide Covid lockdown.
Needed to escape the impending boredom and was inspired by your horn refurbishment.
Drivers side was dodgy so pulled it out. Removed quite easily from under the valance.
Very oil/dust encrusted. 50yrs accumulation.
A cleaned up body showed the manufacture date. I bought my P6b new in Nov 72.
It sort of works so Im not too keen to break it apart.
Will try WD40 down the trumpet and bench test tomorrow and see if it improves.
Gerald
 

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Peterv

Active Member
#13
Hi Gerald
When I first got the car, my H9 horn set sounded like a goose being strangled. Got them on the bench, cleaned them up and re-tuned them. Easy to do by undoing the big lock nut and adjusting the centre screw. You'll need a 12v power source, like a battery and some bits of wire. Take care when the wires are attached to the battery not to short them out. One horn will have a high tone, the other a low. Just adjust them till they sound right as a pair. (suggest wearing ear muffs and shutting the doors so as to not upset the neighbours when tuning) Then lock the big nut and retest as sometimes locking will alter the tone a bit.
Easy peasy.
 

GRTV8

Well-Known Member
#14
Hi Gerald
When I first got the car, my H9 horn set sounded like a goose being strangled. Got them on the bench, cleaned them up and re-tuned them. Easy to do by undoing the big lock nut and adjusting the centre screw. You'll need a 12v power source, like a battery and some bits of wire. Take care when the wires are attached to the battery not to short them out. One horn will have a high tone, the other a low. Just adjust them till they sound right as a pair. (suggest wearing ear muffs and shutting the doors so as to not upset the neighbours when tuning) Then lock the big nut and retest as sometimes locking will alter the tone a bit.
Easy peasy.
Hi Peter
Sounds too easy -thanks. I will squirt a bit of WD40 under that big adjusting screw too.
great lead
thanks
Gerald
ps. do you know what the smaller grub screw adjacent to the adjusting screw is for?
 
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GRTV8

Well-Known Member
#16
The small grub screw adjusts the contact breaker for wear.
Thanks Demetris
I havnt been using my P6 as a Philipino Taxi ,so Im assuming the contacts will still be good.
Without opening up the unit, the inside condition is subjective.
If my WD40 route doesn't work I'll have to do the "Telvis" thing and open it up. Pity the unit is riveted together. I guess Rover weren't expecting their cars to stand the test of time.
 

Demetris

Well-Known Member
#18
Gerald, if you have time on your hands, it is quite rewarding and easy to do a proper restoration on them. Open them up, clean everything inside, close again with screws and nuts, paint, adjust. I must have done about haf a dozen of them in the past. But if you are not inclined, you could always try some bench adjustment, and see if they respond.
 

GRTV8

Well-Known Member
#19
Hi Guys
All good information -thanks.
Well as its turned out ,I sprayed ample WD40 into the trumpets.
Gave the outside a whack with the hammer. Not hard enough to break the caste.
Let it soak overnight.
Bench tested.
BLAAAR.
Four neighbours turned up to see what was going on.
I'll go to stage two and dis assemble if this method fails in the next short while.
Once again thanks for your input.
Gerald
 
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