Temp gauge shoots up but my car isn’t overheating
Thread Starter
Honda-Tech Member
Joined: Dec 2018
Posts: 22
Likes: 0
Temp gauge shoots up but my car isn’t overheating
On my b20 swapped 99 ex coupe I had wired some coolant sensors wrong and I fixed them and double checked the coloring on the wires. Well now I noticed my temp gauge shoots right up but My car isn’t overheating? Fan switch is new and before I dump money on sensors I wanna know if anyone has some suggestions?
Honda-Tech Member
Joined: Nov 2004
Posts: 1,361
Likes: 0
Re: Temp gauge shoots up but my car isn’t overheating
Any chance there is air in the cooling system? I've had erratic gauge readings before when air was introduced after a radiator failure (crack at top endcap).
Honda-Tech Member
Joined: Jan 2019
Posts: 47
Likes: 2
Re: Temp gauge shoots up but my car isn’t overheating
Coolent sensor works off of resistance to ground. So with the sensor unplugged it will peg the gague one way and with the wire at the sensor grounded it will peg the other way. Im not sure on a honda which way it will go (as far as pegged hot/cold) but unplugged it should go to one extreme and grounded it will go to the other. If this is the case then the sensor is bad. If it doesn't we will need to dive into the wiring.
Honda-Tech Member
Joined: Feb 2016
Posts: 3,018
Likes: 52
Re: Temp gauge shoots up but my car isn’t overheating
The dash temperature gauge is driven by the sensor in the end of the head with one wire. That is the only thing that this sensor and wire does. The wire shorting to ground will cause the gauge needle to go up to hot. Wire open circuit makes it stay at cold.
Thread Starter
Honda-Tech Member
Joined: Dec 2018
Posts: 22
Likes: 0
Re: Temp gauge shoots up but my car isn’t overheating
I just changed my thermostat fan switch and Im not sure if I bleed all the air out but when I get home from work I can try to bleed it again and let you guys know if more air comes out and Ill inspect this radiator for any cracks or anything of that sort
Thread Starter
Honda-Tech Member
Joined: Dec 2018
Posts: 22
Likes: 0
Re: Temp gauge shoots up but my car isn’t overheating
Yay im not sure if that one wire ( sending unit ) connector is any good . I looked inside the plug lastnight and To me it didn’t look good. When I get home from work I can try to take a pic of inside that plug hopefully worse cause I just gotta get a new connector and not sensors ):
Thread Starter
Honda-Tech Member
Joined: Dec 2018
Posts: 22
Likes: 0
Re: Temp gauge shoots up but my car isn’t overheating
Coolent sensor works off of resistance to ground. So with the sensor unplugged it will peg the gague one way and with the wire at the sensor grounded it will peg the other way. Im not sure on a honda which way it will go (as far as pegged hot/cold) but unplugged it should go to one extreme and grounded it will go to the other. If this is the case then the sensor is bad. If it doesn't we will need to dive into the wiring.
Trending Topics
Honda-Tech Member
Joined: Oct 2012
Posts: 195
Likes: 2
Re: Temp gauge shoots up but my car isn’t overheating
See this thread: https://honda-tech.com/forums/honda-...94-ex-3097857/
I would be interested in knowing how you fix the connector if that is your problem.
I would be interested in knowing how you fix the connector if that is your problem.
Honda-Tech Member
Joined: Jan 2019
Posts: 47
Likes: 2
Re: Temp gauge shoots up but my car isn’t overheating
It could be the connector, bad sensor, broken wire or a list of other problems. Im assuming that the gauge pegs hot as soon as you turn the key on? If so we need to start by testing the sensor. You need to unplug the sensor and then connect that wire to ground. Turn the key on (you don't need to start the car), if the guage stays cold the sensor is bad. If the gauge still pegs hot, then we need to keep testing to find the problem
Honda-Tech Member
Joined: Feb 2016
Posts: 3,018
Likes: 52
Re: Temp gauge shoots up but my car isn’t overheating
If the wire is open the gauge should stay at cold. If it is shorted, it will go up to hot.
Unplug both ends of the wire (the sensor and the cluster) and check resistance to ground. It should be open circuit.
Unplug both ends of the wire (the sensor and the cluster) and check resistance to ground. It should be open circuit.
Thread Starter
Honda-Tech Member
Joined: Dec 2018
Posts: 22
Likes: 0
Re: Temp gauge shoots up but my car isn’t overheating
alright thanks I will do that today when I get home from work I haven’t had time to really do anything cause I been so busy with work. I will keep you guys updated Thanks
Honda-Tech Member
Joined: Aug 2018
Posts: 33
Likes: 0
Re: Temp gauge shoots up but my car isn’t overheating
alright guys I switched my cluster out with one of my friends and my temp gauge was reading👍🏼 So ima be buying a new em1 cluster soon
Honda-Tech Member
Joined: Aug 2018
Posts: 33
Likes: 0
Honda-Tech Member
Joined: Aug 2018
Posts: 33
Likes: 0
Thread
Thread Starter
Forum
Replies
Last Post
dlx111
Honda Civic / Del Sol (1992 - 2000)
3
May 10, 2018 09:57 PM