Advice? 1998 Mustang Gt Convt.

Katrina1998 · Jun 6, 2020

Hello! so I have 1998 mustang gt convertible and I have been dealing with this problem for some time now, my windshield wipers are stuck on, on the highest mode, occasionally when they are on (not often) they’ll randomly stop then go back to being on. So my short term solution has been to unplug the fuse. All my blinkers and headlights work. Any suggestions? I’ve previously had to replace the whole ecu on the car, but even with the old one, the wipers did the same thing.

white95 · Jun 6, 2020

Welcome to the forum. What other issues were you having that required the ecu to be replaced?

Katrina1998 · Jun 6, 2020

white95 said:
Welcome to the forum. What other issues were you having that required the ecu to be replaced?

Thanks! And the reason why I had to replace it was because my cylinders were misfiring, causing the idle to be all screwed up, thought it could’ve been the ignition coil packs or spark plugs, the plugs were fine. So I got new coil packs and that didn’t fix it, my father is a mechanic and tested all the voltages and came to the conclusion it had to be the computer

white95 · Jun 6, 2020

Fair enough. Always good to have a mechanic on your side!

Katrina1998 · Jun 6, 2020

Yes! Lol hopefully we can get these windshield wipers straightened out

Warhorse Racing · Jun 6, 2020

It could be the wiper/turn signal lever assembly (or the multifunction switch inside there) that has gone bad. You can get replacement assemblies (and switches) from LMR. If you are going to go through the trouble of taking it apart, it's worth checking to see if the stalk has been turned/broken out of position to hit the correct spot on the contacts.

My Fox Body (which has a similar wiper/turn assembly) had that issue. Somehow the stalk got over-rotated and the wipers only worked on high/low, nothing else. I took it apart (carefully), and I was able to put it back in the correct position. The wipers worked fine after that. That fix might also work on the 1998 wiper/turn signal assembly.

My 2000 GT wipers only worked on the off and high settings, but the stalk was in the correct position. I had to replace the wiper/turn signal lever assembly to solve that issue.

Does the stalk turn and stop in every position? Or is the stalk stuck in one place?

Katrina1998 · Jun 6, 2020

Warhorse Racing said:
It could be the wiper/turn signal lever assembly (or the multifunction switch inside there) that has gone bad. You can get replacement assemblies (and switches) from LMR. If you are going to go through the trouble of taking it apart, it's worth checking to see if the stalk has been turned/broken out of position to hit the correct spot on the contacts.

My Fox Body (which has a similar wiper/turn assembly) had that issue. Somehow the stalk got over-rotated and the wipers only worked on high/low, nothing else. I took it apart (carefully), and I was able to put it back in the correct position. The wipers worked fine after that. That fix might also work on the 1998 wiper/turn signal assembly.

My 2000 GT wipers only worked on the off and high settings, but the stalk was in the correct position. I had to replace the wiper/turn signal lever assembly to solve that issue.

Does the stalk turn and stop in every position? Or is the stalk stuck in one place?

Thanks! I’ll have to try that out and I’ll let ya know how it goes

PinkieT · Jun 6, 2020

I replaced the multi-function switch that has the turn signal stalk on my wife's 98 ragtop a few years ago. Not hard to do, IIRC. I found it at my local auto parts chain store back then. They still list it, $54. Good luck!

Katrina1998 · Jun 7, 2020

Warhorse Racing said:
It could be the wiper/turn signal lever assembly (or the multifunction switch inside there) that has gone bad. You can get replacement assemblies (and switches) from LMR. If you are going to go through the trouble of taking it apart, it's worth checking to see if the stalk has been turned/broken out of position to hit the correct spot on the contacts.

My Fox Body (which has a similar wiper/turn assembly) had that issue. Somehow the stalk got over-rotated and the wipers only worked on high/low, nothing else. I took it apart (carefully), and I was able to put it back in the correct position. The wipers worked fine after that. That fix might also work on the 1998 wiper/turn signal assembly.

My 2000 GT wipers only worked on the off and high settings, but the stalk was in the correct position. I had to replace the wiper/turn signal lever assembly to solve that issue.

Does the stalk turn and stop in every position? Or is the stalk stuck in one place?

it does turn and stop in all positions, seems to be fine

Warhorse Racing · Jun 7, 2020

Katrina1998 said:
it does turn and stop in all positions, seems to be fine

The next step would be to inspect the internals or replace the assembly.

It's not hard to remove the lever assembly. But, the clips holding the wiring in place can break if they have gotten brittle with age. The OEM assemblies run $100, the aftermarket version costs about $50. Or, you can make an attempt to disassemble the one you have and see if the contacts are corroded or the wiring is loose. There will probably be some small springs/parts inside, so be careful when taking it apart.