shaw109

Hi all i have a mk5 1.3 escort and the heater has stoped working
but this is what i have checked i have checked the switch in the dash and it is reading 10.55 volts the main fuse box is reading 11/12 volts and the fuse has not blown, the main plug on top of the heater blower is reading 5/6 volts is this to low and if it is what is caseing it and how can i put it right?? i have also ran a test wire to the heater blower and it works fine on all three speeds so i know its not the blower and the horn has also gone very weak it hardly makes a noise could this be a bad earth mybe any help with this will be great as i have hit a wall and it is driving me mad many thanks shaw109

tabetha

If horn and heater are on the same FUSE check here for a corroded fuse first, heater earth will be seperate to the horn.
When you say stopped working you mean the motor, I assume (?).
The switch works by sending the currect to each position of the RESISTOR pack on the heater blower motor, your readings are very low, I would clean up all the battery connections as well just so they can be ruled out.
Is it just one particular speed it does not work at, if so it will be a broken resistor pack wire, most blikely or a break in the wire between it and the switch.
What is the battery voltage with engine off and engine running ?
You sound like you know what is what lecky wise so will not be a hard fix.
DC motors(heater blower) are exceptionally voltage sensitive, so make sure you have decent volts to start with.
tabetha

shaw109

Hi tabetha the horn and the heater are on different fuses ,but on useing the test wire the blower works on all three speeds so i know its not the blower, just tested the feed to the horn thats only reading 5/6 volts as well ??? am i right in thinking that there must be a break in the wire or has the fuse box gone???? i know the mrk 5 fuse boxs the solder drys out then thats when you start getting the props.

Phil DJ

Try running some wire from the fuse box to the horn and see if it works then. At least you can elliminate a break in the wire if you do it that way

shaw109

Hi phil thanks mate will go and do that now as am going to triy and trace the wires and see if i can sort it out if not its going to have to go to someone that nows what thay are doing lol to be done sham a hate things beating me will put a post up if i sort it or not??? thanks again shaw109

tabetha

It is easy to trace the high resistance that is causing this just very time consuming.
There is obviously a point where the power is fed after the igntion switch to various components, including one point that feeds these two things, that point has to be between the ignition switch and the fusebox, it could be a corroded bus bar for example, or a soldered joint, or course a simpler way around it some have done is to go to the underside of the fusebox, and reroute another live fed from the ignition switch to the input side of the fuse holder(blower fan), to restore it to full 13/14 volts, that will of course restore any ohter circuit that is joined to it ie the horn also.
I don't do it this way but can see why some do, other wise it is a case of following the harness to see where joins are.
tabetha

shaw109

hi tabetha horn sorted now bad earth cleaned off and all ok but as for the heater still no luck what is a bus bar this all started when wifey turned the switch in the dash far to fast and nothing happend but it did not blow the fuse so this bus bar is sounding more like the problem do you now what it looks like and where it is sorry to ask but this is realy winding me up now many thanks again shaw109