{"id":844,"date":"2023-12-01T16:14:58","date_gmt":"2023-12-01T16:14:58","guid":{"rendered":"https:\/\/int03.co.uk\/blog\/?p=844"},"modified":"2023-12-01T16:35:39","modified_gmt":"2023-12-01T16:35:39","slug":"abarth-fiat-500-wiper-motor-fault","status":"publish","type":"post","link":"https:\/\/int03.co.uk\/blog\/2023\/12\/01\/abarth-fiat-500-wiper-motor-fault\/","title":{"rendered":"Abarth \/ Fiat 500 Wiper Motor Fault"},"content":{"rendered":"\n

I was driving on the motorway in heavy rain, when my windscreen wipers started working intermittently, then suddenly stopped completely! This was pretty scary as visibility was almost zero. Fortunately I was close to a slip road and services, and pulled off into the service station car park. Ultimately I had to call my breakdown insurance and, as they couldn’t fix the fault at the roadside, had to get the vehicle recovered.<\/p>\n\n\n\n

Assuming this was a wiring fault, I decided to take a look at it myself…<\/p>\n\n\n\n

To gain access to the windscreen wiper motor and its wiring, you first need to remove the plastic scuttle panel<\/a> beneath the windscreen. It’s worth watching the video linked above before attempting this, to know what you are getting into!<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

There are two plastic trim panels covering the wiper arms, which need to be removed (pull up on the right side of the panels, as the left side hooks in). You need to remove the dust covers on the wiper arms, and undo the two nuts to remove the wiper arms. The panel itself is secured with two plastic clips and a small Torx screw in the front centre. There are another two clips holding the panel at the top left and right, and further plastic clips secure it to the window. Too much to explain here, so please do watch the video linked above before you attempt it!<\/p>\n\n\n\n

Having removed that, you can access the wiper motor as shown below:<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

The whole wiper motor assembly is held on with two bolts, and easily removed with a 10mm socket. There’s a 4-pin connector which unclips and pulls free. The connector has a Ground connection, two Motor connections (for the two speeds), and a sensor output (pulled to Ground when the motor is at the start position).<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

After disconnecting the motor, I used a Multimeter to check for 12V on the two motor pins, and found there was power on both pins when selecting the appropriate wiper speeds on the stalk. On mine, the Ground wire is black, and you can spot the Sensor wire because it is thinner than the others. The two thicker wires on the outside of the connector are the Motor connections:<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

As there was obviously power on the connector, this seemed to confirm it was the motor itself at fault, rather than the wiring as I had first suspected.<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

The motor is made by DENSO and the part number is MS159200-8660. The same part appears to be used on Fiat 500 and the Ford Ka Mk2. Used ones cost about \u00a325 and new ones cost about \u00a380-\u00a3120.<\/p>\n\n\n\n

I ordered a secondhand one, but was still curious to know why the motor had failed, so decided to open it up. The plastic cover clips on and you need to be really careful not to break the plastic clips when removing it as they are very weak. Inside, I found that the Ground connection had a poor solder joint on the PCB, which had caused it to fail, and it was no longer physically attached to the PCB.<\/p>\n\n\n\n

Here’s a picture of the underside of the PCB, showing where the Ground connection was originally (supposed to be) attached:<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

Here’s the ground connection pin, which is supposed to be located in the black plastic pillar at the top of the board, next to the two motor connections:<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

Here are some images of the PCB front and rear (taken before the repair, so the ground connection is missing in these photos. Is just my strange sense of humour, or does this PCB look like a bit like a cow?<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

This actually looks like a pretty well designed part, but it was sadly let down by one poor solder joint. The circuit is very simple: the pins are connected directly to the motor and switch contacts, and each motor has a capacitor and what looks like a TVS diode to suppress voltage spikes.<\/p>\n\n\n\n

To fix it, I cleaned up the tip of the Ground connection carefully with a small file on both sides, then soldered it back into the board. I also applied some new grease to the motor worm drive and the plastic gear wheel. After reassembling it, the unit works fine again.<\/p>\n","protected":false},"excerpt":{"rendered":"

I was driving on the motorway in heavy rain, when my windscreen wipers started working intermittently, then suddenly stopped completely! This was pretty scary as visibility was almost zero. Fortunately I was close to a slip road and services, and pulled off into the service station car park. Ultimately I had to call my breakdown … Continue reading Abarth \/ Fiat 500 Wiper Motor Fault<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17],"tags":[5,13,6,7,11,12,15,8,9,10],"_links":{"self":[{"href":"https:\/\/int03.co.uk\/blog\/wp-json\/wp\/v2\/posts\/844"}],"collection":[{"href":"https:\/\/int03.co.uk\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/int03.co.uk\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/int03.co.uk\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/int03.co.uk\/blog\/wp-json\/wp\/v2\/comments?post=844"}],"version-history":[{"count":6,"href":"https:\/\/int03.co.uk\/blog\/wp-json\/wp\/v2\/posts\/844\/revisions"}],"predecessor-version":[{"id":860,"href":"https:\/\/int03.co.uk\/blog\/wp-json\/wp\/v2\/posts\/844\/revisions\/860"}],"wp:attachment":[{"href":"https:\/\/int03.co.uk\/blog\/wp-json\/wp\/v2\/media?parent=844"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/int03.co.uk\/blog\/wp-json\/wp\/v2\/categories?post=844"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/int03.co.uk\/blog\/wp-json\/wp\/v2\/tags?post=844"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}